OBJECTIVETo investigate the relationship between semi-quantification of urine paraquat and the severity of acute paraquat poisoning, and to evaluate the prognostic value of the test in patients with acute paraquat poisoning.

METHODSA total of 179 patients with acute paraquat poisoning were categorized into four groups according to their semi-quantification results of urine paraquat: +group (n = 36), ++group (n = 23), +++ group (n = 25), and ++++group (n = 95). The clinical features, severity of hepatic and renal injuries, respiratory failure, and clinical classification were compared between these four groups. Kaplan-Meier analysis was used to evaluate the survival rate.

RESULTSThe 60-day mortality was 45.25% (81/179). The amount of ingestion increased significantly from +group to ++++group (P < 0.05). No patient in +group was found to have serious complications, while most patients in ++++group suffered organ dysfunction or even organ failure. The incidence of acute respiratory failure, renal failure, and hepatic failure in ++++group was significantly higher than that in +group, ++group, and +++group (P < 0.05). The urine paraquat concentration was positively correlated with the clinical severity of acute paraquat poisoning (Spearman correlation coefficient = 0.720, P < 0.01). Kaplan-Meier survival analysis showed that the mortality of ++++group (73.7%) was significantly higher than that of +++group (40%), ++group (4.3%), and +group (0%) (P < 0.05).

CONCLUSIONThe semi-quantification of urine paraquat is a promising test in evaluating the severity of acute paraquat poisoning. This test can be used to guide therapy and to predict the outcomes of patients suffering acute paraquat poisoning.