Exposure to glufosinate ammonium, an herbicide used worldwide, can cause CNS and respiratory toxicities. This study aimed to analyze acute human glufosinate ammonium poisoning.

This multicenter retrospective cohort study involved five medical institutes affiliated with the Chang Gung Memorial Hospital system. Patients with glufosinate ammonium exposure visiting the emergency department (ED) between January 2008 and December 2020 were included.

In total, 95 patients were enrolled. Compared to exposure via the non-oral route, patients exposed orally (n = 61) had lower GCS scores, higher mortality rates, and longer hospital lengths of stay (P-value: <0.001, 0.002, and < 0.001, respectively). In the subgroup analysis among oral exposure patients, the survival group had a lower amount of estimated glufosinate ingestion than the non-survival group (10.5 [3.4–27] vs. 40.5 [27–47.3] g, P-value: 0.022), lower rate of substance co-exposure (9 [19.6%] vs. 10 [66.7%] P-value: 0.001), and lower rate of paraquat co-exposure (0 [0%] vs. 7 [46.7%] P < 0.001) compared with the mortality group. In the orally-exposed and non-paraquat co-exposure patients (n = 54), age > 70 years and GCS score < 9 at triage presented a high sensitivity (100.00%, 95% CI: 63.06–100.00%) and medium specificity (58.70%, 95% CI: 43.23–73.00%) in predicting mortality.

Old age, change in consciousness, and paraquat co-exposure were associated with higher mortality in human glufosinate poisoning. Age > 70 years and GCS score < 9 at triage could be predictors of mortality in patients with acute oral glufosinate poisoning.