Acalculous cholecystitis in severely burned patients: incidence and predisposing factors

OBJECTIVE: To investigate the incidence and predisposing factors of acalculous cholecystitis (AAC) in severely burned patients. BACKGROUND DATA: Although some studies report on AAC in critically ill patients, very little is known about AAC after severe burns. METHODS: We conducted a retrospective cohort study involving patients with burns admitted to the burn intensive care unit (BICU) of a university hospital. The patient cohort was divided into two groups (AAC group: burned patients with histological proven acalculous cholecystitis, n=15; Control group: population of all other burned patients admitted to the BICU, n=1225). Univariate and multivariate analyses were used to identify predisposing factors for the development of AAC. RESULTS: Fifteen patients with acalculous cholecystitis were identified in the study period. This represents 1.2% of all significant burns admitted. Comparing the AAC group with the Control population the following patients' characteristics, therapeutic measures and outcome parameters were significantly different in the univariate analysis: mean age (54.0 years vs. 42.0 years), BMI (28.9 kg/m(2) vs. 25.6 kg/m(2)), abbreviated burn severity index (8.3 vs. 6.4), total body surface area burn deep partial thickness (12.0% vs. 6.2%) and full thickness (10.2% vs. 6.8%), concomitant inhalation injury (80.0% vs. 28.9%), sepsis (46.7% vs. 14.9%), catecholamine (100% vs. 30.4%) and antibiotic requirement (100% vs. 58.2%), non-biliary tract operations (4.9 vs. 1.5), BICU length of stay (63.4 days vs. 21.0 days), ventilator days (50.3 vs. 11.9), packed red blood cells (PRBCs) administration (70.0 units vs.13.0 units) and mortality (53.3% vs. 19.7%). In the multivariate analysis however, only age, the number of administered units of PRBCs and the duration of mechanical ventilation turned out to be independent predictors for the occurrence of AAC. CONCLUSION: AAC is a rare complication of severely burned patients and may reflect the severity of the patient's general conditions. Predisposing factors for AAC are advanced age, the need of blood transfusions and prolonged mechanical ventilation. In the presence of these predisposing factors, early monitoring may help to detect AAC earlier and to initiate appropriate intervention.