Apache II Scoring as an Index of Severity in Organophosphorus Poisoning

Objectives: The purpose of the study was to determine the mortality rate in organophosphate poisoning patients and relationship between the clinical severity of OPP with APACHE II score and serum cholinesterase levels. Methodology: This is a cross sectional study conducted in medical intensive care unit. Baseline variables and clinical characteristics were summarized with frequencies (percentages) for categorical variables and mean (standard deviation) for continuous variables. Receiver operating characteristic (ROC) curves were generated with a 95% CI to assess the relationship between individual APACHE II scores and mortality rates. Results: The patient’s average age was 25.16 ± 9.95 years. 56.6% were female and 78.8% patients were suicidal. Patient who had stayed in the hospital >15 days had 33.3% mortality (p=0.13). Total 12 (10.6%) patients required mechanical ventilation out of which only one (8.3%) patient expired (p=0.86). The average APACHE II score was 3.73 ± 3.95. The APACHE II score for predicting death risk had fair discrimination as indicated by ROC curve of 0.67 (CI. 0.512-0.833). There was no significant association (p=0.29) between serum cholinesterase level and APACHE II score regarding the severity of poisoning. However, significant association (p<0.001) was found between outcome and serum cholinesterase levels. Conclusion: The mortality rate reported was 9.7%. There was no significant association between serum cholinesterase level and APACHE II score regarding the severity of poisoning. However, significant association was found between outcome and serum cholinesterase levels.