Performance of the simplified acute physiology score III in acute organophosphate poisoning: A retrospective observational study

The performances of acute physiology and chronic health evaluation (APACHE) II and simplified acute physiology score (SAPS) II have previously been evaluated in acute organophosphate poisoning. We aimed to compare the performance of the SAPS III with those of the APACHE II and SAPS II, as well as to identify the best tool for predicting case fatality using the standardized mortality ratios (SMRs) in acute organophosphate poisoning. A retrospective analysis of organophosphate poisoning was conducted. The APACHE II, SAPS II, and SAPS III were calculated within 24 h of admission. Discrimination was evaluated by calculating the area under the receiver operating characteristic curve (AUROC). The SMRs were calculated as 95% confidence intervals (CIs). In total, 100 cases of organophosphate poisoning were included. The in-hospital case fatality was 19%. The median scores of the APACHE II, SAPS II, and SAPS III were 20.0 (10.0-27.0), 41.0 (28.0-54.8), and 53.0 (36.3-68.8), respectively. The AUROCs were not significantly different among the APACHE II (0.815; 95% CI, 0.712-0.919), SAPS II (0.820; 95% CI, 0.719-0.912), and SAPS III (0.850; 95% CI, 0.763-0.936). Based on these scores and in-hospital case fatality, the SMRs for the APACHE II, SAPS II, and SAPS III were 1.01 (95% CI, 0.50-2.72), 1.01 (95% CI, 0.54 -2.78), and 0.98 (95% CI, 0.33-1.99), respectively. The SAPS III provided a good discrimination and satisfactory calibration in acute organophosphate poisoning. It was therefore a useful tool in predicting case fatality in acute organophosphate poisoning, similar to the APACHE II and SAPS II.