Mechanisms underlying gas exchange alterations in an experimental model of pulmonary embolism

dc.creatorFerreira, J.H.T.
dc.creatorTerzi, R.G.G.
dc.creatorPaschoal, I.A.
dc.creatorSilva, W.A.
dc.creatorMoraes, A.C.
dc.creatorMoreira, M.M.
dc.date2006-09-01
dc.date2014-07-18T13:28:43Z
dc.date2015-11-26T11:56:33Z
dc.date2014-07-18T13:28:43Z
dc.date2015-11-26T11:56:33Z
dc.date.accessioned2018-03-28T20:59:28Z
dc.date.available2018-03-28T20:59:28Z
dc.identifierBrazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 39, n. 9, p. 1197-1204, 2006.
dc.identifier0100-879X
dc.identifierS0100-879X2006000900007
dc.identifierhttp://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000900007
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/31227
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/31227
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1238535
dc.descriptionThe aim of the present study was to determine the ventilation/perfusion ratio that contributes to hypoxemia in pulmonary embolism by analyzing blood gases and volumetric capnography in a model of experimental acute pulmonary embolism. Pulmonary embolization with autologous blood clots was induced in seven pigs weighing 24.00 ± 0.6 kg, anesthetized and mechanically ventilated. Significant changes occurred from baseline to 20 min after embolization, such as reduction in oxygen partial pressures in arterial blood (from 87.71 ± 8.64 to 39.14 ± 6.77 mmHg) and alveolar air (from 92.97 ± 2.14 to 63.91 ± 8.27 mmHg). The effective alveolar ventilation exhibited a significant reduction (from 199.62 ± 42.01 to 84.34 ± 44.13) consistent with the fall in alveolar gas volume that effectively participated in gas exchange. The relation between the alveolar ventilation that effectively participated in gas exchange and cardiac output (V Aeff/Q ratio) also presented a significant reduction after embolization (from 0.96 ± 0.34 to 0.33 ± 0.17 fraction). The carbon dioxide partial pressure increased significantly in arterial blood (from 37.51 ± 1.71 to 60.76 ± 6.62 mmHg), but decreased significantly in exhaled air at the end of the respiratory cycle (from 35.57 ± 1.22 to 23.15 ± 8.24 mmHg). Exhaled air at the end of the respiratory cycle returned to baseline values 40 min after embolism. The arterial to alveolar carbon dioxide gradient increased significantly (from 1.94 ± 1.36 to 37.61 ± 12.79 mmHg), as also did the calculated alveolar (from 56.38 ± 22.47 to 178.09 ± 37.46 mL) and physiological (from 0.37 ± 0.05 to 0.75 ± 0.10 fraction) dead spaces. Based on our data, we conclude that the severe arterial hypoxemia observed in this experimental model may be attributed to the reduction of the V Aeff/Q ratio. We were also able to demonstrate that V Aeff/Q progressively improves after embolization, a fact attributed to the alveolar ventilation redistribution induced by hypocapnic bronchoconstriction.
dc.description1197
dc.description1204
dc.languageen
dc.publisherAssociação Brasileira de Divulgação Científica
dc.relationBrazilian Journal of Medical and Biological Research
dc.rightsaberto
dc.sourceSciELO
dc.subjectEffective alveolar ventilation
dc.subjectMismatching ventilation/ perfusion
dc.subjectPulmonary gas exchange
dc.titleMechanisms underlying gas exchange alterations in an experimental model of pulmonary embolism
dc.typeArtículos de revistas


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