Factors associated with severe effects following acute glufosinate poisoning.

CONTEXT: In acute glufosinate poisoning, sudden respiratory arrest and convulsion can occur after a latent period of 4-60 h. There is still no factor that accurately predicts the occurrence of these symptoms.

OBJECTIVE

To elucidate the predictors of severe effects following acute glufosinate poisoning.

MATERIALS AND

METHODS

This study is a retrospective observational case series. The subjects were 16 patients who had acute glufosinate poisoning. They were divided into a group with respiratory arrest or convulsion during hospitalization (severe group) and a group without (non-severe group). The following characteristics (or predictors) were compared between the groups: age, sex, calculated amount of glufosinate (volume of ingested poison (glufosinate-containing herbicide) × glufosinate concentration of the product), time duration from poison ingestion to arrival at our hospital, use of gastric lavage, use of whole bowel irrigation, Glasgow Coma Scale, laboratory parameters, PaO₂/FiO₂ ratio (P/F ratio), shock index, and presence or absence of systemic inflammatory response syndrome (SIRS) on arrival.

RESULTS

The P/F ratio was significantly lower in the severe group than in the non-severe group (median, 287.5 vs. 409.0; P = 0.049). The receiver operating characteristic (ROC) curve was plotted for the predictor of increasing severity based on the P/F ratio. The area under the curve was 0.714, and the optimal cutoff point for increasing severity was 374.0. The sensitivity was 75.0%, specificity of 71.4%, and accuracy of 75.0%. The shock index was significantly higher (median, 0.52 vs. 0.41; P = 0.031). Significantly more patients had SIRS in the severe group than in the non-severe group (P = 0.015). Logistic regression analysis was performed with a backward elimination procedure. SIRS was selected as the independent predictor of increasing severity (odds ratio, 29.810; 95% confidence interval, 1.011-878.952; P = 0.049).

DISCUSSION AND

CONCLUSION

Severe effects following acute glufosinate poisoning were associated with two positive SIRS criteria. A low P/F ratio may be useful for predicting the occurrence of respiratory complications.