Clinical and Biochemical Predictors of Mortality in Acute Organophosphorus Poisoning: A Prospective Observational Study from a Tertiary Care Centre in Central India

Background: Acute organophosphorus (OP) poisoning is a leading toxicological emergency in agrarian regions and carries substantial mortality. Cholinesterase assays are unavailable in many hospitals, so alternative early prognostic markers are needed. Aims/Objectives: To determine the association of admission clinical and biochemical markers with in-hospital mortality in acute OP poisoning, and to identify cut-offs for early risk stratification. Methodology: A prospective observational study enrolled 100 consecutive adults with acute OP exposure presenting within 24 hours to a tertiary care teaching hospital over 12 months. Glasgow Coma Scale (GCS), Peradeniya Organophosphorus Poisoning (POP) score, APACHE-IV score, serum creatine phosphokinase (CPK) and organ-function tests were recorded; patients were followed to discharge or death. Analysis used SPSS v25 with receiver operating characteristic (ROC) curves. Results: Mortality was 16%. Non-survivors had lower mean GCS (9.3±1.5 vs 13.5±2.1), higher POP (5.2±0.8 vs 2.7±1.6) and APACHE-IV (67.6±19.2 vs 27.5±15.3) scores, and higher day-3 CPK (1530.87±420.88 vs 154.44±94.10 IU/L); all p<0.05. Fasciculations, bradycardia, CNS depression and ventilatory support also predicted death. Areas under the curve were 0.964 (atropine dose), 0.937 (APACHE-IV), 0.922 (GCS), 0.915 (CPK) and 0.904 (POP score); a POP score ≥4 was 100% sensitive. Conclusions: Bedside severity scores and serial CPK are inexpensive, reliable predictors of mortality and permit early risk stratification where cholinesterase assays are unavailable.