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  <front>
    <journal-meta>
      <journal-id journal-id-type="publisher-id">abc</journal-id>
      <journal-title-group>
        <journal-title>Arquivos Brasileiros de Cardiologia</journal-title>
        <abbrev-journal-title abbrev-type="publisher">Arq. Bras. Cardiol.</abbrev-journal-title>
      </journal-title-group>
      <issn pub-type="ppub">0066-782X</issn>
      <issn pub-type="epub">1678-4170</issn>
      <publisher>
        <publisher-name>Sociedade Brasileira de Cardiologia - SBC</publisher-name>
        <publisher-loc>S&#227;o Paulo, SP, Brazil</publisher-loc>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v3">MYvHRqKWFRQGpHMNqbFGzkJ</article-id>
      <article-id pub-id-type="other">00018</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v2">S0066-782X2011001400018</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v1">S0066-782X(11)09700518</article-id>
      <article-id pub-id-type="doi">10.1590/S0066-782X2011001400018</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Atualiza&#231;&#227;o Cl&#237;nica</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Biofilme em marca-passo artificial: fic&#231;&#227;o ou realidade?</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name>
            <surname>Santos</surname>
            <given-names>Ana Paula Azevedo</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Watanabe</surname>
            <given-names>Evandro</given-names>
          </name>
          <xref ref-type="aff" rid="aff02"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Andrade</surname>
            <given-names>Denise de</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
        </contrib>
      </contrib-group>
      <aff id="aff01">
        <addr-line>
          <named-content content-type="state">S&#227;o Paulo</named-content>
        </addr-line>
        <institution content-type="orgname">Universidade de S&#227;o Paulo</institution>
        <institution content-type="orgdiv1">Escola de Enfermagem de Ribeir&#227;o Preto </institution>
        <country country="BR">Brazil</country>
      </aff>
      <aff id="aff02">
        <addr-line>
          <named-content content-type="city">S&#227;o Paulo</named-content>
          <named-content content-type="state">S&#227;o Paulo</named-content>
        </addr-line>
        <institution content-type="orgname">Universidade de S&#227;o Paulo</institution>
        <institution content-type="orgdiv1">Faculdade de Odontologia de Ribeir&#227;o Preto </institution>
        <country country="BR">Brazil</country>
      </aff>
      <pub-date date-type="collection" publication-format="electronic">
        <month>11</month>
        <year>2011</year>
      </pub-date>
      <volume>97</volume>
      <issue>5</issue>
      <fpage>e113</fpage>
      <lpage>e120</lpage>
      <history>
        <date date-type="accepted">
          <day>13</day>
          <month>01</month>
          <year>2011</year>
        </date>
        <date date-type="rev-recd">
          <day>12</day>
          <month>01</month>
          <year>2011</year>
        </date>
        <date date-type="received">
          <day>27</day>
          <month>08</month>
          <year>2010</year>
        </date>
      </history>
      <permissions>
        <license license-type="open-access" xlink:href="http://creativecommons.org/licenses/by-nc/4.0/" xml:lang="en">
          <license-p>This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</license-p>
        </license>
      </permissions>
      <abstract>
        <p>A estimula&#231;&#227;o card&#237;aca artificial por meio de marca-passo card&#237;aco representa uma das alternativas mais promissoras no tratamento das arritmias, entretanto pode ocasionar rea&#231;&#245;es singulares ou complexas, precoces ou tardias. Neste estudo, objetivou-se descrever as evid&#234;ncias cient&#237;ficas sobre o risco de infec&#231;&#227;o e forma&#231;&#227;o de biofilme associado ao marca-passo card&#237;aco. Trata-se de um estudo de revis&#227;o integrativa da literatura. Totalizaram-se 14 publica&#231;&#245;es classificadas em tr&#234;s categorias tem&#225;ticas: diagn&#243;stico (microbiol&#243;gico e/ou cl&#237;nico), complica&#231;&#245;es e terap&#234;utica das infec&#231;&#245;es. Os Staphylococcus epidermidis e os Staphylococcus aureus foram os microrganismos mais frequentemente isolados. N&#227;o foi poss&#237;vel determinar a incid&#234;ncia da infec&#231;&#227;o associada aos marca-passos, uma vez que os estudos eram em geral de preval&#234;ncia. Em termos de terap&#234;utica destacou-se a remo&#231;&#227;o completa dos marca-passos, especialmente nos casos de suspeita de biofilme. Ainda &#233; controverso o uso da profilaxia antibi&#243;tica sist&#234;mica na redu&#231;&#227;o da incid&#234;ncia da infec&#231;&#227;o associada ao implante de marca-passo</p>
      </abstract>
      <kwd-group xml:lang="pt" kwd-group-type="author-generated">
        <kwd>Marca-passo artificial</kwd>
        <kwd>biofilmes</kwd>
        <kwd>infec&#231;&#245;es relacionadas &#224; pr&#243;tese</kwd>
      </kwd-group>
      <pub-date publication-format="electronic" date-type="pub">
        <day>20</day>
        <month>12</month>
        <year>2011</year>
      </pub-date>
    </article-meta>
  </front>
  <body>
    <p>
      <bold>ATUALIZA&#199;&#195;O CL&#205;NICA</bold>
    </p>
    <p>
      <bold>Biofilme em marca-passo artificial: fic&#231;&#227;o ou realidade?</bold>
    </p>
    <p>
      <bold>Ana Paula Azevedo Santos<sup>I</sup>; Evandro Watanabe<sup>II</sup>; Denise de Andrade<sup>I</sup></bold>
    </p>
    <p><sup>I</sup>Escola de Enfermagem de Ribeir&#227;o Preto - Universidade de S&#227;o Paulo </p>
    <p><sup>II</sup>Faculdade de Odontologia de Ribeir&#227;o Preto - Universidade de S&#227;o Paulo, S&#227;o Paulo, SP, Brasil</p>
    <p>
      <xref ref-type="corresp" rid="end">Correspond&#234;ncia</xref>
    </p>
    <p>
      <bold>RESUMO</bold>
    </p>
    <p>A estimula&#231;&#227;o card&#237;aca artificial por meio de marca-passo card&#237;aco representa uma das alternativas mais promissoras no tratamento das arritmias, entretanto pode ocasionar rea&#231;&#245;es singulares ou complexas, precoces ou tardias. Neste estudo, objetivou-se descrever as evid&#234;ncias cient&#237;ficas sobre o risco de infec&#231;&#227;o e forma&#231;&#227;o de biofilme associado ao marca-passo card&#237;aco. Trata-se de um estudo de revis&#227;o integrativa da literatura. Totalizaram-se 14 publica&#231;&#245;es classificadas em tr&#234;s categorias tem&#225;ticas: diagn&#243;stico (microbiol&#243;gico e/ou cl&#237;nico), complica&#231;&#245;es e terap&#234;utica das infec&#231;&#245;es. Os <italic>Staphylococcus epidermidis</italic> e os <italic>Staphylococcus aureus </italic>foram os microrganismos mais frequentemente isolados. N&#227;o foi poss&#237;vel determinar a incid&#234;ncia da infec&#231;&#227;o associada aos marca-passos, uma vez que os estudos eram em geral de preval&#234;ncia. Em termos de terap&#234;utica destacou-se a remo&#231;&#227;o completa dos marca-passos, especialmente nos casos de suspeita de biofilme. Ainda &#233; controverso o uso da profilaxia antibi&#243;tica sist&#234;mica na redu&#231;&#227;o da incid&#234;ncia da infec&#231;&#227;o associada ao implante de marca-passo.</p>
    <p><bold>Palavras-chave:</bold> Marca-passo artificial/tend&#234;ncias, biofilmes, infec&#231;&#245;es relacionadas &#224; pr&#243;tese.</p>
    <p>
      <bold>Introdu&#231;&#227;o</bold>
    </p>
    <p>A estimula&#231;&#227;o card&#237;aca artificial foi introduzida na pr&#225;tica cl&#237;nica nos anos 50 com o objetivo primordial de eliminar os sintomas e reduzir a mortalidade dos pacientes com bloqueios atrioventriculares avan&#231;ados. O avan&#231;o da tecnologia de fabrica&#231;&#227;o e de implante do marca-passo, aliado ao conhecimento eletrofisiopatol&#243;gico dos dist&#250;rbios de condu&#231;&#227;o card&#237;aca, permitiu um progresso consistente na estimula&#231;&#227;o card&#237;aca artificial, extremamente diversificada no seu modo de funcionamento, com alta confiabilidade, seguran&#231;a e cada vez mais fisiol&#243;gica<sup>1</sup>.</p>
    <p>Apesar da cirurgia de implante de marca-passo ser considerada de menor complexidade, &#233; importante atentar que, por ser um procedimento invasivo e representar um corpo estranho, coloca o paciente em risco para diversas complica&#231;&#245;es, ora decorrentes de falhas dos geradores, dano tecidual ou at&#233; da t&#233;cnica cir&#250;rgica de implante<sup>2,3</sup>. A diversidade de arsenal e de condutas tem proporcionado melhoria na t&#233;cnica cir&#250;rgica, entretanto, h&#225; escassez de informa&#231;&#245;es sobre as implica&#231;&#245;es e os efeitos destas melhorias<sup>4</sup>.</p>
    <p>Uma das preocupa&#231;&#245;es entre os profissionais &#233; o risco da forma&#231;&#227;o de biofilme e, consequentemente, de infec&#231;&#227;o. Nas &#250;ltimas d&#233;cadas, o biofilme tem sido largamente responsabilizado por infec&#231;&#245;es nosocomiais, especialmente nos implantes de pr&#243;teses, tubos, sondas e cateteres<sup>5-7</sup>. Especula-se que a presen&#231;a de marca-passos favore&#231;a a coloniza&#231;&#227;o microbiana, contribuindo sobremaneira para o desenvolvimento de biofilme, o que talvez possa justificar a ocorr&#234;ncia de endocardite<sup>6-10</sup>.</p>
    <p>&#201; oportuno destacar que o biofilme &#233; constitu&#237;do de uma comunidade estruturada por c&#233;lulas microbianas aderidas a uma superf&#237;cie s&#243;lida e envolta em matriz de subst&#226;ncias polim&#233;ricas extracelulares. Essa associa&#231;&#227;o microbiana constitui uma forma de prote&#231;&#227;o contra o seu desenvolvimento, fomentando rela&#231;&#245;es simbi&#243;ticas e de toler&#226;ncia aos antimicrobianos. A literatura sobre biofilme como fator de risco para sa&#250;de teve um avan&#231;o a partir da d&#233;cada de 90<sup>5</sup>. A forma&#231;&#227;o do biofilme envolve uma sequ&#234;ncia de eventos, como a ader&#234;ncia inicial revers&#237;vel dos microrganismos &#224; superf&#237;cie do substrato s&#243;lido, multiplica&#231;&#227;o microbiana, produ&#231;&#227;o da matriz de subst&#226;ncias polim&#233;ricas extracelulares e o desprendimento das c&#233;lulas s&#233;sseis, que, em forma planct&#244;nica, poder&#227;o ocasionar infec&#231;&#227;o ou a forma&#231;&#227;o de biofilme em outros locais.</p>
    <p>No biofilme, existem microcol&#244;nias heterog&#234;neas, constitu&#237;das de c&#233;lulas microbianas de uma (monomicrobiana) ou mais esp&#233;cies (polimicrobiana), funcionalmente organizadas, onde os microrganismos s&#227;o protegidos da a&#231;&#227;o dos macr&#243;fagos e antibi&#243;ticos. Mais ainda, o biofilme &#233; composto aproximadamente, entre 10 e 25%, por microrganismos, e, entre 75 e 90%, por subst&#226;ncias polim&#233;ricas extracelulares<sup>11</sup>.</p>
    <p>Uma das preocupa&#231;&#245;es entre os estudiosos &#233; o comprometimento infeccioso que o biofilme desencadeia e, em muitos casos de implantes, a substitui&#231;&#227;o do dispositivo &#233; a alternativa mais indicada<sup>11</sup>. Nesse sentido, acrescente-se que &#233; primordial a investiga&#231;&#227;o de biofilme quando houver persist&#234;ncia de infec&#231;&#227;o<sup>12</sup>.</p>
    <p>Particularmente, o implante de marca-passo &#233; um procedimento caracterizado por um baixo &#237;ndice de complica&#231;&#245;es, entretanto, a infec&#231;&#227;o, principalmente a de loja de fonte geradora, apresenta-se como uma das complica&#231;&#245;es mais comuns, com incid&#234;ncias variando entre 1-5%<sup>3-17</sup>. Apesar da baixa incid&#234;ncia, tais infec&#231;&#245;es apresentam evolu&#231;&#227;o preocupante e, na maioria das vezes, com alta morbidade e potencialmente fatais.</p>
    <p>Diversas condutas t&#234;m sido descritas para o tratamento da infec&#231;&#227;o de loja de marca-passo. As abordagens terap&#234;uticas mais conservadoras parecem cursar com maiores &#237;ndices de recidiva ou fal&#234;ncia de tratamento<sup>2-18</sup>, sendo os melhores resultados relacionados &#224;s abordagens mais agressivas, com remo&#231;&#227;o completa e implante de novos sistemas endoc&#225;rdicos<sup>3-8</sup>, conduta esta geralmente associada &#224; alta perman&#234;ncia hospitalar e aos elevados custos<sup>3</sup>.</p>
