Outcome and predictive factors of acute renal failure in the intensive care unit

Abstract

The development of acute renal failure (ARF) in the ICU setting carries a high morbidity and mortality. To assess the outcomes and its predictive factors in our ICU, we analyzed the data of patients with ARF treated during 18 months. The 33 patients included 21 men and 12 women of mean age 51 ± 21.7 years (13 to 87). Sepsis with multi-organ dysfunction (MOD) was the leading cause of ARF (58%). Comorbid conditions were malignancy in 30% of patients, diabetes mellitus in 24%, hypertension in 21%, ischemic heart disease in 21%, liver disease in 15%, and chronic renal failure in 15%. Predisposing factors were hypotension in 67% of cases, dehydration in 36%, drug related in 33%, congestive heart failure in 24%, and liver cirrhosis in 6%. Twenty-five (76%) patients needed mechanical ventilation, 22 (67%) were anuric, 18 (55%) had MODS, and 15 (45%) needed inotropic support. Length of stay in hospital was 27.2 ± 28.0 days (2 to 94). Nineteen patients (58%) were managed conservatively and 14 (42%) by renal replacement therapy. Patient mortality was 67% and renal mortality 52%. The impact of the following factor: was assessed on patient and renal outcome was assessed ventilation support, presence of oliguria, need for inotropes, and presence of MOD. Patient mortality was significantly influenced by an elevated odds ratios (OR) (95% CI): mechanical ventilation [OR = 34 (95% CI 1.95 to 538)], and presence of MODS [OR = 12.3 (95% CI 2 to 75)]. Renal mortality was influenced by mechanical ventilation [OR = 12.3 (95% CI 1.6 to 119)], oliguria [OR = 12 (95% CI 2 to 72)], inotrope support [OR = 10 (95% CI 2 to 52), and MOD [OR = 35 (95% CI 3.5 to 35.0)]. This study confirms the high patient and renal mortality of ARF among patients to ICU. The four parameters were excellent predictors of renal outcome, while only the need for mechanical ventilation and the presence of MOD were predictors for patient survival.