Is Simplified Acute Physiology Score 3 better than APACHE II to predict mortality in transplanted critical patients?

Introduction

The performance of general prognostic models in patients with transplantation in need for ICU admission is poor, showing a tendency towards significant underestimation of the risk of dying. The objective of our study is to evaluate the APACHE II score and Simplified Acute Physiology Score (SAPS) 3 and their 90-day mortality prediction after liver, renal and pulmonary transplantation.

Methods

A prospective cohort study in a transplantation ICU in Porto Alegre, Brazil, during the period May 2006 to July 2007. Clinical data of 277 post-transplantation patients admitted to the ICU were collected at admission and the SAPS 3 and APACHE II score calculated with respective estimated mortality rates. The area under the receiver operating characteristic curve (AUROC) was obtained for both scores.

Results

Patients enrolled included 172 men and 105 women, with mean age 45 ± 2 years. There were 86 (31%) liver transplantations, 170 (61.3%) renal transplantations and 21 (7.6%) pulmonary transplantations. The 90-day mortality for liver, renal and pulmonary transplantation was: 12 (15.4%), four (3%) and four (26.3%). The mean SAPS 3 score was 40 ± 10.2, 21 ± 5.8 and 63 ± 19, and the APACHE II score was 25 ± 8.2, 16 ± 5.9 and 17 ± 21.4, respectively. Comparing the AUROC from both scores we observed: in liver transplantation the AUROC for SAPS 3 was 0.677 (95% CI = 0.447 to 0.887) versus 0.749 (95% CI = 0.623 to 0.875) for APACHE II; in renal transplantation the AUROC for SAPS 3 was -0.619 (95% CI = 0.355 to 0.882) versus 0.604 (95% CI = 0.355 to 0.882) for APACHE II; in pulmonary transplantation the AUROC for SAPS 3 was -0.936 (95% CI = 0.805 to 1.06) versus 0.750 (95% CI = 0.489 to 1.01) for APACHE II.

Conclusion

In these preliminary results, no differences were observed comparing SAPS 3 and APACHE II in the mortality prediction from liver, renal and pulmonary transplanted patients.