The relationship between metabolic acidosis, lactate, the lactate:pyruvate ratio, and outcome, in children with post-operative cardiogenic and septic shock

Abstract

Measures of the severity of metabolic acidosis (base excess) and of the severity of the underlying acid-base derangements (levels of lactate, chloride, albumin, and strong ion gap) have been used to differentiate survivors from nonsurvivors in various types of adult critical illness, including states of severe hamodynamic compromise following cardiac surgery on cardiopulmonary bypass (CPB) and in septic shock. prognostic studies of acid-base data for critically ill children in the settings of post-operative cardiogenci shock and septic shock are relatively scarce. It has been suggested that hyperchloraemia migh be a benign phenomenon that should not prompt escalation of therapy. Although it is recognised that hypoalbuminaemia is associated with adverse outcome, and obscrues the extent of underlying metabolic acidosis, the significance of 'unmeasured' anions estimated from the strong ion gap remains controversial. It has been suggested that the admission lactate level is strongly predictive of paediatric intensive care unit (PICU) outcome in both shock states, but it is not known whether calculation of the lactate: pyruvate ratio would add prognostic value in children with either post-operative cardiogenic, or septic shock.