Acute renal failure in intensive care units--Causes, outcome, and prognostic factors of hospital mortality : A prospective, multicenter study

Investigations describing the utilization pattern and documenting the value of intensive care are limited by the lack of a reliable and valid classification system. In this paper, the authors describe the development and initial validation of acute physiology and chronic health evaluation (APACHE), a physiologically based classification system for measuring severity of illness in groups of critically ill patients. APACHE uses information available in the medical record. In studies on 582 admissions to a university hospital ICU and 223 admissions to a community hospital ICU, APACHE was reliable in classifying ICU admissions. In validation studies involving these 805 admissions, the acute physiology score of APACHE demonstrated consistent agreement with subsequent therapeutic effort and mortality. This was true for a broad range of patient groups using a variety of sensitivity analyses. After successful completion of multi-institutional validation studies, the APACHE classification system could be used to control for case mix, compare outcomes, evaluate new therapies, and study the utilization of ICUs.

We used 14 easily measured biologic and clinical variables to develop a simple scoring system reflecting the risk of death in ICU patients. The simplified acute physiology score (SAPS) was evaluated in 679 consecutive patients admitted to eight multidisciplinary referral ICUs in France. Surgery accounted for 40% of admissions. Data were collected during the first 24 h after ICU admission. SAPS correctly classified patients in groups of increasing probability of death, irrespective of diagnosis, and compared favorably with the acute physiology score (APS), a more complex scoring system which has also been applied to ICU patients. SAPS was a simpler and less time-consuming method for comparative studies and management evaluation between different ICUs.

This prospective study describes the current prognosis of patients in acute Organ System Failure (OSF). Objective definitions were developed for five OSFs, and then 5677 ICU admissions from 13 hospitals were monitored. The number and duration of OSF were linked to outcome at hospital discharge for each of the 2719 ICU patients (48%) who developed OSF. For all medical and most surgical admissions, a single OSF lasting more than 1 day resulted in a mortality rate approaching 40%. Among both medical and surgical patients, two OSFs for more than 1 day increased death rates to 60%. Advanced chronologic age increased both the probability of developing OSF and the probability of death once OSF occurred. Mortality for 99 patients with three or more OSFs persisting after 3 days was 98%. The two patients who survived were both young, in prior excellent health, and had severe but limited primary diseases. These results emphasize the high death rates associated with acute OSF and the rapidity with which mortality increases over time. The prognostic estimates provide reference data for physicians treating similar patients.