    <p>Diante do exposto, objetivou-se descrever as evid&#234;ncias cient&#237;ficas a respeito da forma&#231;&#227;o de biofilme e da ocorr&#234;ncia de infec&#231;&#227;o associadas aos marca-passos card&#237;acos a fim de identificar as principais recomenda&#231;&#245;es de preven&#231;&#227;o e controle. Tamb&#233;m se almeja avaliar nos estudos a incid&#234;ncia da infec&#231;&#227;o, bem como a microbiota presente em marca-passos. Buscou-se como referencial te&#243;rico a Pr&#225;tica Baseada em Evid&#234;ncias que, diante de um problema cl&#237;nico, permite avaliar criticamente a produ&#231;&#227;o do conhecimento cient&#237;fico para subsidiar a tomada de decis&#227;o<sup>19</sup>.</p>
    <p>
      <bold>M&#233;todos</bold>
    </p>
    <p>O m&#233;todo utilizado foi revis&#227;o integrativa da literatura, que faz parte da Pr&#225;tica Baseada em Evid&#234;ncias e que permite a s&#237;ntese das evid&#234;ncias dispon&#237;veis sobre uma delimitada quest&#227;o, contribuindo para o aprofundamento do conhecimento sobre o tema investigado<sup>19</sup>.</p>
    <p>A sele&#231;&#227;o dos artigos foi subsidiada no questionamento:<italic> O que tem sido publicado sobre a forma&#231;&#227;o de biofilme e a ocorr&#234;ncia de infec&#231;&#227;o relacionada aos marca-passos card&#237;acos?</italic></p>
    <p>Para a busca dos artigos, foram utilizadas as bases de dados <italic>Medical Literature Analysis and Retrieval System</italic> (MEDLINE), Literatura Latino-Americana e do Caribe em Ci&#234;ncias da Sa&#250;de (LILACS), <italic>Cumulative Index to Nursing and Allied Health Literature</italic> (CINAHL) e Biblioteca Cochrane, com acesso via internet. Os descritores foram biofilmes (<italic>biofilms</italic>), marca-passo artificial card&#237;aco (<italic>pacemakers artificial cardiac)</italic> e infec&#231;&#227;o (<italic>infection</italic>), selecionadas a partir das defini&#231;&#245;es no <italic>Medical Subject Headings</italic> (MESH) e nos Descritores em Ci&#234;ncias da Sa&#250;de (DeCs) da Biblioteca Virtual em Sa&#250;de (BVS).</p>
    <p>Os estudos selecionados foram classificados segundo n&#237;vel de evid&#234;ncia: 01) revis&#227;o sistem&#225;tica ou metan&#225;lise de ensaios cl&#237;nicos randomizados controlados; 02) pelo menos um ensaio cl&#237;nico randomizado controlado bem delineado; 03) ensaios cl&#237;nicos bem delineados sem randomiza&#231;&#227;o; 04) provenientes de coorte e caso-controle bem delineados; 05) revis&#227;o sistem&#225;tica de estudos descritivos e qualitativos; 06) &#250;nico estudo descritivo ou qualitativo; e 07) opini&#227;o de autoridades ou relat&#243;rios de comit&#234;s de especialistas<sup>20</sup>.</p>
    <p>As publica&#231;&#245;es sobre a tem&#225;tica obtidas na &#237;ntegra, nos idiomas portugu&#234;s, ingl&#234;s e espanhol, foram inclu&#237;das. Como crit&#233;rios de exclus&#227;o estabeleceram-se: estudos estruturados em modelo animal e aqueles referentes exclusivamente &#224; t&#233;cnica de implante de marca-passo. Assim, mediante a leitura criteriosa do t&#237;tulo e resumo do artigo, a fim de verificar a adequa&#231;&#227;o com a quest&#227;o norteadora, totalizou-se 14 publica&#231;&#245;es, 05 no MEDLINE, dois no LILACS, 05 no CINAHL e tr&#234;s na Biblioteca Cochrane, sendo que, um mesmo artigo foi identificado em duas bases de dados.</p>
    <p>
      <bold>Resultados e discuss&#227;o</bold>
    </p>
    <p>Totalizaram-se 14 publica&#231;&#245;es a partir de 1984, sendo 06 realizadas nos Estados Unidos, duas na Espanha, e apenas uma na &#193;ustria, uma no Brasil, uma no Canad&#225;, uma na Finl&#226;ndia, uma na Fran&#231;a e uma na Su&#233;cia. Nesse sentido, 12 eram no idioma ingl&#234;s, uma em portugu&#234;s e uma em espanhol. No <xref ref-type="fig" rid="a18qd01m">Quadro 1</xref>, tem-se a apresenta&#231;&#227;o dos diferentes delineamentos dos estudos e dos n&#237;veis de evid&#234;ncias. Assim, nenhum estudo de revis&#227;o sistem&#225;tica ou metan&#225;lise de ensaios cl&#237;nicos randomizados controlados foi evidenciado, apenas dois (14,3%) com n&#237;vel de evid&#234;ncia 02, 08 (57,1%) com n&#237;vel 04 (coorte e caso-controle bem delineados) e 04 (28,6%) com n&#237;veis 06 e 07.</p>
    <p content-type="asset">
      <fig id="a18qd01m">
        <graphic xlink:href="1678-4170-abc-97-05-e113-00018-gf01.jpg"/></fig>
    </p>
    <p>O <xref ref-type="fig" rid="a18qd02m">Quadro 2</xref>, sinopse das publica&#231;&#245;es acerca das infec&#231;&#245;es decorrentes dos implantes de marca-passos card&#237;acos, revelou que o foco de aten&#231;&#227;o dos pesquisadores permearam aspectos relacionados &#224; microbiologia, &#224; cl&#237;nica, &#224;s complica&#231;&#245;es e &#224; terap&#234;utica. Especialmente sobre a tem&#225;tica biofilme em marca-passos, verificou-se apenas dois (14,3%) trabalhos. Especula-se que a ocorr&#234;ncia da forma&#231;&#227;o de biofilme &#233; inevit&#225;vel, entretanto a sua confirma&#231;&#227;o em marca-passos envolve a remo&#231;&#227;o do artefato implantado, bem como tecnologia avan&#231;ada de microscopia eletr&#244;nica de varredura.</p>
    <p content-type="asset">
      <fig id="a18qd02m">
        <graphic xlink:href="1678-4170-abc-97-05-e113-00018-gf02.jpg"/></fig>
    </p>
    <p>No que concerne aos aspectos de etiologia microbiana, verificou-se uma preocupa&#231;&#227;o centrada na esp&#233;cie e no perfil de sensibilidade ou multirresist&#234;ncia das cepas aos antimicrobianos. A &#234;nfase &#233; a adequa&#231;&#227;o da terap&#234;utica antimicrobiana. Do total, apenas dois (14,3%) estudos foram ensaios cl&#237;nicos sobre antibioticoterapia profil&#225;tica. Tema esse ainda pol&#234;mico entre cirurgi&#245;es e infectologistas, seja na profilaxia e/ou terap&#234;utica.</p>
    <p>Cabe destacar que os resultados desta pesquisa n&#227;o permitem determinar a real situa&#231;&#227;o da ocorr&#234;ncia de infec&#231;&#227;o associada aos marca-passos, uma vez que os estudos se reportam a situa&#231;&#245;es isoladas. Nesse sentido, os dados sobre a ocorr&#234;ncia de biofilme em marca-passos s&#227;o escassos, considerando tratar-se de um agravo complexo e de dif&#237;cil diagn&#243;stico. Adicione-se que a popula&#231;&#227;o propensa ao uso desse dispositivo, em geral, &#233; de idosos com antecedentes de arritmias, faixa et&#225;ria elevada e, portanto, com maior probabilidade de complica&#231;&#245;es infecciosas. Outro aspecto que dificulta a notifica&#231;&#227;o &#233; que o aparecimento dos sintomas de infec&#231;&#227;o pode ser tardio, muitas vezes n&#227;o associado e nem tratado como biofilme.</p>
    <p>No entanto, a incid&#234;ncia de infec&#231;&#245;es relacionadas a dispositivos card&#237;acos foi relatada entre 0,5% e 12%. Em publica&#231;&#245;es recentes, a incid&#234;ncia &#233; menor do que 5%%<sup>8 </sup>ou se aproxima de 7%%<sup>21</sup>. A endocardite associada ao eletrodo do marca-passo &#233; rara, mas sua ocorr&#234;ncia &#233; considerada uma infec&#231;&#227;o grave. Estimou-se que sua incid&#234;ncia entre endocardites &#233; de 19,9%, no entanto, esta taxa provavelmente tem sido superestimada pela aus&#234;ncia de crit&#233;rios rigorosos de diagn&#243;stico. Endocardite associada ao eletrodo do marca-passo foi descrita em 16 pacientes do grupo de remo&#231;&#227;o transvenosa e 11 do grupo de circula&#231;&#227;o extracorp&#243;rea<sup>10</sup>.</p>
    <p>Nos Estados Unidos, anualmente cerca de um milh&#227;o de casos de infec&#231;&#245;es nosocomiais est&#225; associada a dispositivos e cerca de dois ter&#231;os s&#227;o causados por <italic>Staphylococcus aureus</italic> ou <italic>Staphylococcus epidermidis</italic><sup>12</sup>. Ainda aproximadamente 1%% dos pacientes com estimuladores endocard&#237;acos desenvolveu sepse<sup>22</sup>. Infec&#231;&#245;es associadas a marca-passos geralmente s&#227;o causadas por <italic>S. epidermidis </italic>ou <italic>S. aureus</italic><sup>4,9,12,24,26,27</sup>, houve apenas um caso de infec&#231;&#227;o por <italic>Aspergillus</italic> spp.<sup>23</sup>. Greenspon e cols.<sup>9</sup> mostraram que <italic>S. aureus</italic> foi a causa mais comum de endocardite associada ao marca-passo (53%%), seguido por <italic>S. epidermidis </italic>(22%%) e estreptococos (12%%). As infec&#231;&#245;es precoces ocorreram no prazo de 06 meses e as tardias em aproximadamente 32 meses. Tamb&#233;m destacaram que a microbiota da pele &#233; a origem prov&#225;vel para endocardite associada ao eletrodo do marca-passo<sup>9</sup>. Esses dados nos remetem aos estudos sobre a forma&#231;&#227;o de biofilme que justifica o tempo prolongado para o aparecimento dos primeiros sintomas de infec&#231;&#227;o.</p>
    <p>Em outro estudo, <italic>S. epidermidis</italic> foi o microrganismo que causou mais infec&#231;&#245;es relacionadas aos marca-passos<sup>24</sup>. Sendo que a infec&#231;&#227;o pode envolver qualquer parte do marca-passo: a bolsa, os eletrodos e a &#225;rea de implante dos eletrodos no endoc&#225;rdio<sup>21</sup>. Al&#233;m disso, a forma&#231;&#227;o do biofilme por <italic>S. epidermidis </italic>pode ser influenciada pela superf&#237;cie do metal<sup>18</sup>.</p>
    <p>As infec&#231;&#245;es associadas a implantes cir&#250;rgicos s&#227;o geralmente mais dif&#237;ceis de tratar, pois requerem um longo per&#237;odo de terapia com antibi&#243;ticos e repetidos procedimentos cir&#250;rgicos, com dr&#225;sticas consequ&#234;ncias cl&#237;nicas e econ&#244;micas. A mortalidade &#233; mais elevada entre pacientes com implantes cardiovasculares e o custo do dispositivo constitui uma pequena fra&#231;&#227;o em rela&#231;&#227;o ao montante destinado ao tratamento da infec&#231;&#227;o relacionada ao implante. Os objetivos cl&#237;nicos mais importantes no tratamento dessas infec&#231;&#245;es s&#227;o: tratar a infec&#231;&#227;o, evitar a reincid&#234;ncia, preservar a fun&#231;&#227;o, anular o risco de endocardite e reduzir o risco de morte. Na maioria das vezes, esses objetivos podem ser alcan&#231;ados pela terapia antimicrobiana e interven&#231;&#227;o cir&#250;rgica. E, talvez, avan&#231;ar na confec&#231;&#227;o e utiliza&#231;&#227;o de marca-passos card&#237;acos impregnados com agentes antimicrobianos. O diagn&#243;stico de infec&#231;&#227;o pelo implante exige a presen&#231;a de manifesta&#231;&#245;es cl&#237;nicas e de agentes pat&#243;genos em amostras cir&#250;rgicas, sendo que culturas de sangue podem ser negativas em casos de infec&#231;&#227;o relacionada &#224; marca-passos, salvo na endocardite associada<sup>12</sup>.</p>
    <p>Em um estudo sobre diferentes modalidades de tratamento de 38 pacientes com infec&#231;&#227;o relacionada ao dispositivo card&#237;aco, obtiveram 12 pacientes tratados apenas com antibi&#243;ticos, 19 tiveram a remo&#231;&#227;o do dispositivo, reimplante seguido por curtos per&#237;odos de antibi&#243;ticos (10-14 dias) e 07 pacientes receberam um per&#237;odo maior de 06 semanas de antimicrobiano. No primeiro grupo, houve reincid&#234;ncia da infec&#231;&#227;o e, nos outros dois, os pacientes tiveram a infec&#231;&#227;o completamente resolvida. Isso demonstra a import&#226;ncia da remo&#231;&#227;o do dispositivo no tratamento dessas infec&#231;&#245;es<sup>21</sup>.</p>
    <p>De acordo com Darouiche<sup>12</sup>, a maioria dos implantes contaminados por <italic>S. aureus</italic> ou <italic>Candida</italic> spp. requer a remo&#231;&#227;o cir&#250;rgica. O autor justifica que &#233; indicada a remo&#231;&#227;o total mesmo que a contamina&#231;&#227;o esteja somente na bolsa do marca-passo, pois, as outras partes do dispositivo tamb&#233;m podem estar contaminadas. J&#225; nos pacientes que respondem &#224; terapia medicamentosa, o implante n&#227;o deve ser retirado. Embora a remo&#231;&#227;o do implante esteja associada &#224; solu&#231;&#227;o da infec&#231;&#227;o, ela tem que ser autorizada nos pacientes que apresentam risco de complica&#231;&#245;es intraoperat&#243;rias e p&#243;s-operat&#243;rias<sup>12</sup>.</p>
