Factors affecting the outcome of acute renal failure among the elderly population in India: a hospital based study

The spectrum of acute renal failure (ARF) in the elderly population and the factors predicting poor outcome in these patients are not well defined in literature. Identification of risk factors and poor prognostic markers in these patients can help in planning strategies to prevent ARF and to prioritise the utilization of sparse and expensive therapeutic modalities, especially in a developing country like ours. We retrospectively analyzed data of 454 elderly patients (age >= 60 years), detected having ARF in a tertiary care super-speciality hospital in North India, from April 2000 to March 2004. The mean age of this population was 66.4 years with 70.5% being male. 64% patients had more than one precipitating factors for ARF, with volume depletion being the most common precipitating factor (33% cases). Infection/ sepsis (21.6%) and drugs (11.5%) were other important precipitating factors. 31.8% were recorded as having oliguric ARF (urine output < 400 ml/day) and 33.5% required renal replacement therapy (RRT). Acute peritoneal dialysis was the most frequent form of RRT given (62.5%). Mortality was 41.2% (187 cases), of whom 56 (29.8%) died inspite of recovery from ARE Among the survivors, 103 patients (22.7%) had complete renal recovery, 141 (31.1%) had partial renal recovery, while 23 (8.6%), remained dialysis dependent. The factors which were found to be associated with increased mortality were; age >= 70 years, presence of previous chronic illness, ARF precipitated by cardiac failure and infection, need for RRT, oliguria and increasing numbers of failed organs. To conclude, ARF among elderly is a common problem in nephrology practice at our institute and is responsible for 48.9% of nephrology admissions/ consultations among elderly patients. Majority of these patients are prone to multiple renal insults. Underlying chronic illness, presence of cardiac failure and sepsis, oliguria, need for RRT and increasing number of organ failure are associated with poor outcome.