Incidence and risk factors of atrial fibrillation in a surgical intensive care unit*

Abstract

OBJECTIVE: To evaluate the incidence and risks factors of atrial fibrillation (AF). DESIGN: Prospective, observational study. SETTING: A surgical intensive care unit of a university hospital. PATIENTS: All patients with new onset of AF admitted in the surgical intensive care unit during a 6-month period. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: Of the 460 patients included in the study, AF developed in 24 patients (5.3%). According to univariate analysis, age, preexisting cardiovascular disease, and previous treatment by calcium-channel blockers were significant predictors of AF. Patients with AF received significantly more fluids and catecholamines and experienced more sepsis, shock, and acute renal failure. Severity (Simplified Acute Physiologic Score II), intensive care unit workload (OMEGA), intensive care unit and hospital length of stay, and mortality were significantly increased in patients who developed AF. Multivariate analysis identified five independent predictors of AF: advanced age, blunt thoracic trauma, shock, pulmonary artery catheter, and previous treatment by calcium-channel blockers. CONCLUSIONS: In surgical intensive care unit patients, the incidence of AF is greater than in the general population but less than in the cardiac surgery unit. The onset of AF reflects the severity of the disease. Five independent risk factors of AF were identified in surgical intensive care unit patients. The withdrawal of a calcium-channel inhibitor was also an independent risk factor of AF, and the weaning of this treatment must be carefully evaluated. Blunt thoracic trauma increases the chances of developing AF, as does the presence of shock, especially septic shock.