    <p>Como mencionado, a terap&#234;utica da infec&#231;&#227;o associada ao sistema de marca-passo card&#237;aco artificial &#233; diversa. Nos casos de comprometimento sist&#234;mico com sepse ou endocardite, ainda h&#225; uma tend&#234;ncia &#224;s abordagens mais agressivas com antibioticoterapia endovenosa prolongada (04 - 12 semanas), remo&#231;&#227;o e troca completa dos sistemas endoc&#225;rdicos.</p>
    <p>O resultado da cultura microbiana &#233; outro aspecto que direciona a terap&#234;utica, ou seja, abordagem conservadora nos casos de <italic>S. epidermidis</italic> ou interven&#231;&#227;o agressiva para o <italic>S. aureus </italic>t&#234;m sido as aconselhadas. Assim, utiliza-se a antibioticoterapia associada ao reposicionamento do gerador ou &#224; remo&#231;&#227;o completa dos sistemas endoc&#225;rdicos e implante de um novo, antibioticoterapia associada a medidas locais e irriga&#231;&#227;o, dentre outras. Todas articuladas a longos per&#237;odos de interna&#231;&#227;o, altos custos e resultados controversos. A t&#233;cnica de implante subpeitoral mostrou-se como uma alternativa vi&#225;vel no tratamento da infec&#231;&#227;o da loja de fonte geradora de marca-passo, apresentando 100% de efic&#225;cia, um curto per&#237;odo de interna&#231;&#227;o e um menor custo. No entanto, ainda s&#227;o necess&#225;rios estudos e seguimentos para uma conclus&#227;o definitiva<sup>3-12</sup>.</p>
    <p>Estudiosos revelaram que a sinergia de diferentes combina&#231;&#245;es de antibi&#243;ticos contra biofilmes de<italic> S. epidermidis</italic> variou com o tempo de forma&#231;&#227;o destes biofilmes (06, 24, 48 horas). Em geral, todas as combina&#231;&#245;es de antibi&#243;ticos foram eficazes em biofilmes novos. A combina&#231;&#227;o entre vancomicina e rifampicina teve efeito bactericida em 06 horas, e nos biofilmes antigos, as combina&#231;&#245;es com tetraciclina foram mais eficazes. Ficou evidente a dificuldade de erradicar os biofilmes mais antigos<sup>21,23</sup>.</p>
    <p>Existem genes de media&#231;&#227;o de forma&#231;&#227;o de biofilme, tais como genes de anexo (fbe e atlE) e ader&#234;ncia (ica), que foram observados na maioria das cepas de <italic>S. epidermidis</italic> isoladas de pacientes com marca-passo. Esses dados indicam um papel importante dos genes de ader&#234;ncia nas infec&#231;&#245;es em marca-passos<sup>24</sup>.</p>
    <p>No estudo de Marrie e cols.<sup>22</sup>,a microscopia eletr&#244;nica de varredura revelou uma coloniza&#231;&#227;o diferente no eletrodo do marca-passo e o microrganismo <italic>S. aureus</italic> foi isolado em v&#225;rios s&#237;tios. Um extenso biofilme na superf&#237;cie interna do eletrodo foi evidenciado e na superf&#237;cie externa havia uma enorme massa de biofilme com uma popula&#231;&#227;o de c&#233;lulas bacterianas aderidas.Todas as &#225;reas com fissuras acumularam biofilme, o que talvez justifique a dificuldade de a&#231;&#227;o da terapia com antibi&#243;ticos<sup>22</sup>. Por isso, na maioria dos casos, a remo&#231;&#227;o dos sistemas endoc&#225;rdicos &#233; indicada<sup>2-10,12,22</sup>.</p>
    <p>De maneira controversa,Bluhm e cols.<sup>4</sup> explicam que o uso de t&#233;cnica cir&#250;rgica moderna articulada a meticulosa pr&#225;tica de assepsia exclui o uso da profilaxia antibi&#243;tica sist&#234;mica no implante de marca-passo.</p>
    <p>H&#225; raz&#245;es para esperar que a evolu&#231;&#227;o da tecnologia de marca-passos tenha impacto sobre a redu&#231;&#227;o das taxas de complica&#231;&#245;es. Aspectos como o tamanho reduzido do gerador, a qualidade e durabilidade dos eletrodos aumentaram, t&#233;cnicas de implante e de assepsia foram aperfei&#231;oadas. Entretanto, os estimuladores implantados do tipo c&#226;mara dupla, com introdu&#231;&#227;o de dois eletrodos, resultam em tempo de implante mais longo, aumentando as taxas de complica&#231;&#245;es. No acompanhamento de 27 meses ap&#243;s o implante, aproximadamente 14% dos pacientes sofreram uma complica&#231;&#227;o. Na maioria dos casos, as complica&#231;&#245;es do ponto de vista cl&#237;nico eram baixas e sem &#243;bito. Nesse estudo, as taxas de infec&#231;&#227;o foram semelhantes em pacientes que receberam antibi&#243;ticos (1,2%) e os que n&#227;o receberam (1,7%), por&#233;m n&#227;o houve aleatoriza&#231;&#227;o dos participantes nos grupos<sup>25</sup>. O benef&#237;cio da administra&#231;&#227;o de antibi&#243;ticos para reduzir o risco de infec&#231;&#245;es ainda &#233; pol&#234;mico.</p>
    <p>Ainda &#233; oportuno destacar os seguintes fatos:</p>
    <disp-quote>
      <p>&#149; A forma&#231;&#227;o de polissacar&#237;deo extracelular por <italic>S. epidermidis </italic>foi consideravelmente maior em marca-passos do que nos cateteres intravenosos, o que torna a amea&#231;a por biofilme ainda maior<sup>26</sup>.</p>
      <p>&#149; As dificuldades inerentes &#224; seguran&#231;a do reprocessamento de artigos tamb&#233;m representa um elevado risco de contamina&#231;&#227;o. H&#225; relato de reprocessamento de marca-passos retirados de pacientes que estavam com infec&#231;&#227;o<sup>2</sup>.</p>
      <p>&#149; A profilaxia antibi&#243;tica, embora controversa, parece promissora na preven&#231;&#227;o de complica&#231;&#245;es infecciosas ap&#243;s implante de marca-passo<sup>8,10,27</sup>.</p>
      <p>&#149; Em termos de perfil de sensibilidade, estudiosos verificaram que 67% das infec&#231;&#245;es estavam associadas ao <italic>S. aureus</italic> resistente &#224; meticilina, sugerindo que este &#233; um agente patog&#234;nico importante para endocardite associada ao eletrodo do marca-passo<sup>9</sup>.</p>
      <p>&#149; Uma nova t&#233;cnica para o manejo da infec&#231;&#227;o de loja de marca-passo sem a retirada dos sistemas endoc&#225;rdicos mostrou-se, a princ&#237;pio, uma alternativa vi&#225;vel e com baixo custo, no entanto, ainda &#233; necess&#225;rio estudos de seguimento para uma conclus&#227;o definitiva<sup>3</sup>. Esse foi o &#250;nico estudo que prop&#244;s uma alternativa para o tratamento da infec&#231;&#227;o relacionada ao marca-passo e que teve bons resultados.</p>
      <p>&#149; Das complica&#231;&#245;es relacionadas ao marca-passo, 6,7% foram precoces e 7,2% tardias, sendo 3,1% relacionadas &#224; implante<sup>25</sup>. No estudo de Maduro Maytin e cols.<sup>2</sup>, a infec&#231;&#227;o na bolsa do marca-passo foi uma complica&#231;&#227;o relacionada a reinterven&#231;&#245;es tardias (0,4%).</p>
      <p>&#149; Em rela&#231;&#227;o ao biofilme, os genes de ader&#234;ncia foram quase sempre presentes em esp&#233;cies recuperadas de pacientes com marca-passo, indicando o papel importante destes genes nos mecanismos de patogenicidade da infec&#231;&#227;o relacionadas ao marca-passo<sup>24</sup>. Diferen&#231;as de morfologias do biofilme podem refletir o grau ao qual a fibrina e outros materiais tornam-se incorporados ao biofilme em desenvolvimento<sup>26</sup>. A idade do biofilme pode interferir na a&#231;&#227;o do antibi&#243;tico, j&#225; que s&#227;o mais eficazes nos biofilmes mais jovens. Ainda preveem que a resist&#234;ncia dos microrganismos aos antibi&#243;ticos tornar&#225; o tratamento das infec&#231;&#245;es cardiovasculares mais dif&#237;ceis<sup>21</sup>.</p>
    </disp-quote>
    <p>A profilaxia antibi&#243;tica sist&#234;mica reduz significativamente a incid&#234;ncia de complica&#231;&#245;es infecciosas ap&#243;s o implante de marca-passo permanente<sup>8,10,27</sup>. Em outra investiga&#231;&#227;o, n&#227;o houve recorr&#234;ncia de infec&#231;&#227;o ap&#243;s a remo&#231;&#227;o do eletrodo do marca-passo, sendo um procedimento eficaz que pode ser aplicado mesmo em pacientes que demonstram biofilmes maiores que um cent&#237;metro. Por conseguinte, no marca-passo com biofilmes maiores que dois cent&#237;metros de di&#226;metro, a recomenda&#231;&#227;o foi a remo&#231;&#227;o<sup>10</sup>. Maduro Maytin e cols.<sup>2</sup> realizaram profilaxia com antibi&#243;ticos em 24 horas antes do implante do marca-passo e 05 dias ap&#243;s, com um total de 0,4% de infec&#231;&#245;es tardias em reinterven&#231;&#245;es. Nesse particular, pesquisadores observaram que as infec&#231;&#245;es ocorreram nos pacientes que n&#227;o receberam profilaxia com antibi&#243;ticos<sup>27</sup>. Posto isso, as evid&#234;ncias s&#227;o contundentes de que a melhor abordagem na erradica&#231;&#227;o da infec&#231;&#227;o associada a implantes de biomateriais e diminui&#231;&#227;o da mortalidade &#233; a interven&#231;&#227;o cir&#250;rgica<sup>2-10,12,26</sup>. Parece-nos consenso de que todos os sistemas endoc&#225;rdicos devem ser totalmente removidos para erradicar definitivamente a infec&#231;&#227;o por forma&#231;&#227;o de biofilme.</p>
    <p>
      <bold>Conclus&#227;o</bold>
    </p>
    <p>O biofilme &#233; um tema atual e ainda pouco estudado na &#225;rea da cardiologia e menos ainda quando relacionado ao marca-passo. As condi&#231;&#245;es relativas &#224; natureza do biomaterial, somadas aos fatores de riscos inerentes aos pacientes, como extremos de idade, imunocomprometimento de causas variadas, doen&#231;as de base, caracterizam o perfil da situa&#231;&#227;o que merece aten&#231;&#227;o. Nesse particular, pesquisas adicionais s&#227;o necess&#225;rias para determinar a situa&#231;&#227;o atual das complica&#231;&#245;es advindas do uso de marca-passos em diferentes popula&#231;&#245;es de pacientes, considerando que os estudos analisados individualmente n&#227;o sinalizaram diferen&#231;as estatisticamente significantes em rela&#231;&#227;o &#224;s taxas de infec&#231;&#227;o.</p>
    <p>Por outro lado, nenhum estudo explorou a natureza de biomateriais que constituem os marca-passos e a forma&#231;&#227;o de biofilme. Assim, questiona-se: ser&#225; que marca-passos impregnados com antimicrobianos reduziriam ou inibiriam a forma&#231;&#227;o de biofilme?</p>
    <p>Em s&#237;ntese, os dados analisados mostram que o tema &#233; de grande import&#226;ncia e tem sido pouco estudado, uma vez que em 24 anos somente 14 artigos foram publicados. Com rela&#231;&#227;o ao profissional da enfermagem, mesmo que desempenhe um papel fundamental na assist&#234;ncia direta e/ou indireta ao paciente sujeito ao uso de marca-passo, tanto no implante como no acompanhamento, especialmente na detec&#231;&#227;o de sinais e sintomas de infec&#231;&#227;o, sua participa&#231;&#227;o foi nula nesses estudos. Diante do risco de infec&#231;&#227;o associada a procedimentos invasivos, vale ressaltar o valor das medidas de preven&#231;&#227;o.</p>
    <p>Fica-nos tamb&#233;m a reflex&#227;o acerca da import&#226;ncia das medidas de vigil&#226;ncia epidemiol&#243;gica das infec&#231;&#245;es, principalmente no Brasil, pa&#237;s marcado pela diversidade cultural, por desigualdades socioecon&#244;micas, por heterog&#234;neos padr&#245;es de atendimento &#224; sa&#250;de, em termos de estrutura f&#237;sica, tipo de clientela e ocorr&#234;ncia de infec&#231;&#227;o. Adicione-se que, historicamente, o sistema de sa&#250;de nacional enfrenta o grave problema da amplia&#231;&#227;o social, o que se alia &#224; car&#234;ncia quantitativa de recursos humanos e &#224; inapropriada obten&#231;&#227;o de tecnologia. Sem d&#250;vida, s&#227;o condi&#231;&#245;es f&#233;rteis para eleva&#231;&#227;o dos &#237;ndices de infec&#231;&#227;o.</p>
    <p>
      <bold>Potencial Conflito de Interesses</bold>
    </p>
    <p>Declaro n&#227;o haver conflito de interesses pertinentes.</p>
    <p>
      <bold>Fontes de Financiamento</bold>
    </p>
    <p>O presente estudo n&#227;o teve fontes de financiamento externas.</p>
    <p>
      <bold>Vincula&#231;&#227;o Acad&#234;mica</bold>
    </p>
    <p>N&#227;o h&#225; vincula&#231;&#227;o deste estudo a programas de p&#243;s-gradua&#231;&#227;o.</p>
    <p>
      <fn id="end" fn-type="corresp">
        <label>
          <bold> Correspond&#234;ncia:</bold>
        </label>
