Renal replacement therapy in the critical patient: treatment variation over time

Abstract

Objectives: To analyze the evolution of patients subjected to renal replacement therapy (RRT), and to determine risk factors associated with mortality and the recovery of renal function.

Design: A prospective, observational study of critically ill patients.

Setting: Clinical-surgical Intensive Care Unit (ICU) of Sabadell Hospital (Spain).

Patients: Inclusion of all patients treated in our Unit due to acute renal failure (ARF) requiring RRT.

Primary variables of interest: We recorded epidemiological data, severity using the APACHE II score, days of the technique, ICU mortality, and renal function recovery. The study period was divided into 2 parts: part 1 (2000-2004) and part 2 (2005-2009). The 2 periods were compared using the Student t-test for continuous variables and the chi-squared test for categorical variables. Multiple regression analysis was performed to determine the risk factors for mortality and recovery of renal function.

Results: A total of 304 patients were treated. Sepsis was the main etiology of ARF (61%), involving principally respiratory and abdominal foci. In the second period the convective technique and community-acquired ARF were far more prevalent than in the first period. There were fewer days of therapy in the second period (19.7 versus 12.3 days; P=.015). Total ICU mortality was 52.3%, with a decrease in the last period (61.9% to 45.5%: P=.003). The risk factors associated to mortality were creatinine upon admission (odds ratio [OR] 0.77; 95% confidence interval [95%CI] 0.61-0.97) and treatment with IHD alone (OR 0.37, 95%CI 0.16-0.87). Survivors had normal renal function at ICU discharge in 56.7% of the cases in the second period, vs in 72.9% in the first period, with more patients subjected to IHD in the second period (10.4% versus 26.8%). The factors related to the recovery of renal function were creatinine upon admission (OR 1.98, 95%CI 1.12-3.48), acute renal failure (OR 0.11, 95%CI 0.04-0.34) and treatment with continuous techniques (OR 0.18, 95%CI 0.03-0.85).

Conclusions: Mortality among critically ill patients subjected to RRT has improved in recent years.