Evaluation of Risk Factors for Mortality in Intensive Care Units: a Prospective Study from a Referral Hospital in Turkey

Background: The aim of the clinical practice is to decrease the mortality rate in intensive care units. Determination of the risk factors for mortality may provide useful guidance for intensive care patients. This study sought to find mortality-related risk factors in intensive care units.

Objective: To investigate risk factors for mortality in intensive care units (ICUs).

Methods: The prospective study was performed from May 2002 to November 2002 in the surgical and medical ICUs of the Ankara Numune Education and Research Hospital. Three hundred thirty-four patients who were followed in the ICUs for at least 48 hours were enrolled in this study. Those patients who died within 48 hours of ICU discharge were included in the mortality analysis.

Results: The overall mortality rate in the ICUs was 46.7%. Among the 334 patients, 104 (31.1%) had ICU-acquired infections. The mortality rate was significantly higher in the patients with nosocomial infections (66.3%) than in the patients without nosocomial infections (37.8%) ( P < .001). The mean age, sex, acute physiology and chronic health evaluation (APACHE) II score, trauma and intraabdominal pathology, nosocomial infection, stay in the medical/surgical ICU, coma, TISS score, use of steroid or chemotherapy, use of antibiotic, and serum urea >50 mg/dL and creatinine >1.2 mg/dL levels were associated with mortality in the univariate analysis. Eight variables were determined as independent risk factors: presence of nosocomial infection (hazard ratio (HR) 0.40; 95% confidence interval (CI), 0.27-0.61), mean age (HR, 1.01; 95% CI, 1.00-1.02), mean APACHE II score (HR, 1.99; 95% CI, 1.50-2.64), mechanical ventilation (HR, 1.98; 95% CI, 1.33-2.95), stay in the medical/surgical ICU (HR, 0.41; 95% CI, 0.27-0.61), enteral nutrition (HR, 0.43; 95% CI, 0.29-0.65), tracheostomy (HR, 0.26; 95% CI, 0.094-0.75), and use of steroid or chemotherapy (HR, 1.61; 95% CI, 1.13-2.29). Nosocomial pneumonia (HR, 0.59; 95% CI, 0.38-0.92) and sepsis (HR, 0.29; 95% CI, 0.16-0.51) were related with mortality.

Conclusion: The most important risk factors of mortality were observed as nosocomial infection, older age, high APACHE II score, mechanical ventilation, enteral nutrition, tracheostomy, and use of steroids or chemotherapy.