Predictive value of neutrophil-to-lymphocyte ratio in 30-day mortality of patients with acute paraquat poisoning

Abstract

Objective: To investigate the predictive value of neutrophil-to-lymphocyte Ratio (NLR) in 30-day mortality of patients with acute paraquat poisoning. Methods: We respectively reviewed the clinical parameters of 115 patients with acute paraquat poisoning. They were divided into survival (n=64) and non-survival (n=51) groups based on their 30-day outcome. Multivariate logistic regression was performed to identify risk factors of 30-day mortality. Receiver operating curve (ROC) test was applied to analysis to the predictive value of NLR in 30-day mortality ofacute paraquat poisoning patients. The correlations between NLR and severity index of paraquat poisoning (SIPP) were analyzed using Spearman's rank correlation coefficient. Results: Of the 115patients included in the study, 54 (46.96%) patients were males and 61 (53.04%) were females with a mean age of 38.96±13.58 years. The total mortality in 30-day was 44.35% (51/115) . The NLR at admission was an independently risk factor of 30-day mortality of patients with acute paraquat poisoning (OR 1.477, 95%CI 1.035-2.107, P<0.05) . The NLR to predict the death of the area under the ROC curve was 0.894 (95%CI: 0.8212-0.9663, P<0.01) ; the optimal cutoff threshold was 11.71; the sensitivity was 71.79% and the specificity was 94.29%; the positive predictive value was 93.33%and negative predictive value of 75.00%. Meanwhile, the positive likelihood ratio was 12.57 and the negative likelihood ratio was 0.30. The NLR was significantly associated with SIPP (Spearman rho 0.525; P<0.01) and it was significantly higher in patients with SIPP of ten or higher than in those with an SIPP less than 10 (15.02±12.40 vs. 6.19±2.54, P<0.05) . Conclusion: The increased NLR at admission was an independently risk factor of 30-day mortality of patients with acute paraquat poisoning and it was significantly correlated with SIPP score. Therefore, NLR was useful for predicting prognosis of patients with acute paraquat poisoning.