Predictors of acute kidney injury after paraquat intoxication

Abstract

Paraquat intoxication is characterized by multi-organ failure, causing substantial mortality and morbidity. Many paraquat patients experience acute kidney injury (AKI), sometimes requiring hemodialysis. We observed 222 paraquat-intoxicated patients between 2000 and 2012, and divided them into AKI (<i>n</i> = 103) and non-AKI (<i>n</i> = 119) groups. The mortality rate was higher for AKI than non-AKI patients (70.1% vs. 40.0%, <i>P <</i> 0.001). Patients with AKI had a longer time to hospital arrival (<i>P</i> = 0.003), lower PaO₂ (<i>P</i> = 0.006) and higher alveolar-arterial O₂ difference (<i>P <</i> 0.001) 48 h after admission, higher sequential organ failure assessment 48-h score (<i>P <</i> 0.001), higher severity index of paraquat poisoning (SIPP) score (<i>P</i> = 0.016), lower PaCO₂ at admission (<i>P</i> = 0.031), higher PaO₂ at admission (<i>P</i> = 0.015), lower nadir PaCO₂ (<i>P</i> = 0.001) and lower nadir HCO₃ (<i>P</i> = 0.004) than non-AKI patients. Multivariate logistic regression indicated that acute hepatitis (<i>P <</i> 0.001), a longer time to hospital arrival (<i>P <</i> 0.001), higher SIPP score (<i>P</i> = 0.026) and higher PaO₂ at admission (<i>P</i> = 0.014) were predictors of AKI. The area under the receiver operating characteristic curve confirmed that an Acute Kidney Injury Network 48-hour score ≥ 2 predicted AKI necessitating hemodialysis with a sensitivity of 0.6 and specificity of 0.832. AKI is common (46.4%) following paraquat ingestion, and acute hepatitis, the time to hospital arrival, SIPP score and PaO₂ at admission were powerful predictors of AKI. Larger studies with longer follow-up durations are warranted.