Plasma Paraquat Concentration and the Severity Index of Paraquat Poisoning (SIPP) at Presentation in Paraquat Intoxication

ABSTRACT

PURPOSE: Paraquat is a chemical which causes death in 30~80% of patients even after ingestion of small quantities. In spite of much studies, there are no successful treatment modalities or predictive parameters for determining the prognosis of the poisoning. The aims of this study were to evaluate plasma-paraquat concentration and initial laboratory and clinical data as prognostic parameters in patients with paraquat poisoning. METHODS: A retrospective analysis by chart review was done on 168 patients over three years who had ingested paraquat. The patients were divided into two subgroups based on survival and evaluated for ingested amounts of paraquat, the time between ingestion and treatment, urine dithionite test, and plasma paraquat concentration at the time of emergency department (ED) visit. Other clinical and laboratory factors such as age, sex, serum biochemical parameters, and severity index of paraquat poisoning (SIPP) were also analyzed. RESULTS: The plasma paraquat concentrations in the mortality group were higher than in the survival group (51.59+/-55.07 vs. 1.09+/-3.09 microgram/mL, p<0.001). The SIPP was higher in the mortality group as well (173.87+/-219.67 vs. 5.18+/-13.51 microgram/mL/hour). Among the laboratory data obtained in the ED, s-Potassium, s-Protein, arterial pH, PaCO2, bicarbonate, s-Albumin, s-Amylase, AST, BUN, s-Creatinine, and s-Glucose were significant factors which could affect the prognosis for paraquat poisoning. A Cox regression analysis revealed that plasma paraquat concentration, SIPP, s-Creatinine, s-Protein, s-Potassium and bicarbonate were associated with mortality. In addition, SIPP was more significantly correlated with mortality than plasma paraquat concentration (OR 1.362 vs. 1.011, p<0.001 vs. 0.019). CONCLUSION: Initial laboratory parameters including s-creatinine, s-protein, s-potassium, bicarbonate, plasma Paraquat concentration, and SIPP were significant prognostic factors. In addition, the author suggests that SIPP is a better index than plasma paraquat concentration for predicting the outcome of patients admitted for ingestion of paraquat.