OBJECTIVETo investigate the prognostic values of initial serum paraquat (PQ) concentration and time lag after PQ ingestion in patients with PQ poisoning.

METHODSA retrospective analysis was performed on 189 patients who ingested PQ between 2.5 and 48 h before admission. The values of initial serum PQ concentration and time lag after PQ ingestion for the prognosis after poisoning were analyzed by the receiver operating characteristic (ROC) curve and multiple logistic regression analysis.

RESULTSThe serum PQ concentration of non-survivors was significantly higher than that of survivors (P<0.01) , and the time lag after PQ ingestion of non-survivors was significantly longer than that of survivors (P<0.01). The ROC curve analysis showed that the area under the ROC curve (AUC) showed no significant difference between initial serum PQ concentration and serum PQ concentration-time data when the time lag after PQ ingestion was between 2.5 and 48 h (z=0.563, P=0.574) ; the AUC showed a significant difference between initial serum PQ concentration and serum PQ concentration-time data when the time lag after PQ ingestion was between 2.5 and 6 h (z=2.199, P=0.034) and between 6 and 48 h (z=2.525, P=0.012).

CONCLUSIONInitial serum PQ concentration has a better predictive power than serum PQ concentration-time data in evaluating the prognosis of patients when the time lag after PQ ingestion is within 6 h. However, serum PQ concentration-time data has a better predictive power than PQ concentration alone in evaluating the prognosis of patients when the time lag after PQ ingestion is between 6 and 48 h.