Predictors of mortality in acute paraquat poisoning: south indian cohort analysis

Abstract

Background: Acute paraquat poisoning is associated with high mortality, particularly in agrarian regions of South Asia. Early identification of prognostic factors is critical for guiding emergency management in resource-limited settings. Methods: This prospective observational cohort study included 84 consecutive adults with laboratory-confirmed acute paraquat poisoning presenting to a tertiary care emergency department in South India. Demographic, exposure, clinical, and laboratory variables—including urine dithionite score and PaO₂/FiO₂ ratio—were recorded. The primary outcome was in-hospital mortality. Multivariable logistic regression was used to identify independent predictors. Results: Overall mortality was 66.7%. Non-survivors had higher ingestion volumes, longer delays to presentation, and worse admission parameters. After adjustment, ingestion >20 mL (OR 8.45; p<0.001), urine dithionite score ≥2 (OR 6.91; p=0.001), and time to emergency department ≥4 hours (OR 4.82; p=0.004) were the strongest predictors of mortality. Reduced eGFR <75 mL/min/1.73 m² (OR 3.78; p=0.012), PaO₂/FiO₂ ratio <290 (OR 3.45; p=0.024), and CRP >50 mg/L (OR 2.98; p=0.041) were also independently associated with death. Conclusion: Acute paraquat poisoning carries high mortality. Readily available clinical and laboratory parameters may enable early risk stratification and support timely decision-making in emergency settings, particularly in resource-limited environments.