ObjectiveTo explore the clinical characteristics and risk factors of acute kidney injury (AKI) in patients with diquat mixed with paraquat poisoning.

MethodsWe retrospectively analyzed the clinical data of 210 patients admitted to the department of emergency at our hospital with paraquat, diquat or mixed poisoning from January 20, 2016, to June 10, 2024. Based on the detection results of plasma toxicants, patients were categorized into three groups: the paraquat group (PQ group), and the diquat group (DQ group), the diquat-paraquat mixed group (mixed group). We compared clinical indices, occurrence, and severity of AKI among these groups. In the mixed group, patients were further divided into AKI and non-AKI subgroups based on the presence of AKI during hospitalization, and differences in clinical indices between these subgroups were analyzed. Univariate logistic regression and least absolute shrinkage and selection operator (Lasso) regressions were used to screen risk factors, and multivariate logistic regression was applied to establish the model. ROC curves were generated, and factors influencing AKI occurrence in the mixed group were identified.

ResultsA total of 88 patients were included in the PQ group, 28 in the DQ group, and 57 in the mixed group. Significant differences were observed among the three groups in terms of age, mortality rate, ingestion amount, body mass index(BMI), occurrence of AKI, the incidence of organ support therapy, SIRS score, PSS score, and APACHE Ⅱ score on admission ( P < 0.05). All three groups exhibited various degrees of AKI, with the mixed group showing a higher proportion and more severe conditions. In the mixed group, compared with the non-AKI group, the AKI group showed significantly higher values for age, number of deaths, ingestion amount, SIRS score, PSS score, APACHE Ⅱ score, plasma PQ concentration on admission, plasma DQ concentration on admission, white blood cell count (WBC), neutrophil count (NEUT), monocyte count (MONO), serum creatinine (SCr), procalcitonin (PCT), c-reactive protein (CRP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood lactic acid (Lac), and cystatin C (CysC) ( P < 0.05). Conversely, the estimated glomerular filtration rate (eGFR) and partial pressure of carbon dioxide (PCO2) were significantly lower in the AKI group ( P < 0.05). Additionally, in the mixed group, SCr levels at various times post-poisoning were significantly higher compared with the non-AKI group ( P < 0.05), showing an increasing trend and peaking at 212.19 ± 101.67 μmol/L on the fifth day after poisoning. Age, ingestion amount, SIRS score on admission, WBC, MONO, and PCO ₂ were extracted by Lasso-Logistic regression. Multivariate logistic regression identified ingestion amount and SIRS score on admission as the independent risk factors for the occurrence of AKI in the mixed group. The area under the ROC curve for ingestion amount and SIRS score on admission was 0.991 (95% CI: 0.976-1.000), the sensitivity was 0.940 and the specificity was 1.000.

ConclusionsThe diquat mixed with paraquat poisoning is associated with a higher incidence and greater severity of AKI compared with poisoning with either PQ or DQ alone. Additionally, ingestion amount and SIRS score on admission have been identified as independent risk factors for the occurrence of AKI in patients with the mixed poisoning. The combined assessment of these two factors improves AKI prediction in patients with the mixed poisoning.