        <p> Denise de Andrade </p>
        <p> Avenida dos Bandeirantes, 3900 - Campus Universit&#225;rio - Monte Alegre </p>
        <p> 14040-902 - Ribeir&#227;o Preto, SP, Brasil </p>
        <p> E-mail: </p>
        <p>
          <email xlink:href="dandrade@eerp.usp.br">dandrade@eerp.usp.br</email>
        </p>
      </fn>
    </p>
    <p>Artigo recebido em 27/08/10; revisado recebido em 12/01/11; aceito em 13/01/11.</p>
  </body>
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  <sub-article article-type="translation" id="TRen" xml:lang="en">
    <front-stub>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Clinical Update</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title xml:lang="en">Biofilm on artificial pacemaker: fiction or reality?</article-title>
      </title-group>
      <abstract xml:lang="en">
        <p>Cardiac pacing through cardiac pacemaker is one of the most promising alternatives in the treatment of arrhythmias, but it can cause reactions natural or complex reactions, either early or late. This study aimed to describe the scientific evidence on the risk of infection and biofilm formation associated with cardiac pacemaker. This is a study of integrative literature review. It included 14 publications classified into three thematic categories: diagnosis (microbiological and/or clinical), complications and therapy of infections. Staphylococcus epidermidis and Staphylococcus aureus were the microorganisms most frequently isolated. It was not possible to determine the incidence of infection associated with pacemakers, since the studies were generally of prevalence. In terms of therapy, the complete removal of pacemakers stood out, especially in cases of suspected biofilm. Still controversial is the use of systemic antibiotic prophylaxis in reducing the incidence of infection associated with implantation of a pacemaker</p>
      </abstract>
      <kwd-group xml:lang="en">
        <kwd>Pacemaker</kwd>
        <kwd>artificial</kwd>
        <kwd>biofilms</kwd>
        <kwd>prosthesis-related infections</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <p>
        <bold>CLINICAL UPDATE</bold>
      </p>
      <p>
        <fn id="enda-body2">
          <label>
            <bold>Biofilm on artificial pacemaker: fiction or reality?</bold>
          </label>
          <p>
            <bold>Ana Paula Azevedo Santos<sup>I</sup>; Evandro Watanabe<sup>II</sup>; Denise de Andrade<sup>I</sup></bold>
          </p>
        </fn>
      </p>
      <p><sup>I</sup>Escola de Enfermagem de Ribeir&#227;o Preto - Universidade de S&#227;o Paulo</p>
      <p><sup>II</sup>Faculdade de Odontologia de Ribeir&#227;o Preto - Universidade de S&#227;o Paulo, S&#227;o Paulo, SP, Brasil</p>
      <p>Mailing address</p>
      <p>
        <bold>ABSTRACT</bold>
      </p>
      <p>Cardiac pacing through cardiac pacemaker is one of the most promising alternatives in the treatment of arrhythmias, but it can cause reactions natural or complex reactions, either early or late. This study aimed to describe the scientific evidence on the risk of infection and biofilm formation associated with cardiac pacemaker. This is a study of integrative literature review. It included 14 publications classified into three thematic categories: diagnosis (microbiological and/or clinical), complications and therapy of infections. <italic>Staphylococcus epidermidis</italic> and <italic>Staphylococcus aureus</italic> were the microorganisms most frequently isolated. It was not possible to determine the incidence of infection associated with pacemakers, since the studies were generally of prevalence. In terms of therapy, the complete removal of pacemakers stood out, especially in cases of suspected biofilm. Still controversial is the use of systemic antibiotic prophylaxis in reducing the incidence of infection associated with implantation of a pacemaker.</p>
      <p><bold>Keywords:</bold> Pacemaker, artificial/trends; biofilms; prosthesis-related infections.</p>
      <p>
        <bold>Introduction</bold>
      </p>
      <p>Cardiac pacing was introduced into clinical practice in the 50s with the primary objective of eliminating the symptoms and reducing mortality of patients with advanced atrioventricular blocks. Advances in pacemaker manufacturing and implantation technology, plus the electrophysiology knowledge of cardiac conduction disorders, enabled a consistent progress in cardiac pacing, extremely diverse in its mode of operation, with high physiological reliability and safety<sup>1</sup>.</p>
      <p>Although pacemaker implantation surgery is considered less complex, it is important to observe that, for being an invasive procedure and representing a foreign body, it puts the patient at risk for various complications, sometimes due to failures of generators, tissue damage or due to the implantation technique<sup>2,3</sup>. The diversity of techniques and conducts has provided improvement in surgical technique, however, there is limited information on the implications and effects of these improvements<sup>4</sup>.</p>
      <p>One concern among professionals is the risk of biofilm formation and, consequently, infection. In recent decades, biofilms have been widely blamed for nosocomial infections, especially in prosthetic implants, tubes, probes and catheters<sup>5-7</sup>. It is speculated that the presence of pacemakers is conducive to microbial colonization, contributing greatly to the development of biofilm, which could explain the occurrence of endocarditis<sup>6-10</sup>.</p>
      <p>It is worth noting that the biofilm consists of a structured community of microbial cells adhered to a solid surface surrounded by a matrix of extracellular polymeric substances. This microbial association is a form of protection against its development, encouraging symbiotic relationships and tolerance to antimicrobials. The literature on biofilm as a risk factor for health progressed from the 90s<sup>5</sup>. The biofilm formation involves a sequence of events, such as the initial reversible adherence of microorganisms to the surface of the solid substrate, microbial growth, matrix production of extracellular polymeric substances and detachment of sessile cells, which in planktonic form may cause infection or biofilm formation in other locations.</p>
      <p>In biofilms, microcolonies are heterogeneous, consisting of microbial cells of one (monomicrobial) or more species (polymicrobial), functionally organized, where the organisms are protected from the action of macrophages and antibiotics. Moreover, the biofilm is roughly composed of 10 to 25% microorganisms, and 75 to 90% extracellular polymeric substances<sup>11</sup>.</p>
      <p>One concern among scholars is the infection that the biofilm triggers, and in many cases of implants, device replacement is the alternative indicated<sup>11</sup>. Accordingly, it is worth noting that it is crucial to investigate the biofilm when there is persistence of infection<sup>12</sup>.</p>
      <p>Particularly, the implantation of pacemakers is a procedure characterized by a low complication rate, however, infections, mainly that of pacemaker generator pocket is one of the most common complications with incidences ranging from 1-5%<sup>3-17</sup>. Despite the low incidence, such infections have a worrying development mostly often with high morbidity and potentially fatal.</p>
      <p>Several conducts have been described for the treatment of infection of pacemaker pocket. More conservative therapeutic approaches seem to produce higher rates of relapse or failure of treatment<sup>2-18</sup>, and the best results relate to more aggressive approaches, with complete removal and implantation of new endocardial systems<sup>3-8</sup>, which is usually associated with high hospitalization rates and high costs<sup>3</sup>.</p>
      <p>Given the above, this study aimed to describe the scientific evidence about the biofilm formation and occurrence of infection associated with pacemakers in order to identify key recommendations for the prevention and control. It also aims to evaluate in the studies the incidence of infection and the microbial flora in pacemakers. Evidence-Based Practice was the theoretical reference which, in a medical problem, allows evaluating critically the production of scientific knowledge to support the decision<sup>19</sup>.</p>
      <p>
        <bold>Methods</bold>
      </p>
      <p>The method used was an integrative literature review, which is part of the Evidence-Based Practice, which allows the synthesis of evidence available on a defined issue, contributing to the deepening of knowledge on the subject investigated<sup>19</sup>.</p>
      <p>The articles select was based on the following question: <italic>What has been published on biofilm formation and infection related to cardiac pacemakers?</italic></p>
      <p>To search for articles, we used the data bases Medical Literature Analysis and Retrieval System (MEDLINE), Latin American and Caribbean Center on Health Sciences (LILACS), Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Cochrane Library, with Internet access. The descriptors were biofilms, pacemaker, artificial cardiac and infection, selected from the definitions in the Medical Subject Headings (MESH) and Descriptors in Health Sciences (DeCS) from the Virtual Library on Health (BVS).</p>
      <p>The studies selected were classified according to level of evidence: 01) systematic review or meta-analysis of randomized controlled trials; 02) at least one well-designed randomized controlled clinical trial; 03) well-designed clinical trials without randomization; 04) from well-designed cohort and case-controls; 05) systematic review of qualitative and descriptive studies; 06) single descriptive or qualitative study; and 07) opinion of authorities or reports of specialist committees<sup>20</sup>.</p>
      <p>The publications on the subject collected in full, in Portuguese, English and Spanish were included. The following exclusion criteria were established: structured studies in animal models and those related exclusively to the technique of implantation of pacemaker. Thus, through the careful reading of the title and abstract of the article in order to check consistency with the guiding question, 14 publications were collected, 05 in MEDLINE, two in LILACS, 05 in CINAHL and three in Cochrane Library. Two articles were found in two databases.</p>
      <p>
        <bold>Results and discussion</bold>
      </p>
      <p>We have found 14 publications since 1984, of which 06 were conducted in the USA, two in Spain, and only one in Austria, one in Brazil, one in Canada, one in Finland, one in France and one in Sweden. Accordingly, 12 were in English, one in Portuguese and one in Spanish. <xref ref-type="fig" rid="en_a18box01m-body2">Box 1</xref> shows the different designs of the studies and the levels of evidence. Thus, no systematic review study or meta-analysis of randomized controlled trials was evident, only two (14.3%) with level of evidence 02, 08 (57.1%) at level 04 (well-designed cohort and case-control) and 04 (28.6%) with levels 06 and 07.</p>
      <p content-type="asset">
        <fig id="en_a18box01m-body2">
          <graphic xlink:href="1678-4170-abc-97-05-e113-00018-gf01-en.jpg"/></fig>
      </p>
      <p><xref ref-type="fig" rid="en_a18box02m-body2">Box 2</xref> presented a synopsis of publications concerning the infections resulting from implants of pacemakers. It shows that the focus of attention of researchers permeated aspects related to microbiology, clinics, complications and treatment. Especially on the subject of biofilm in pacemakers, there were only two (14.3%) studies. It is speculated that the occurrence of biofilm formation is inevitable, but its confirmation in pacemakers involves removal of the implanted device, as well as advanced technology for scanning electron microscopy.</p>
      <p content-type="asset">
        <fig id="en_a18box02m-body2">
          <graphic xlink:href="1678-4170-abc-97-05-e113-00018-gf02-en.jpg"/></fig>
      </p>
