Comparison of serum amylase and creatine phosphokinase levels in assessing the severity of organophosphate poisoning

Abstract

Introduction: Organophosphate compounds are widely used pesticides that cause significant morbidity and mortality worldwide, particularly in developing countries. The inhibition of acetylcholinesterase enzyme leads to accumulation of acetylcholine, resulting in characteristic cholinergic manifestations. While acetylcholinesterase levels are the gold standard for diagnosis and severity assessment, their limited availability in resource-constrained settings necessitates exploration of alternative biomarkers. This study aimed to evaluate serum amylase and creatine phosphokinase (CPK) as potential markers for assessing the severity of organophosphate poisoning and to correlate these findings with clinical severity and outcomes. Materials and Methods: This prospective study included 73 patients with organophosphate poisoning admitted to a tertiary care center. Clinical severity was assessed using the Peradeniya Organophosphorus Poisoning (POP) scale. Serum acetylcholinesterase, amylase, and CPK levels were measured on days 1, 3, and 5 of hospitalization. Statistical analysis was performed to determine correlations between biochemical parameters and clinical severity, as well as their associations with outcomes. Results: Among the 73 patients, 67.1% were young adults (21-40 years), with a nearly equal gender distribution. Based on the POP scale, 43.8% had mild poisoning, 39.7% moderate, and 16.4% severe. Elevated serum amylase levels (>110 units) were observed in 63% of patients on day 1, while elevated CPK levels (>200 units) were noted in 16.4%. Strong correlations were found between the POP score and both amylase (r=0.865, p<0.001) and CPK levels (r=0.817, p<0.001). Acetylcholinesterase levels on admission were significantly associated with mortality, with lower levels (<5320 units) corresponding to higher mortality rates (34.5% vs. 6.7%, p=0.034). Ventilatory support was required in 26% of patients, and the overall mortality rate was 15.1%. Conclusion: Serum amylase and CPK levels demonstrate strong correlations with clinical severity in organophosphate poisoning, with amylase exhibiting a slightly stronger correlation. These readily available biochemical markers can serve as valuable adjuncts to clinical assessment in determining severity and predicting outcomes, particularly in settings where acetylcholinesterase assays are not available. Future research with larger sample sizes is warranted to establish definitive cut-off values for these markers in clinical decision-making.