Alterações hemodinâmicas, respiratórias e metabólicas agudas após o contato do sangue com o circuito extracorpóreo da ECMO: estudo experimental

Abstract

Rev Bras Ter Intensiva. 2012; 24(2):137-142 acute hemodynamic, respiratory and metabolic alterations after blood contact with a volume priming and extracorporeal life support circuit: an experimental study Alterações hemodinâmicas respiratórias e metabólicas agudas após o contato do sangue com o circuito extracorpóreo da ECMO: estudo experimental ORIGINAL ARTICLE INTROduCTIONExtracorporeal membrane oxygenation (ECMO) has been used to support patients with severe respiratory and/or cardiovascular failure. (1) Despite increasing clinical experience and success, (2)(3)(4)(5) there are currently few reports in the literature about the physiology and about acute patients' experienced with ECMO use. (6) In animal studies, the use of polypropylene ECMO is associated with an acute elevation of plasmatic interleukins and with intestinal and pulmonary edema. (7) Accordingly, gut barrier dysfunction associated with polypropylene ECMO use can be an important contributor to ECMOrelated systemic inflammation. (8) In human beings, respiratory support using polymethylpentene ECMO membranes is also associated with early, new, radiographic pulmonary infiltrates, a phenomenon known as whiteout. (9) AbsTRACT Objective: To investigate the hemodynamic, respiratory and metabolic impact of blood contact with a priming volume and extracorporeal membrane oxygenation circuit, before the initiation of oxygenation and ventilation Methods: Five animals were instrumented and submitted to extracorporeal membrane oxygenation. Data were collected at the baseline and 30 minutes after starting extracorporeal circulation, without membrane ventilatory (sweeper) flow.Results: After starting extracorporeal membrane oxygenation, there was a non-significant elevation in pulmonary vascular resistance from 235 (178,303) to 379 (353,508) dyn.seg.(cm 5 ) -1 (P=0.065), associated with an elevation in the alveolar arterial oxygen gradient from 235 (178,303) to 379 (353,508) mmHg (P=0.063). We also observed a reduction in the left ventricle stroke work from 102 (94,105) to 78 (71,87) (mL.mmHg)/beat (P=0.064), in addition to a reduction in cardiac output from 7.2 (6.8,7.6) to 5.9 (5.8,6.3) L/min (P=0.188). The right ventricle stroke work was counterbalanced between the pulmonary vascular resistance increment and the cardiac output reduction, maintaining a similar value. Conclusions:We presented an experimental model that is feasible and safe. Blood contact with the priming volume and extracorporeal membrane oxygenation circuit resulted in nonsignificant systemic or metabolic changes.

Avaliação dos parâmetros gasométricos dos traumatizados durante o atendimento pré-hospitalar móvel

“…Although there was a higher number of patients in the group of survivors, this may reduce the value of our results. However, even with the theoretical disadvantage of the non-survivors, there was a lower incidence of blood gas alterations in this group 4,24 .…”