      <p>With regard to aspects of microbial etiology, there was a concern focused on species and susceptibility profile or multidrug resistance of strains to antibiotics. The emphasis is on the appropriateness of antimicrobial therapy. Out of the total, only two (14.3%) studies were clinical trials of prophylactic antibiotics. This topic is still controversial among surgeons and infectious disease physicians, whether in the prophylaxis and/or therapy.</p>
      <p>It is noteworthy that the findings from this research do not determine the real situation of occurrence of infection associated with pacemakers, since the studies relate to a few situations. In this sense, data on the occurrence of biofilms in pacemakers are scarce, considering that this is a complex injury that is difficult to diagnose. Besides this, the population likely to use this device, in general, are the elderly with a history of arrhythmias, older age groups, and therefore with greater likelihood of infectious complications. Another aspect that makes it difficult to report the disease is that the appearance of symptoms of infection may be late, often not associated nor treated as a biofilm.</p>
      <p>However, the incidence of infections related to cardiac devices has been reported between 0.5% and 12%. In recent publications, the incidence is smaller than 5%<sup>8</sup> or close to 7<sup>21</sup>. Endocarditis associated with pacemaker lead is rare, but it is considered a serious infection. It was estimated that the incidence of endocarditis is 19.9%, however, this rate has probably been overestimated due to the absence of stringent criteria for diagnosis. Endocarditis associated with pacemaker lead was described in 16 patients in the transvenous removal group and 11 in the cardiopulmonary bypass group<sup>10</sup>.</p>
      <p>In the United States, each year about one million cases of nosocomial infections are associated with devices and about two thirds are caused by Staphylococcus aureus or Staphylococcus epidermidis<sup>12</sup>. Although approximately 1% of patients with endocardial pacemakers developed sepsis<sup>22</sup>. Infections associated with pacemakers are usually caused by <italic>S. epidermidis </italic>or <italic>S. aureus</italic><sup>4,9,12,24,26,27</sup>, and there was only one case of infection with <italic>Aspergillus spp</italic><sup>23</sup>. Greenspon et al<sup>9</sup> showed that <italic>S. aureus</italic> was the most common cause of endocarditis associated with pacemaker (53%), followed by <italic>S. epidermidis</italic> (22%) and streptococci (12%). Early infections occurred within 06 months and late infections in about 32 months. They also noted that the skin flora is the probable origin of endocarditis associated with pacemaker lead<sup>9</sup>. These data leads us to the studies on biofilm formation that justifies the prolonged time to the onset of the first symptoms of infection.</p>
      <p>In another study, <italic>S. epidermidis</italic> was the microorganism that caused most infections related to pacemakers<sup>24</sup>. The infection may involve any part of the pacemaker: the pocket, leads and the area of implantation of leads in the endocardium<sup>21</sup>. Moreover, biofilm formation by <italic>S. epidermidis</italic> may be influenced by the metal surface<sup>18</sup>.</p>
      <p>Infections associated with surgical implants are generally more difficult to treat because they require a long period of antibiotic therapy and repeated surgical procedures, with dramatic clinical and economic consequences. Mortality is higher among patients with cardiovascular implants and the cost of the device is a small fraction compared to the amount for the treatment of implant-related infection. The most important clinical goals in the treatment of these infections are to treat the infection, prevent recurrence, preserve function, set aside the risk of endocarditis and reduce the risk of death. Most often, these goals can be achieved by antimicrobial therapy and surgical intervention. And, perhaps, manufacturing and using cardiac pacemakers impregnated with antimicrobial agents. The diagnosis of infection from implant requires the presence of clinical manifestations and pathogens in surgical specimens, and blood cultures may be negative in cases of infection related to pacemakers, except in endocarditis associated<sup>12</sup>.</p>
      <p>A study of different treatment modalities of 38 patients with cardiac device-related infection, had 12 patients treated only with antibiotics, 19 had the device removed, reimplantation followed by antibiotics for short periods (10-14 days) and 07 patients received a longer period of 06 weeks of antimicrobial agent. The first group had recurrence of infection and in the other two, patients had the infection completely solved. This demonstrates the importance of removing the device in the treatment of infections<sup>21</sup>.</p>
      <p>According to Darouiche<sup>12</sup>, most implants contaminated with <italic>S. aureus</italic> or <italic>Candida</italic> spp. require surgical removal. The author justifies that it should be fully removed even if the contamination is only in the pacemaker pocket, because other parts of the device may also be contaminated. In the patients who respond to drug therapy, the implant should not be removed.Although removal of the implant is associated with the solution of the infection, it has to be authorized in patients at risk for complications during surgery and post-surgery<sup>12</sup>.</p>
      <p>As mentioned, treatment of infection associated with the system of artificial cardiac pacemaker is diverse. In cases with systemic sepsis or endocarditis, there is still a tendency to more aggressive approaches with prolonged intravenous antibiotic therapy (04 - 12 weeks), removal and complete replacement of endocardial systems.</p>
      <p>The result of the microbial culture is another aspect that defines the therapy, that is, conservative approach in cases of <italic>S. epidermidis</italic> or aggressive intervention for <italic>S. aureus</italic> have been recommended. Thus, we use the antibiotic therapy associated with the repositioning of the generator or the complete removal of endocardial systems and implantation of a new one, antibiotic therapy associated with local measures and irrigation, among others. All of these are coordinated with long periods of hospitalization, high costs and controversial results. The subpectoral implantation technique proved to be a feasible alternative in the treatment of pacemaker generator pocket infection, showing 100% effectiveness, a shorter hospital stay and a lower cost. However, further studies and follow-up are necessary for a definitive conclusion<sup>3-12</sup>.</p>
      <p>Scholars have shown that the synergy of different combinations of antibiotics against biofilms of <italic>S. epidermidis</italic> varied with the time of biofilm formation (06, 24, 48 hours). In general, all combinations of antibiotics were effective in new biofilms. The combination of vancomycin and rifampin had a bactericidal effect in 06 hours, and in old biofilms, the combinations with tetracycline were more effective. The difficulty of eradicating older biofilms was evident<sup>21,23</sup>.</p>
      <p>There are genes of biofilm formation mediation, such as genes of attachment (fbe and atlE) and adhesion (ica), which were observed in most strains of isolated <italic>S. epidermidis</italic> of patients with pacemaker. These data indicate an important role of adhesion genes in infections in pacemakers<sup>24</sup>.</p>
      <p>In the study by Marrie et al<sup>22</sup>, scanning electron microscopy revealed a different colonization in the pacemaker lead and the microorganism<italic> S. aureus</italic> was isolated at several sites. An extensive biofilm on the inner surface of the lead was then exposed and the external surface had a huge mass of biofilm with a population of bacterial cells adhered.All areas with cracks accumulated biofilm, which may justify the difficulty of action of therapy with antibiotics<sup>22</sup>. Therefore, in most cases, the removal of endocardial systems is indicated<sup>2-10,12,22</sup>.</p>
      <p>In a controversial manner, Bluhm et al<sup>4</sup> state that the use of a modern surgical technique combined with a meticulous aseptic practice excludes the use of systemic antibiotic prophylaxis in the implantation of pacemaker.</p>
      <p>There are reasons to expect that the development of pacemaker technologies has an impact on reducing rates of complications. Aspects such as the reduced size of the generator, increased quality and durability of leads, improved implantation techniques and aseptic procedures. However, dual-chamber stimulators, with the introduction of two leads, result in a longer implantation time, increasing the rate of complications. In 27-month follow-up after implantation, approximately 14% of patients had a complication. In most cases, complications from a clinical standpoint were low and with no deaths. In this study, infection rates were similar in patients receiving antibiotics (1.2%) and those who did not (1.7%), but there was no randomization of participants in the groups<sup>25</sup>. The benefit of administering antibiotics to reduce the risk of infection is still controversial.</p>
      <p>It is still worth noting the following facts:</p>
      <disp-quote>
        <p>&#149; The formation of extracellular polysaccharide by <italic>S. epidermidis</italic> was significantly higher in pacemakers than in intravenous catheters, which makes the threat by biofilm even higher<sup>26</sup>.</p>
        <p>&#149; The difficulties inherent in the safety of reprocessing devices also represents a high risk of contamination. There are reports of reprocessing of pacemakers that were removed from patients with infection<sup>2</sup>.</p>
        <p>&#149; Antibiotic prophylaxis, although controversial, seems to be promising in the prevention of infectious complications after pacemaker implantation<sup>8,10,27</sup>.</p>
        <p>&#149; In terms of sensitivity profile, researchers found that 67% of infections were associated with <italic>S. aureus</italic> resistant to methicillin, suggesting that this is an important pathogen of endocarditis associated with pacemaker lead<sup>9</sup>.</p>
        <p>&#149; A new technique for the management of pacemaker pocket infection without the removal of endocardial systems proved, in principle, a feasible low-cost alternative, however, we still need follow-up studies for a definitive conclusion<sup>3</sup>. This was the only study that proposed an alternative for the treatment of infection related to the pacemaker and has had good results.</p>
        <p>&#149; From complications related to pacemakers, 6.7% were early and 7.2% were late, and 3.1% related to implantation<sup>25</sup>. In the study by Maduro Maytin et al<sup>2</sup>, pacemaker pocket infection was a complication related to late re-interventions (0.4%).</p>
        <p>&#149; Regarding the biofilm, adhesion genes were almost always present in species recovered from patients with pacemakers, indicating the important role of these genes in the pathogenic mechanisms of pacemaker-related infection<sup>24</sup>. Differences in biofilm morphology may reflect the degree to which the fibrin and other materials become embedded in the developing biofilm<sup>26</sup>. The age of the biofilm may interfere with the action of antibiotics, because they are more effective in younger biofilms. They also predict that the resistance of microorganisms to antibiotics will make the treatment of cardiovascular infections harder<sup>21</sup>.</p>
      </disp-quote>
