Prognostic Factors in Patients with Paraquat Poisoning and Effect of Hemoperfusion

ABSTRACT

PURPOSE: Paraquat is a nonselective contact herbicide that may induce damage to many organs poisoned with it. Due to the high mortality associated with paraquat poisoning, a prediction of the outcome is a prerequisite for determining the therapeutic modality. METHODS: To identify prognostic factors for paraquat poisoning, the authors analyzed retrospectively the clinical features and outcomes of 45 patients (mean age 45.9 years; male-to-female ratio 1.1 1) poisoned with paraquat herbicides; they had been admitted to the emergency room of Kyungpook National University Hospital between June 1992 and June 2001. RESULTS: Most patients (91.1%) ingested liquid paraquat concentrate; twenty-six (62%) patients had intended to commit suicide. The overall mortality rate was 64.4% (29 patients); the mortality rate with ingestion of more than two mouthfuls was 93.3%. Seventy-six percent of the fatal cases expired within 2 days after intoxication. Azotemia, hypokalemia, hypoalbuminemia, leukocytosis, and decreased level of arterial PaCO2 and bicarbonate on the first hospital day were significantly related with mortality. Increased level of serum AST on the 4th hospital day was an additional marker of mortality. The survival rates according to the Yamaguchi index were significantly different (A 60%, B 12.5%, C 17%). There was no significant difference in the mortality rate between patients treated with and without hemoperfusion. CONCLUSION: Acid-base and electrolyte imbalances, an abnormal renal function, a low Yamaguchi index, and a positive urine paraquat test might be useful as early markers of poor prognosis. The effect of hemoperfusion remains to be determined by a further larger prospective study.