Clinical Presentation, Laboratory Abnormalities, and Predictors of Outcome in 103 Patients With Acute Paraquat Poisoning: A Prospective Observational Study

Abstract

Objectives: To study the clinical presentation and predictors of mortality in paraquat poisoning.

Design: Prospective observational study.

Setting: Tertiary care teaching hospital.

Subjects: Patients presenting with paraquat poisoning.

Interventions: We studied the clinical presentation, laboratory abnormalities, and predictors of mortality in 103 consecutive patients admitted to the medicine wards and medical ICU with acute paraquat self-poisoning from August 2023 to March 2024.

Measurements and Main Results: The mean age of the patients was 29.5 ± 10.5 years, there were 73 males (70.8%). The most common presenting symptom was vomiting (93%) followed by throat pain (85%). Of the 103, 78 patients died (75.7%). On univariate analysis, significantly higher median (interquartile range) amount of poison consumed (45 mL [20-100 mL] vs. 10 mL [5-10 mL]; p < 0.001), serum creatinine (6 mg/dL [3.8-8.9 mg/dL] vs. 1.9 mg/dL [0.8-3.2 mg/dL]; p < 0.001), serum bilirubin (5.9 mg/dL [3.7-9.5 mg/dL] vs. 1.1 mg/dL [0.7-3.3 mg/dL]; p < 0.001), and Acute Physiology and Chronic Health Evaluation II score (15.5 [12-19] vs. 7 [3.5-11]; p < 0.001) and a significantly lower ratio of Pao2/Fio2 at the time of admission (300 [150-400] vs. 420 [396-485]; p < 0.001) were evident in patients who died compared with survivors. An increasing trend in the mortality was observed with increasing International Program on Chemical Safety Poisoning Severity Score grade (p = 0.001). On multivariable analysis, shortness of breath (odds ratio [OR], 0.008; p = 0.072), hepatic dysfunction (OR, 0.012; p = 0.048), duration of hospital stay (OR, 1.030; p = 0.023), and presence of infiltrates on chest radiograph/CT chest (OR, 0.003; p = 0.011) emerged as significant independent predictors of mortality.

Conclusions: Paraquat is a lethal poison associated with a high mortality. Identification of predictors of mortality can facilitate early aggressive attempts at initiating appropriate treatment.