Clinical studies on paraquat poisoning; prognosis and severity index of paraquat poisoning using the urine levels

Abstract

The prognosis of paraquat poisoning has been assessed from serum paraquat levels using e.g. produfoot survival curve. The prognosis of paraquat poisoning has not been investigated from urinary paraquat levels. The purpose of this study is to clarify whether the prognosis of paraquat poisoning can be determined by urinary paraquat levels or not. Urinary severity index of paraquat poisoning (U-SIPP) was employed. U-SIPP is calculated as hours between ingestion of paraquat and start of intensive treatment multiplied by the paraquat level in the urine at the same time. Urinary excretion of paraquat is correlated with renal function. The prognosis of paraquat poisoning using U-SIPP was further discussed, based on creatinine clearance (Ccr) and the relation between serum and urine paraquat levels. The following results were obtained. 1) When creatinine clearance was greater than 20 ml/min, patients who died of circulatory failure were with U-SIPP level over 1250, patients who died of respiratory failure were with U-SIPP level between 1250 and 250, and survivors were with U-SIPP below 250. 2) Survival duration was closely correlative with U-SIPP in cases with Ccr greater than 20 ml/min (r = 0.8123, p less than 0.025). 3) When Ccr was greater than 20 ml/min, urinary paraquat levels were correlated very well with the serum levels at admission, even during direct hemoperfusion (DHP) treatment. 4) When diuretic agents such as furosemide was effective, the assessment of the prognosis of paraquat poisoning using urinary paraquat levels seemed to be possible. Urinary paraquat level was approximately measured by an applied qualitative analysis method with using a dilution method.