Anion gap, anion gap corrected for albumin, and base deficit fail to accurately diagnose clinically significant hyperlactatemia in critically ill patients.

Anion gap, anion gap corrected for serum albumin, and base deficit are often used as surrogates for measuring serum lactate. None of these surrogates is postulated to predict hyperlactatemia in the critically ill. We prospectively collected data from September 2004 through August 2005 for 1381 consecutive admissions. Patients with renal disease, ketoacidosis, or toxic ingestion were excluded. Anion gap, anion gap corrected for albumin, and base deficit were calculated for all patients. We identified 286 patients who met our inclusion or exclusion criteria. The receiver-operating characteristic area under the curve for the prediction of hyperlactatemia for anion gap, anion gap corrected for albumin, and base deficit were 0.55, 0.57, and 0.64, respectively. Anion gap, anion gap corrected for albumin, and base deficit do not predict the presence or absence of clinically significant hyperlactatemia. Serum lactate should be measured in all critically ill adults in whom hypoperfusion is suspected.