Two-Hour Lactate Clearance Predicts Negative Outcome in Patients with Cardiorespiratory Insufficiency

Abstract

Objective. To evaluate 2-hour lactate clearance as a prognostic marker in acute cardiorespiratory insufficiency. Design. Prospective observational study. Setting. Emergency Department (ED) and 16-bed medical High Dependency Unit (HDU). Methods and Main Results. 95 consecutive admissions from the ED for acute cardiorespiratory insufficiency were prospectively enrolled. Arterial lactate concentration was assessed at ED arrival and 1, 2, 6, and 24 hours later. The predictive value of 2-hour lactate clearance was evaluated for negative outcomes defined as hospital mortality or need for endotracheal intubation versus positive outcomes defined as discharge or transfer to a general medical ward. Logistic regression and ROC curves found 2-hour lactate clearance >15% was a strong predictor of negative outcome (P15% is highly predictive of positive outcome and may reassure clinicians that the therapeutic approach is appropriate.