Acute Renal Failure in the Medical ICU Still Predictive of High Mortality (Original Articles) (Intensive Care Units) (Clinical Report)
Acute renal failure (ARF) in the intensive care unit (ICU) is associated with mortality rates of 50 – 90%, (1) frequently occurring as part of multiple organ dysfunction syndrome in critically ill patients. (2) The high mortality is mostly due to severity of the underlying disease or co-existing condition, rather than the renal failure itself. (3-6) Risk factors for mortality include infection, oliguria, advanced age, sepsis, need for mechanical ventilation, number of failing organs and presence of circulatory shock. (4,7) Greater severity of illness and increasing co-morbidities in an ageing population may explain why technological advances in renal replacement therapy have had a disappointing effect on survival since they were first introduced in the 1960s. (6) The optimal treatment of ARF in the ICU remains undetermined. Investigations suggest that increased haemodialysis or haemofiltration results in a survival benefit. (5) The choice of dialysis in critically ill patients is controversial. Meta-analyses comparing continuous renal replacement therapy (CRRT) with conventional intermittent haemodialysis in unselected ICU patients found no significant difference in mortality. (1) However, compared with intermittent haemodialysis, CRRT had a lower mortality rate when patients of similar baseline severity of illness were compared. (1) Although a recent study (8) suggests that almost all patients with ARF as part of multiple-organ dysfunction syndrome requiring dialysis can be treated with intermittent haemodialysis as opposed to continuous veno-venous haemodialysis (CVVHD), both techniques produced similar outcomes.