Blood flow evaluation during extracorporeal circulation in pediatrics.

Abstract

Introduction and Objective: Perfusion in adult patients has been deeply studied and little clinical evidence in the pediatric perfusion area. This study evaluated blood flow during pediatric cardiopulmonary bypass.  Methods: One hundred eleven pediatric perfusions and its arterial and venous blood gases report were analyzed at the initial period from 245 a total of congenital heart disease surgery with cardiopulmonary bypass. t Student test and descriptive statics were used. Results: Blood Flow 2,76 ± 0,35 l/min/m² (cardiac index) and 128 ± 26 cc/kg/min (weight). S_vO₂ 72 ±10 %, ETO₂ 0,27 ± 0,10, DO_2i 379± 83 and VO_2i 116 ± 41 ml/min/m². VO₂ corresponded 27,5-27,8% from DO_2. Oxygen delivery-consumption ratio was 3,2:1.  ETO₂ ˃ 0,30 was related to a VO_2i ˃ 151 ± 37,41 ml/min/m², lactate level at the beginning of CPB was 2,60 ± 1,03 and at the ICU arrival 3,03 ± 1,72 (mmol/l), veno-arterial PCO₂ difference was 8,6 ± 5,5 mmHg. 8 patients (7,2%) presented lactate level ˃ 4 mmol/l at the beginning and 28 patients (25%) at the ICU arrival. Conclusions: Blood Flow at the beginning of CPB matches the initial goal stablished by our institutional protocol. With cardiac index ˃ 2,4 l/min/m² was obtained S_vO₂ ˂70%. At low DO₂ level, blood lactate value, elevates. High oxygen consumption did not reflect high lactate level, but an ETO₂ ˃ 0,30. Lactate values between 1 and 4 mmol/l are expected at the beginning of CPB. Hyperlactatemia at ICU arrival predicts adverse outcomes and dead. Veno-arterial PCO₂ difference ˃ 6 mmHg was not reflection of low blood flow nor high lactate level.