      <p>Systemic antibiotic prophylaxis significantly reduces the incidence of infectious complications after implantation of a permanent pacemaker<sup>8,10,27</sup>. In another study, there was no recurrence of infection after removal of the pacemaker lead; this is an effective procedure that can be applied even in patients with biofilms larger than one centimeter. Therefore, in pacemakers with biofilms larger than two centimeters in diameter, the recommendation was removal<sup>10</sup>. Maduro Maytin et al<sup>2 </sup>performed antibiotic prophylaxis within 24 hours before the implantation of a pacemaker and 05 days after, with a total of 0.4% of late infections in reoperations. In particular, researchers found that infections occurred in patients who did not receive antibiotic prophylaxis<sup>27</sup>. That said, there is strong evidence that the best approach for eradication of infection associated with biomaterial implants and reduction in mortality is the surgical intervention<sup>2-10,12,26</sup>. It seems consensus that all endocardial systems should be completely removed to eradicate infection from biofilm formation.</p>
      <p>
        <bold>Conclusion</bold>
      </p>
      <p>The biofilm is a current and little studied topic in the field of cardiology and even less when connected to the pacemaker. The conditions concerning the nature of the biomaterial, added to factors of risks to patients, such as extremes of age, immunocompromise due to multiple causes, underlying diseases, characterize the profile of the situation that deserves attention. In particular, additional research is needed to determine the current status of complications from the use of pacemakers in different patient populations, because studies examined individually signaled no statistically significant differences in the rates of infection.</p>
      <p>On the other hand, no study has explored the nature of biomaterials that compose the pacemakers and biofilm formation. Thus, the question is: will pacemakers impregnated with antimicrobial agents reduce or inhibit biofilm formation?</p>
      <p>In summary, the data analyzed show that the topic is of great importance and has been little studied, since in 24 years only 14 articles were published. With regard to professional nursing, even if it plays a key role in direct and/or indirect assistance to patients subject to the use of a pacemaker, both in implantation and in follow-up, especially in detecting signs and symptoms of infection, their participation was zero in these studies. Given the risk of infection associated with invasive procedures, it is worth noting the value of preventive measures.</p>
      <p>It also makes us think about the importance of measures of surveillance of infections, mainly in Brazil, a country marked by cultural diversity, socioeconomic inequalities, heterogeneous patterns of health care in terms of physical structure, type of patients and infections. Besides that, the Brazilian health system has historically faced the serious problem of social expansion, which is combined to a lack of human resources and inappropriate technology. Undoubtedly, these are fertile conditions for rising infection rates.</p>
      <p>
        <bold>Potential Conflict of Interest</bold>
      </p>
      <p>No potential conflict of interest relevant to this article was reported.</p>
      <p>
        <bold>Sources of Funding</bold>
      </p>
      <p>There were no external funding sources for this study.</p>
      <p>
        <bold>Study Association</bold>
      </p>
      <p>This study is not associated with any post-graduation program.</p>
      <p>
        <bold>References</bold>
      </p>
    </body>
  </sub-article>
  <sub-article article-type="translation" id="TRes" xml:lang="es">
    <front-stub>
      <article-categories/>
      <title-group>
        <article-title xml:lang="es">Biofilm en marcapaso artificial: &#191; ficci&#243;n o realidad?</article-title>
      </title-group>
      <abstract xml:lang="es">
        <p>La estimulaci&#243;n card&#237;aca artificial por medio de marcapaso card&#237;aco representa una de las alternativas m&#225;s promisorias en el tratamiento de las arritmias, sin embargo, puede ocasionar reacciones singulares o complejas, precoces o tard&#237;as. En este estudio, el objetivo fue describir las evidencias cient&#237;ficas sobre el riesgo de infecci&#243;n y formaci&#243;n de biofilm asociado al marcapaso card&#237;aco. Se trata de un estudio de revisi&#243;n integrante de la literatura. Se totalizaron 14 publicaciones clasificadas en tres categor&#237;as tem&#225;ticas: diagn&#243;stico (microbiol&#243;gico y/o cl&#237;nico), complicaciones y terap&#233;utica de las infecciones. Los Staphylococcus epidermidis y los Staphylococcus aureus fueron los microorganismos m&#225;s a menudo aislados. No se pudo determinar la incidencia de la infecci&#243;n asociada a los marcapasos, pues los estudios eran en general de prevalencia. En t&#233;rminos de terap&#233;utica se destac&#243; la retirada completa de los marcapasos, especialmente en los casos en que se sospechaba de biofilm. Todav&#237;a es algo controvertido el uso de la profilaxis antibi&#243;tica sist&#233;mica para la reducci&#243;n de la incidencia de la infecci&#243;n asociada al implante de marcapaso</p>
      </abstract>
      <kwd-group xml:lang="es">
        <kwd>Marcapaso artificial</kwd>
        <kwd>biofilms</kwd>
        <kwd>infecciones relacionadas con la pr&#243;tesis</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <p>
        <bold>ACTUALIZACI&#211;N CL&#205;NICA</bold>
      </p>
      <p>
        <fn id="enda-body3">
          <label>
            <bold>Biofilm en marcapaso artificial: &#191; ficci&#243;n o realidad?</bold>
          </label>
          <p>
            <bold>Ana Paula Azevedo Santos<sup>I</sup>; Evandro Watanabe<sup>II</sup>; Denise de Andrade<sup>I</sup></bold>
          </p>
        </fn>
      </p>
      <p><sup>I</sup>Escola de Enfermagem de Ribeir&#227;o Preto - Universidade de S&#227;o Paulo</p>
      <p><sup>II</sup>Faculdade de Odontologia de Ribeir&#227;o Preto - Universidade de S&#227;o Paulo, S&#227;o Paulo, SP, Brasil</p>
      <p>Correspondencia</p>
      <p>
        <bold>RESUMEN</bold>
      </p>
      <p>La estimulaci&#243;n card&#237;aca artificial por medio de marcapaso card&#237;aco representa una de las alternativas m&#225;s promisorias en el tratamiento de las arritmias, sin embargo, puede ocasionar reacciones singulares o complejas, precoces o tard&#237;as. En este estudio, el objetivo fue describir las evidencias cient&#237;ficas sobre el riesgo de infecci&#243;n y formaci&#243;n de biofilm asociado al marcapaso card&#237;aco. Se trata de un estudio de revisi&#243;n integrante de la literatura. Se totalizaron 14 publicaciones clasificadas en tres categor&#237;as tem&#225;ticas: diagn&#243;stico (microbiol&#243;gico y/o cl&#237;nico), complicaciones y terap&#233;utica de las infecciones. Los <italic>Staphylococcus epidermidis</italic> y los <italic>Staphylococcus aureus </italic>fueron los microorganismos m&#225;s a menudo aislados. No se pudo determinar la incidencia de la infecci&#243;n asociada a los marcapasos, pues los estudios eran en general de prevalencia. En t&#233;rminos de terap&#233;utica se destac&#243; la retirada completa de los marcapasos, especialmente en los casos en que se sospechaba de biofilm. Todav&#237;a es algo controvertido el uso de la profilaxis antibi&#243;tica sist&#233;mica para la reducci&#243;n de la incidencia de la infecci&#243;n asociada al implante de marcapaso.</p>
      <p><bold>Palabras clave:</bold> Marcapaso artificial/tendencias, biofilms, infecciones relacionadas con la pr&#243;tesis.</p>
      <p>
        <bold>Introducci&#243;n</bold>
      </p>
      <p>La estimulaci&#243;n card&#237;aca artificial fue introducida en la pr&#225;ctica cl&#237;nica en los a&#241;os 50 con el objetivo primordial de eliminar los s&#237;ntomas y de reducir la mortalidad de los pacientes con bloqueos atrioventriculares avanzados. El avance de la tecnolog&#237;a de fabricaci&#243;n y de implante del marcapaso, aliado al conocimiento electrofisiopatol&#243;gico de los disturbios de conducci&#243;n card&#237;aca, permiti&#243; un progreso consistente en la estimulaci&#243;n card&#237;aca artificial, extremadamente diversificada en su modo de funcionamiento, y con un alto nivel de fiabilidad, seguridad y siendo cada vez m&#225;s fisiol&#243;gica<sup>1</sup>.</p>
      <p>A pesar de que la cirug&#237;a de implante de marcapaso sea considerada de menor complejidad, es importante destacar que, por ser un procedimiento invasivo y un cuerpo extra&#241;o, pone al paciente en riesgo de adquirir diversas complicaciones, que pueden ser provenientes de fallos de los generadores, da&#241;o tisular o incluso de la t&#233;cnica quir&#250;rgica del implante<sup>2,3</sup>. La diversidad de arsenal y de conductas que existen, ha redundado en una mejor&#237;a en la t&#233;cnica quir&#250;rgica, sin embargo, tambi&#233;n existe una escasez de informaciones sobre las implicaciones y sobre los efectos de esas mejor&#237;as<sup>4</sup>.</p>
      <p>Una de las preocupaciones entre los profesionales es el riesgo de la formaci&#243;n de biofilm y consecuentemente, de infecci&#243;n. En las &#250;ltimas d&#233;cadas, el biofilm ha sido ampliamente responsabilizado por las infecciones nosocomiales, especialmente en los implantes de pr&#243;tesis, tubos, sondas y cat&#233;teres<sup>5-7</sup>. Se especula que la presencia de marcapasos favorezca la colonizaci&#243;n microbiana, contribuyendo en gran medida, con el desarrollo de biofilm, lo que tal vez pueda justificar la incidencia de endocarditis<sup>6-10</sup>.</p>
      <p>Es conveniente destacar que el biofilm est&#225; constituido por una comunidad estructurada de c&#233;lulas microbianas adheridas a una superficie s&#243;lida y envueltas en una matriz de sustancias polim&#233;ricas extracelulares. Esa asociaci&#243;n microbiana constituye una forma de protecci&#243;n contra su desarrollo, fomentando las relaciones simbi&#243;ticas y de tolerancia a los antimicrobianos. La literatura sobre el biofilm como factor de riesgo para la salud, ha venido avanzando a partir de la d&#233;cada de los 90<sup>5</sup>. La formaci&#243;n del biofilm envuelve una secuencia de eventos, como la adherencia inicial reversible de los microorganismos a la superficie del sustrato s&#243;lido, la multiplicaci&#243;n microbiana, la producci&#243;n de la matriz de sustancias polim&#233;ricas extracelulares y el desprendimiento de las c&#233;lulas s&#233;siles que, en forma planct&#243;nica, podr&#225;n ocasionar la infecci&#243;n o la formaci&#243;n de biofilm en otros locales.</p>
      <p>En el biofilm, existen microcolonias heterog&#233;neas, constituidas de c&#233;lulas microbianas de una (monomicrobiana), o m&#225;s especies (polimicrobiana), funcionalmente organizadas, donde los microorganismos est&#225;n protegidos de la acci&#243;n de los macr&#243;fagos y antibi&#243;ticos. Incluso el biofilm est&#225; compuesto por aproximadamente entre 10 y 25%, por microorganismos y entre 75 y 90%, por sustancias polim&#233;ricas extracelulares<sup>11</sup>.</p>
      <p>Una de las preocupaciones entre los estudiosos es el compromiso infeccioso que el biofilm puede desencadenar y, en muchos casos de implantes, la sustituci&#243;n del dispositivo es la alternativa m&#225;s indicada<sup>11</sup>. A eso sum&#233;mosle que es primordial la investigaci&#243;n de biofilm cuando la infecci&#243;n persiste<sup>12</sup>.</p>
      <p>Particularmente, el implante de marcapaso es un procedimiento caracterizado por un bajo &#237;ndice de complicaciones, sin embargo, la infecci&#243;n, principalmente la de la tienda de donde proviene el marcapaso, es una de las complicaciones m&#225;s comunes, con incidencias que var&#237;an entre 1-5%<sup>3-17</sup>. Pese a la baja incidencia, tales infecciones presentan una evoluci&#243;n preocupante y en la mayor&#237;a de los casos con una alta morbilidad y potencialmente fatales.</p>
      <p>Diversas conductas se han descrito para el tratamiento de la infecci&#243;n de la tienda de marcapaso. Los abordajes terap&#233;uticos m&#225;s conservadores parecen cursar con &#237;ndices m&#225;s elevados de recidiva o fracaso en el tratamiento<sup>2-18</sup>, siendo los mejores resultados relacionados con los abordajes m&#225;s agresivos, con la retirada completa y el implante de nuevos sistemas endoc&#225;rdicos<sup>3-8</sup>, conducta esa generalmente asociada a la alta permanencia hospitalaria y a los elevados costes<sup>3</sup>.</p>
