Two Routine Blood Tests—Mean Corpuscular Volume and Aspartate Aminotransferase—as Predictors of Delirium Tremens in Trauma Patients

Abstract

Delirium tremens (DT) in trauma patients is associated with significant morbidity and mortality. Short interview tools have been used to determine the risk of DT but require an alert, compliant patient and a motivated physician. The mean corpuscular volume (MCV) and aspartate aminotransferase (AST) levels are parts of routine laboratory testing, influenced by excessive alcohol consumption, and may serve as predictors of DT. This study examines the predictive ability of these two readily available biological markers. The records of 423 consecutive trauma patients who presented to a Level I trauma center with a positive toxicology screen for alcohol were reviewed. The outcome variable was DT, as defined by the presence of tremor, diaphoresis, autonomic instability, and hallucinations. The positive predictive value (PPV), negative predictive value (NPV), and likelihood ratio (LR) of the admission MCV and AST values were calculated for the prediction of DT. Of the 336 patients who met the criteria for study participation, 110 were diagnosed with DT due to alcohol withdrawal. When the admission MCV and AST were normal, only 3 patients (3.8%) developed DT. The NPV, PPV, and LR with two normal values together were 58.2%, 3.8%, and 0.080, respectively. When both were abnormal, 72 patients (64.3%) developed DT. The NPV, PPV, and LR with two abnormal values together were 83%, 64.3%, and 3.698, respectively. Normal admission MCV and AST values in intoxicated trauma patients nearly exclude the development of DT.