ICU SCORING SYSTEMS (APACHE II, APACHE IV, SAPS III) IN AN INDIAN ICU - OBSERVED MORTALITY AND ITS CORRELATION WITH PREDICTED MORTALITY

Abstract

Vimal Kumar Palaniappan1, Nirmal Kumar Palaniappan2, Vivekanandan M3, Sagiev Koshy George4

BACKGROUND
Intensive care has developed over the past four decades in treating critically-ill patients. The cost of providing the intensive care services are also squaring up to astronomical levels. Risk scoring systems can be used to focus on quality of care provided to patients at ICU setup as they help in comparative audit that is comparison of actual and expected outcome for group of patients that can be used to compare different providers.
The aim of the study is to-
1. Study the usefulness of ICU scoring systems (APACHE II, APACHE IV and SAPS III) developed in the west in an Indian ICU.
2. Calculate scores of patients admitted in our ICU as per various ICU scoring systems (APACHE II, APACHE IV and SAPS III).
3. To document the observed mortality among these patients.
4. To compare the observed mortality with mortality predicted by scoring systems (APACHE II, APACHE IV and SAPS III) to see if these ICU scoring systems developed in the West can predict mortality in an Indian ICU.
MATERIALS AND METHODS
The study was a prospective study over a period of one year (2011-2012) and patients are enrolled as per inclusion criteria. Sample size was set to be a minimum of 100. The physiological parameters, lab investigations, surgical status, chronic health condition including the demographic details as needed by scoring systems (APACHE II, APACHE IV, SAPS III) were recorded at the time of admission to ICU. Patients were followed up till the time of discharge and mortality among the study patients were documented.
Statistical Analysis- Statistical analysis is done by using SPSS software.
RESULTS
This prospective study of 115 ICU patients evaluated the three ICU scoring systems namely, APACHE II, APACHE IV and SAPS III in ICU of a tertiary care corporate hospital shows there is a linear correlation between the scores and observed mortality with increasing scores, the observed mortality progressively increases. This suggests that the scoring systems are valid and can accurately predict mortality in Indian setting also the observed mortality in our cohort of patients is 40%. However, the predicted mortality as per APACHE II, APACHE IV, and SAPS III is only 33.51%, 33.5% and 28.53%. The risk of death for a given patient in our ICU with mean predicted mortality (SMR) is 1.2, 3.61 and 1.4 times that of the mortality predicted by scoring systems APACHE II, APACHE IV, and SAPS III, respectively. After obtaining the score for individual patients, the mortality predicted by the scoring systems should be multiplied by the above factor. Different ICU will have different SMR for any given scoring system depending on the standard of care of that particular ICU. So, individual intensive care units should establish their own SMR for any particular scoring system. SAPS III admission scoring in predicting mortality risk stands good as it is recorded within one hour of ICU admission and other scoring systems may be influenced by treatment. The limitations of the study are that the number of patients in the study is small to establish statistical significance. In addition, our study evaluated predominantly medical patients and may not be applicable to other types of ICU patients.
CONCLUSION
There is a linear correlation between the predicted scores and observed mortality with increasing scores, the observed mortality progressively increases. This suggests that the scoring systems are valid and can accurately predict mortality in Indian setting also.

image