Prognostic factors in acute renal failure due to sepsis. Results of a prospective multicentre study

BACKGROUND.: Sepsis is a major cause of acute renal failure in hospital patients,but its incidence and the associated prognostic factors haverarely been assessed prospectively by multivariate analysis. METHODS.: We conducted a prospective 6-month study in 20 multidisciplinaryintensive care units to assess the prognosis of patients hospitalizedwith acute renal failure due to sepsis. Sepsis syndrome andseptic shock were defined according to the criteria of the Societyof Critical Care Medicine Consensus Conference. Severity scoringindexes (SAPS, APACHE II, and organ system failure (OSF)) weremeasured on ICU admission and on inclusion. The end-point washospital mortality. RESULTS.: Acute renal failure had a septic origin in 157 patients (Group1), comprising 68 with septic shock and 89 with sepsis syndrome,and did not result from infection in 188 patients (Group 2).Patients with septic acute renal failure were older (mean age:62.2 versus 57.9 years, P<0.02) and had on inclusion a higherSAPS (19.3 versus 16.1, P<0.001), APACHE II (29.6 versus24.3, P<0.001), and OSF (2.07 versus 1.52, P<0.001) thanpatients with non-septic acute renal failure. They had a higherneed for mechanical ventilation (69.1% versus 47.3%, P<0.001),and acute renal failure was more often delayed during the ICUstay than was present on admission (47.7% versus 32.4% respectively,P<0.005). Hospital mortality was higher in patients withseptic acute renal failure (74.5%) than in those whose renalfailure did not result from sepsis (45.2%, P<0.001). Mortalitywas influenced by the presence of a septic shock (79.4%) orof a sepsis syndrome on inclusion (70.8%). Using a stepwiselogistic regression model, sepsis was an independent predictorof hospital mortality (OR, 2.51; 95% CI, 1.44–4.39) aswell as a delayed occurrence of acute renal failure, oliguria,an altered previous health status, hospitalization prior toICU, need for mechanical ventilation, age and severity scoringindexes on inclusion. In total patients, mortality was higherin dialyzed than in non-dialyzed patients (P<0.001), andin those treated by continuous compared to intermittent techniques(P<0.01). Patients dialysed with biocompatible membraneshad a lower mortality than those treated with cellulose membranes(P<0.005). CONCLUSIONS.: Patients with acute renal failure due to sepsis have a worseprognosis than those with non-septic acute renal failure. Sepsisand the above-defined predictive factors are to be consideredin studies on prognosis of ARF patients. Our results suggestthat the use of biocompatible membranes may reduce significantlymortality in these patients.