Interpretation of blood lactate measurements in paediatric open-heart surgery and in extracorporeal membrane oxygenation

For the purpose of demonstrating both the clinical value and economic advantages of using blood lactate as a marker for haemodynamic instability, we present the clinical guidelines for when to measure blood lactate and how these measurements are interpreted in two clinical settings: following open-heart surgery for complex congenital heart disease, and in determining both the need for and the effectiveness of extracorporeal membrane oxygenation (ECMO). Several case histories are presented that demonstrate the conditions which can elevate blood lactate concentrations and the resulting therapeutic interventions, based on use of volume support, inotropic support, vasodilators, and/or ventilation, that can lead to a successful outcome in these patients. In one of the case histories a greatly elevated blood lactate apparently indicated that intracranial hemorrhage had occurred in a patient who later expired.