Association between plasma paraquat level and outcome of paraquat poisoning in 375 paraquat poisoning patients

Objectives. Paraquat poisoning by ingestion is often fatal. Many studies have investigated treatment modalities and predictor parameters, but there is no standard treatment. Plasma paraquat concentration seems a valid predictable parameter of survival. In order to achieve uniform treatment, including extracorporeal elimination and antioxidant therapy, the outcome of paraquat poisoning based on plasma paraquat level needs to be investigated. Methods. This study included 375 paraquat poisoning patients who were diagnosed by means of plasma paraquat concentration within 24 hours after ingestion in the Institute of Pesticide Poisoning of Soonchunhyang University Cheonan Hospital, Korea, from January 2005 to December 2006. All patients were treated according to a uniform protocol including extracorporeal elimination and antioxidant therapy. Plasma paraquat concentration was measured by high-performance liquid chromatography. Results. The mean age of the paraquat-intoxicated patients was 48.42 +/- 6.75. One hundred ten patients (29.3%) survived. The upper limit of plasma paraquat concentration in survivors was 2.64 at 3 hour. All patients with plasma paraquat level above 3.44 died. The minimum paraquat level of the deaths was very low (0.12 mu g/ml at 5 hours; 0.02 mu g/ml at 12 hours; 0.01 mu g/ml at 24 hours). Conclusions. Our data showed that plasma paraquat concentration is good predictor of survivors but is not good predictor of non-survivors in the low plasma paraquat level.