Carbohydrate-deficient transferrin (CDT) is reported to have a higher specificity in alcoholism than conventional markers. As the morbidity and mortality rates amongst chronic alcoholics are raised following trauma, the objective was to investigate if CDT could be used to predict prolonged intensive care unit (ICU) stay and an increased morbidity in patients with multiple injuries admitted to the ICU. In this prospective double-blind study, 66 traumatized male patients were transferred to the ICU following admission via the emergency room and operative management. Blood samples for CDT determination were taken upon admission to the emergency room, the ICU and on days 2 and 4 following admission. The patients were allocated a priori to two groups: high CDT group (CDT >20 U/l on admission to the emergency room) and low CDT group (CDT < or = 20 U/l). CDT values were determined by microanion-exchange chromatography and radioimmunoassay. Thirty-six patients had an elevated CDT value on admission to the emergency room. The high CDT group had a significantly prolonged ICU stay (median high CDT group: 13 davs; median low CDT group: 5 days). Major intercurrent complications, such as alcohol-withdrawal syndrome, tracheobronchitis, pneumonia, pancreatitis, sepsis, and congestive heart failure, were significantly increased in the high CDT group. The increased risk of pneumonia in the high CDT group may be related to the significantly increased period of mechanical ventilation. As high CDT values were associated with an increased risk of intercurrent complications and a prolonged ICU stay, it seems reasonable to use CDT as a marker in intensifying research work into preventing alcoholism-associated complications.