Electrolyte Imbalance as a Prognostic Marker in Acute Organophosphorus Poisoning: A Cross-Sectional Study

Background: Acute organophosphorus poisoning (OPP) causes morbidity and mortality. Hypokalemia may reflect poisoning severity and adverse outcome but is not routinely used for risk stratification. Material and Methods: This cross-sectional study included 150 adults with acute OPP at a tertiary teaching hospital in Western India between April 2024 and September 2025. Patients with pregnancy, chronic kidney disease, diabetes mellitus, or mixed-poison ingestion were excluded. Admission clinical, electrolyte, renal, arterial blood gas and cholinesterase parameters were recorded. Severity was graded using the Peradeniya Organophosphorus Poisoning (POP) scale. One-way ANOVA, Student’s t-test and chi-square test were used; P ≤ 0.05 was significant. Results: Of 150 patients, 70.7% were male and 52.0% were aged 18–25 years. Nausea (96.0%), vomiting (92.7%) and breathing difficulty (80.7%) were common. Mild, moderate and severe poisoning occurred in 70.0%, 22.7% and 7.3%, respectively. Mean potassium decreased from 3.95 ± 0.41 mmol/L in mild to 3.40 ± 0.50 in moderate and 2.95 ± 0.33 mmol/L in severe poisoning (P < 0.001). Hypokalemia increased from 17.1% to 67.6% and 81.8%, respectively (P < 0.001). Mortality increased from 0% to 14.7% and 36.4% across POP grades (P < 0.001) and was higher in hypokalemic than normokalemic patients (14.0% vs 2.0%; P = 0.039). Conclusion: Admission hypokalemia is associated with POP severity and mortality in acute OPP and may serve as a low-cost bedside prognostic marker.