      <p>Frente a lo ya dicho, preferimos concentrarnos en describir las evidencias cient&#237;ficas respecto de la formaci&#243;n del biofilm, y de la incidencia de infecci&#243;n asociadas a los marcapasos card&#237;acos, para identificar las principales recomendaciones de prevenci&#243;n y control. Tambi&#233;n se desea evaluar en los estudios la incidencia de la infecci&#243;n, y la microbiota presente en los marcapasos. Buscamos como referente te&#243;rico, la Pr&#225;ctica con Base en Evidencias que, frente a un problema cl&#237;nico, permite evaluar juiciosamente la producci&#243;n del conocimiento cient&#237;fico para fundamentar la toma de decisi&#243;n<sup>19</sup>.</p>
      <p>
        <bold>M&#233;todos</bold>
      </p>
      <p>El m&#233;todo utilizado fue la revisi&#243;n integrante de la literatura, que forma parte de la Pr&#225;ctica con Base en Evidencias, y que permite la s&#237;ntesis de las evidencias disponibles sobre una determinada cuesti&#243;n, aportando con la profundizaci&#243;n del conocimiento sobre el tema investigado<sup>19</sup>.</p>
      <p>La selecci&#243;n de los art&#237;culos se bas&#243; en el siguiente cuestionamiento:<italic> &#191;Qu&#233; es lo que se ha publicado sobre la formaci&#243;n de biofilm y la incidencia de infecci&#243;n relacionada con los marcapasos card&#237;acos?</italic></p>
      <p>Para la b&#250;squeda de los art&#237;culos, fueron utilizadas las bases de datos <italic>Medical Literature Analysis and Retrieval System</italic> (MEDLINE), Literatura Latinoamericana y Caribe&#241;a en Ciencias de la Salud (LILACS), <italic>Cumulative Index to Nursing and Allied Health Literature</italic> (CINAHL), y Biblioteca Cochrane, con acceso v&#237;a Internet. Los descriptores fueron biofilms (<italic>biofilms</italic>), marcapaso artificial card&#237;aco (<italic>pacemakers artificial cardiac),</italic> e infecci&#243;n (<italic>infection</italic>), seleccionados a partir de las definiciones del <italic>Medical Subject Headings</italic> (MESH), y de los Descriptores en Ciencias de la Salud (DeCs) de la Biblioteca Virtual en Salud (BVS).</p>
      <p>Los estudios seleccionados se clasificaron seg&#250;n el nivel de evidencia: 01) revisi&#243;n sistem&#225;tica o metan&#225;lisis de ensayos cl&#237;nicos randomizados controlados; 02) por lo menos un ensayo cl&#237;nico randomizado controlado bien delineado; 03) ensayos cl&#237;nicos bien delineados sin randomizaci&#243;n; 04) provenientes de cohorte y caso control bien delineados; 05) revisi&#243;n sistem&#225;tica de estudios descriptivos y cualitativos; 06) &#250;nico estudio descriptivo o cualitativo; y 07) opini&#243;n de autoridades o informes de comit&#233;s de expertos<sup>20</sup>.</p>
      <p>Fueron incluidas las publicaciones sobre la tem&#225;tica obtenidas integralmente en los idiomas portugu&#233;s, ingl&#233;s y espa&#241;ol. Como criterios de exclusi&#243;n se establecieron: estudios estructurados en un modelo animal y los referentes exclusivamente a la t&#233;cnica de implante de marcapaso. Mediante la lectura juiciosa del t&#237;tulo y del resumen del art&#237;culo, para verificar la adecuaci&#243;n con la cuesti&#243;n que guiaba el trabajo, se totalizaron 14 publicaciones, cinco en el MEDLINE, dos en el LILACS, cinco en el CINAHL y tres en la Biblioteca Cochrane. Un mismo art&#237;culo fue identificado en dos bases de datos.</p>
      <p>
        <bold>Resultados y discusi&#243;n</bold>
      </p>
      <p>Se completaron 14 publicaciones a partir de 1984, siendo seis de ellas realizadas en los Estados Unidos, dos en Espa&#241;a, y apenas una en Austria, una en Brasil, una en Canad&#225;, una en Finlandia, una en Francia y una en Suecia. En ese sentido, 12 eran en ingl&#233;s, una en portugu&#233;s y una en espa&#241;ol. En el <xref ref-type="fig" rid="es_a18qd01m-body3">Cuadro 1</xref>, aparecen desglosados los diferentes perfiles de los estudios y los niveles de evidencias. Por lo tanto, ning&#250;n estudio de revisi&#243;n sistem&#225;tica o metan&#225;lisis de ensayos cl&#237;nicos randomizados controlados fue evidenciado, apenas dos (14,3%), con un nivel de evidencia 02, 08 (57,1%) con un nivel 04 (cohorte y caso control bien perfilados), y 04 (28,6%) con niveles 06 y 07.</p>
      <p content-type="asset">
        <fig id="es_a18qd01m-body3">
          <graphic xlink:href="1678-4170-abc-97-05-e113-00018-gf01-es.jpg"/></fig>
      </p>
      <p>El <xref ref-type="fig" rid="es_a18qd02m-body3">Cuadro 2</xref> es una sinopsis de las publicaciones acerca de las infecciones provenientes de los implantes de marcapasos card&#237;acos, y revel&#243; que el foco de atenci&#243;n de los investigadores estuvo centrado en los aspectos relacionados con la microbiolog&#237;a, la cl&#237;nica, las complicaciones y la terap&#233;utica. Especialmente sobre la tem&#225;tica de biofilm en marcapasos, se verificaron solamente dos trabajos (14,3%). Pensamos que la incidencia de la formaci&#243;n de biofilm es algo inevitable, ya su confirmaci&#243;n en marcapasos envuelve la retirada del artefacto implantado, como tambi&#233;n la tecnolog&#237;a avanzada de microscop&#237;a electr&#243;nica de barrido.</p>
      <p content-type="asset">
        <fig id="es_a18qd02m-body3">
          <graphic xlink:href="1678-4170-abc-97-05-e113-00018-gf02-es.jpg"/></fig>
      </p>
      <p>En lo concerniente a los aspectos de la etiolog&#237;a microbiana, se verific&#243; una preocupaci&#243;n concentrada en la especie y en el perfil de sensibilidad o multirresistencia de las cepas a los antimicrobianos. El &#233;nfasis es la adecuaci&#243;n de la terap&#233;utica antimicrobiana. Del total, apenas dos estudios (14,3%), fueron ensayos cl&#237;nicos sobre antibioticoterapia profil&#225;ctica, tema que todav&#237;a causa pol&#233;mica entre los cirujanos e infect&#243;logos, ya sea en la profilaxis y/o en la terap&#233;utica.</p>
      <p>Es bueno destacar que los resultados de esta investigaci&#243;n no permiten determinar la real situaci&#243;n de la incidencia de infecci&#243;n asociada a los marcapasos, pues los estudios se reportan a situaciones aisladas. En ese sentido, los datos sobre la incidencia de biofilm en marcapasos son escasos, ya que se trata de un motivo complejo y de dif&#237;cil diagn&#243;stico. A&#241;adimos a eso que la poblaci&#243;n propensa al uso de ese dispositivo en general, son ancianos con antecedentes de arritmias, una franja etaria elevada y por tanto, con mayor probabilidad de complicaciones infecciosas. Otro aspecto que dificulta la notificaci&#243;n es que el aparecimiento de los s&#237;ntomas de infecci&#243;n puede ser tard&#237;o, y en muchas ocasiones no se asocia ni se trata como biofilm.</p>
      <p>Sin embargo, la incidencia de infecciones relacionadas con dispositivos card&#237;acos fue relatada entre un 0,5% y un 12%. En recientes publicaciones, la incidencia es menor que 5%<sup>8 </sup>o se aproxima de 7%<sup>21</sup>. La endocarditis asociada al electrodo del marcapaso es rara, pero su aparici&#243;n est&#225; considerada como siendo una infecci&#243;n grave. Se ha estimado que su incidencia entre endocarditis es del 19,9% sin embargo, esa cifra probablemente haya sido supervalorada por la ausencia de rigurosos criterios de diagn&#243;stico. La endocarditis asociada al electrodo del marcapaso se describi&#243; en 16 pacientes del grupo de retirada transvenosa y en 11 en el grupo de circulaci&#243;n extracorp&#243;rea<sup>10</sup>.</p>
      <p>En los Estados Unidos, anualmente cerca de un mill&#243;n de casos de infecciones nosocomiales est&#225; asociada a dispositivos, y cerca de dos tercios son causados por <italic>Staphylococcus aureus</italic> o <italic>Staphylococcus epidermidis</italic><sup>12</sup>. Tambi&#233;n, aproximadamente, el 1% de los pacientes con estimuladores endocardiacos ha desarrollado sepsis<sup>22</sup>. Las infecciones asociadas a marcapasos generalmente las causan <italic>S. epidermidis </italic>o <italic>S. aureus</italic><sup>4,9,12,24,26,27</sup>, habiendo solamente un caso de infecci&#243;n por <italic>Aspergillus</italic> spp.<sup>23</sup>. Greenspon et al<sup>9</sup> demostraron que <italic>S. aureus</italic> fue la causa m&#225;s com&#250;n de endocarditis asociada al marcapaso (53%), seguido por <italic>S. epidermidis </italic>(22%) y estreptococos (12%). Las infecciones precoces se dieron en el plazo de 06 meses y las tard&#237;as en aproximadamente 32 meses. Tambi&#233;n destacaron que la microbiota de la piel es probablemente el origen de la endocarditis asociada al electrodo del marcapaso<sup>9</sup>. Esos datos nos remiten a los estudios sobre la formaci&#243;n de biofilm que justifica el tiempo prolongado para el aparecimiento de los primeros s&#237;ntomas de la infecci&#243;n.</p>
      <p>En otro estudio, <italic>S. epidermidis</italic> fue el microorganismo que caus&#243; m&#225;s infecciones relacionadas con los marcapasos<sup>24</sup>. Siendo que la infecci&#243;n puede involucrar a cualquier parte del marcapaso: la bolsa, los electrodos y el &#225;rea de implante de los electrodos en el endocardio<sup>21</sup>. Adem&#225;s, la formaci&#243;n del biofilm por <italic>S. epidermidis </italic>puede recibir la influencia de la superficie del metal<sup>18</sup>.</p>
      <p>Las infecciones asociadas a implantes quir&#250;rgicos son generalmente m&#225;s dif&#237;ciles de tratar, porque requieren un largo per&#237;odo de terapia con antibi&#243;ticos y repetidos procedimientos quir&#250;rgicos, con dr&#225;sticas consecuencias cl&#237;nicas y econ&#243;micas. La mortalidad es m&#225;s elevada entre los pacientes con implantes cardiovasculares y el coste del dispositivo constituye una peque&#241;a fracci&#243;n con relaci&#243;n al monto destinado al tratamiento de la infecci&#243;n relacionada con el implante. Los objetivos cl&#237;nicos m&#225;s importantes en el tratamiento de esas infecciones son: tratar la infecci&#243;n, evitar la reincidencia, preservar la funci&#243;n, anular el riesgo de endocarditis y reducir el riesgo de muerte. En su mayor&#237;a, esos objetivos pueden alcanzarse por la terapia antimicrobiana y la intervenci&#243;n quir&#250;rgica, y tal vez, avanzar en la confecci&#243;n y en la utilizaci&#243;n de marcapasos card&#237;acos impregnados con agentes antimicrobianos. El diagn&#243;stico de infecci&#243;n por el implante exige la presencia de manifestaciones cl&#237;nicas y de agentes pat&#243;genos en muestras quir&#250;rgicas, siendo que cultivos de sangre pueden ser negativos en casos de infecci&#243;n relacionada con marcapasos, salvo en la endocarditis asociada<sup>12</sup>.</p>
      <p>En un estudio sobre las diferentes modalidades de tratamiento de 38 pacientes con infecci&#243;n relacionada con el dispositivo card&#237;aco, se obtuvo 12 pacientes tratados solamente con antibi&#243;ticos, 19 a los que se les retir&#243; el dispositivo, un reimplante seguido por cortos per&#237;odos de antibi&#243;ticos (10-14 d&#237;as), y 07 pacientes que recibieron un per&#237;odo mayor de 06 semanas de antimicrobiano. En el primer grupo, hubo una reincidencia de la infecci&#243;n y en los otros dos, los pacientes tuvieron la infecci&#243;n completamente solucionada. Eso demuestra la importancia de la retirada del dispositivo en el tratamiento de esas infecciones<sup>21</sup>.</p>
      <p>De acuerdo con Darouiche<sup>12</sup>, la mayor&#237;a de los implantes contaminados por <italic>S. aureus</italic> o <italic>Candida</italic> spp. necesitan la retirada quir&#250;rgica. El autor justifica que est&#225; indicada la retirada total aunque la contaminaci&#243;n est&#233; solamente en la bolsa del marcapaso, porque las otras partes del dispositivo tambi&#233;n pueden estar contaminadas. Ya en los pacientes que responden a la terapia medicamentosa, el implante no debe ser retirado. Aunque la retirada del implante est&#233; asociada a la soluci&#243;n de la infecci&#243;n, tiene que estar autorizada en los pacientes que presentan un riesgo de complicaciones intraoperatorias y postoperatorias<sup>12</sup>.</p>
      <p>Como ya fue mencionado, la terap&#233;utica de la infecci&#243;n asociada al sistema de marcapaso card&#237;aco artificial es diversa. En los casos de compromiso sist&#233;mico con sepsis o endocarditis, todav&#237;a existe una tendencia a los abordajes m&#225;s agresivos con antibioticoterapia endovenosa prolongada (04 - 12 semanas), y la retirada y el cambio completo de los sistemas endoc&#225;rdicos.</p>
      <p>El resultado del cultivo microbiano es otro aspecto que reordena la terap&#233;utica, o sea, reordena el abordaje conservador en los casos de <italic>S. epidermidis</italic> o intervenci&#243;n agresiva para el <italic>S. aureus </italic>que han sido los aconsejados. Por tanto, se usa la antibioticoterapia asociada al reposicionamiento del generador o a la retirada completa de los sistemas endoc&#225;rdicos e implante de un nuevo marcapaso, antibioticoterapia asociada a medidas locales e irrigaci&#243;n, entre otras. Todas dirigidas a largos per&#237;odos de ingreso, altos costes y resultados controvertidos. La t&#233;cnica de implante subpectoral se ha mostrado como una alternativa viable para el tratamiento de la infecci&#243;n de la tienda proveedora del marcapaso, presentando un 100% de eficacia, un corto per&#237;odo de ingreso y un bajo coste. Sin embargo, todav&#237;a se hacen necesarios estudios y seguimientos para arribar a una conclusi&#243;n definitiva<sup>3-12</sup>.</p>
      <p>Los estudiosos revelaron que la sinergia de diferentes combinaciones de antibi&#243;ticos contra biofilms de<italic> S. epidermidis</italic> vari&#243; con el tiempo de formaci&#243;n de esos biofilms (06, 24, 48 horas). En general, todas las combinaciones de antibi&#243;ticos fueron eficaces en biofilms nuevos. La combinaci&#243;n entre vancomicina y rifampicina surti&#243; un efecto bactericida en 06 horas; y en los biofilms antiguos, las combinaciones con tetraciclina fueron m&#225;s eficaces. Qued&#243; evidente la dificultad de erradicar los biofilms m&#225;s antiguos<sup>21,23</sup>.</p>
      <p>Existen genes de mediaci&#243;n de formaci&#243;n de biofilm, tales como genes de anexo (fbe y atlE) y adherencia (ica), que se observaron en la mayor&#237;a de las cepas de <italic>S. epidermidis</italic> aisladas de pacientes con marcapaso. Esos datos indican un papel importante de los genes de adherencia en las infecciones en marcapasos<sup>24</sup>.</p>
      <p>En el estudio de Marrie et al<sup>22</sup>,la microscop&#237;a electr&#243;nica de barrido arroj&#243; una colonizaci&#243;n diferente en el electrodo del marcapaso, y el microorganismo <italic>S. aureus</italic> fue aislado en varios sitios. Un extenso biofilm en la superficie interna del electrodo se observ&#243; y en la superficie externa hab&#237;a una enorme masa de biofilm con una poblaci&#243;n de c&#233;lulas bacterianas adheridas.Todas las &#225;reas con fisuras acumularon biofilm, lo que tal vez justifique la dificultad de acci&#243;n de la terapia con antibi&#243;ticos<sup>22</sup>. Por eso, en la mayor&#237;a de los casos, est&#225; indicada la retirada de los sistemas endoc&#225;rdicos<sup>2-10,12,22</sup>.</p>
      <p>Controvertidamente,Bluhm et al<sup>4</sup> explican que el uso de la t&#233;cnica quir&#250;rgica moderna articulada con la meticulosa pr&#225;ctica de la asepsia, excluye el uso de la profilaxis antibi&#243;tica sist&#233;mica en el implante de marcapaso.</p>
      <p>Existen motivos para esperar que la evoluci&#243;n de la tecnolog&#237;a de marcapasos impacte en la reducci&#243;n de las tasas de complicaciones. Aumentaron los aspectos como el reducido tama&#241;o del generador, la calidad y la durabilidad de los electrodos; y las t&#233;cnicas de implante y de asepsia fueron perfeccionadas. Sin embargo, los estimuladores implantados del tipo doble c&#225;mara, con la introducci&#243;n de dos electrodos, conllevan a un tiempo de implante m&#225;s largo, aumentando las tasas de complicaciones. En el seguimiento de 27 meses despu&#233;s del implante, aproximadamente un 14% de los pacientes sufrieron una complicaci&#243;n. En la mayor&#237;a de los casos, las complicaciones desde el punto de vista cl&#237;nico eran bajas y sin muertes. En este estudio, las tasas de infecci&#243;n fueron parecidas entre los pacientes que recibieron antibi&#243;ticos (1,2%) y los que no los recibieron (1,7%), sin embargo, no hubo aleatoriedad de los participantes en los grupos<sup>25</sup>. El beneficio de la administraci&#243;n de antibi&#243;ticos para reducir el riesgo de infecciones todav&#237;a causa pol&#233;mica.</p>
      <p>Tambi&#233;n nos parece oportuno destacar los siguientes hechos:</p>
      <disp-quote>
        <p>&#149; La formaci&#243;n de polisac&#225;rido extracelular por <italic>S. epidermidis </italic>fue considerablemente mayor en marcapasos que en los cat&#233;teres intravenosos, lo que refuerza m&#225;s todav&#237;a la amenaza por biofilm<sup>26</sup>. </p>
        <p>&#149; Las dificultades inherentes a la seguridad del reprocesamiento de art&#237;culos tambi&#233;n representa un elevado riesgo de contaminaci&#243;n. Hay relatos de reprocesamiento de marcapasos retirados de pacientes que estaban infectados<sup>2</sup>.</p>
        <p>&#149; La profilaxis antibi&#243;tica, aunque sea algo controvertido, parece promisoria en la prevenci&#243;n de las complicaciones infecciosas despu&#233;s del implante de marcapaso<sup>8,10,27</sup>.&gt;</p>
        <p>&#149; En t&#233;rminos de perfil de sensibilidad, los estudiosos verificaron que un 67% de las infecciones estaban asociadas al <italic>S. aureus</italic> resistente a la meticilina, sugiriendo que ese es un agente patog&#233;nico importante para la endocarditis asociada al electrodo del marcapaso<sup>9</sup>.</p>
        <p>&#149; Una nueva t&#233;cnica para el manejo de la infecci&#243;n de la tienda de donde proviene el marcapaso sin la retirada de los sistemas endoc&#225;rdicos, pareci&#243; ser en principio una alternativa viable y con un bajo coste, sin embargo, todav&#237;a son necesarios estudios de seguimiento para una conclusi&#243;n definitiva<sup>3</sup>. Ese fue el &#250;nico estudio que propuso una alternativa para el tratamiento de la infecci&#243;n relacionada con el marcapaso y que obtuvo buenos resultados.</p>
        <p>&#149; De las complicaciones relacionadas con el marcapaso 6,7% fueron precoces y un 7,2% tard&#237;as, siendo un 3,1% relacionadas con el implante<sup>25</sup>. En el estudio de Maduro Maytin et al<sup>2</sup>, la infecci&#243;n en la bolsa del marcapaso fue una complicaci&#243;n relacionada con las reintervenciones tard&#237;as (0,4%).</p>
        <p>&#149; Con relaci&#243;n al biofilm, los genes de adherencia estuvieron casi siempre presentes en especies recuperadas de pacientes con marcapaso, indicando el papel importante de esos genes en los mecanismos de patogenicidad de la infecci&#243;n relacionadas con el marcapaso<sup>24</sup>. Las diferencias de morfolog&#237;as del biofilm pueden reflejarse en el grado en que la fibrina y otros materiales se incorporan al biofilm en desarrollo<sup>26</sup>. La edad del biofilm puede interferir en la acci&#243;n del antibi&#243;tico, pues son m&#225;s eficaces en los biofilms m&#225;s j&#243;venes. Y todav&#237;a se vaticina que la resistencia de los microorganismos a los antibi&#243;ticos har&#225; con que el tratamiento de las infecciones cardiovasculares sea m&#225;s dif&#237;cil<sup>21</sup>.</p>
      </disp-quote>
      <p>La profilaxis antibi&#243;tica sist&#233;mica reduce significativamente la incidencia de complicaciones infecciosas despu&#233;s del implante de marcapaso permanente<sup>8,10,27</sup>. En otra investigaci&#243;n, no se registr&#243; recurrencia de infecci&#243;n despu&#233;s de la retirada del electrodo del marcapaso, siendo un procedimiento eficaz que puede ser aplicado incluso en pacientes que demuestran biofilms mayores que un cent&#237;metro. Por tanto, en el marcapaso con biofilms mayores que dos cent&#237;metros de di&#225;metro, la recomendaci&#243;n fue la retirada<sup>10</sup>. Maduro Maytin et al<sup>2</sup> realizaron una profilaxis con antibi&#243;ticos en 24 horas antes del implante del marcapaso y 05 d&#237;as despu&#233;s con un total de 0,4% de infecciones tard&#237;as en las reintervenciones. En ese caso en particular, los investigadores observaron que las infecciones se dieron en los pacientes que no recibieron profilaxis con antibi&#243;ticos<sup>27</sup>. Por lo tanto, las evidencias son contundentes en el sentido de que el mejor abordaje en la erradicaci&#243;n de la infecci&#243;n asociada a implantes de biomateriales y a la disminuci&#243;n de la mortalidad es la intervenci&#243;n quir&#250;rgica<sup>2-10,12,26</sup>. Vemos como un consenso, el hecho de que todos los sistemas endoc&#225;rdicos deben ser totalmente retirados para erradicar definitivamente la infecci&#243;n por formaci&#243;n de biofilm.</p>
      <p>
        <bold>Conclusi&#243;n</bold>
      </p>
      <p>El biofilm es un tema actual y que todav&#237;a no se ha estudiado mucho en el &#225;rea de la cardiolog&#237;a, y mucho menos cuando se relaciona con el marcapaso. Las condiciones relativas a la naturaleza del biomaterial, a&#241;adidas a los factores de riesgos inherentes a los pacientes, como edad extrema, inmunocompromiso de causas variadas y las enfermedades de base, caracterizan el perfil de la situaci&#243;n que merece nuestra atenci&#243;n. En ese caso, las investigaciones adicionales son necesarias para determinar la situaci&#243;n actual de las complicaciones provenientes del uso de marcapasos en diferentes poblaciones de pacientes, considerando que los estudios analizados individualmente, no resaltaron las diferencias estad&#237;sticamente significativas con relaci&#243;n a las tasas de infecci&#243;n.</p>
      <p>Por otra parte, ning&#250;n estudio explor&#243; la naturaleza de los biomateriales con los que est&#225;n fabricados los marcapasos y la formaci&#243;n del biofilm. Por lo tanto, nos cuestionamos lo siguiente: &#191;es posible que marcapasos impregnados con antimicrobianos pudiesen reducir o inhibir la formaci&#243;n de biofilm?</p>
      <p>En resumen, los datos analizados reflejan que el tema es de gran importancia y ha sido poco estudiado, ya que en 24 a&#241;os solamente 14 art&#237;culos fueron publicados. Con relaci&#243;n al profesional de enfermer&#237;a, aunque tenga un rol fundamental en la asistencia directa y/o indirecta al paciente que est&#225; sujeto al uso del marcapaso, tanto en el implante como en el seguimiento, especialmente en la detecci&#243;n de se&#241;ales y s&#237;ntomas de infecci&#243;n, su participaci&#243;n fue nula en esos estudios. Frente al riesgo de infecci&#243;n asociada a procedimientos invasivos, vale resaltar el valor de las medidas de prevenci&#243;n.</p>
      <p>Dejamos aqu&#237; tambi&#233;n una reflexi&#243;n sobre la importancia de las medidas de vigilancia epidemiol&#243;gica de las infecciones, principalmente en Brasil, que es un pa&#237;s que se destaca por su diversidad cultural, por las desigualdades socioecon&#243;micas, por est&#225;ndares heterog&#233;neos de atenci&#243;n en la salud, en t&#233;rminos de estructura f&#237;sica, tipo de clientela y aparecimiento de infecci&#243;n. A eso hay que a&#241;adir que, hist&#243;ricamente, el sistema de salud nacional enfrenta el grave problema de la ampliaci&#243;n social, unido a la falta cuantitativa de recursos humanos y a la inadecuada obtenci&#243;n de la tecnolog&#237;a. Sin duda, &#233;sas son condiciones muy propensas para la elevaci&#243;n de los &#237;ndices de infecci&#243;n.</p>
      <p>
        <bold>Potencial Conflicto de Intereses</bold>
      </p>
      <p>Declaro no haber conflicto de intereses pertinentes.</p>
      <p>
        <bold>Fuentes de Financiaci&#243;n</bold>
      </p>
      <p>El presente estudio no tuve fuentes de financiaci&#243;n externas.</p>
      <p>
        <bold>Vinculaci&#243;n Acad&#233;mica</bold>
      </p>
      <p>No hay vinculaci&#243;n de este estudio a programas de postgrado.</p>
      <p>
        <bold>Referencias</bold>
      </p>
    </body>
  </sub-article>
</article>
