Abstract： Objective:To investigate the predictive value of serum neuron axon guidance factor-1（Netrin-1）combined with bispectral index（BIS）for delayed encephalopathy in patients with carbon monoxide（CO）poisoning.Methods:A total of 128 patients with CO poisoning admitted to the First Hospital of Shanxi Medical University from January 2018 to November 2020 were prospectively selected as the subjects of this study，and they were divided into delayed encephalopathy after acute carbon monoxide poisoning（DEACMP）group（ n=53）and non-DEACMP group（ n=75），according to whether DEACMP occurred three months after discharge. Enzyme-linked immunosorbent assay was used to detect the patients’ serum Netrin-1 level，and the BIS value was calculated. The Netrin-1 and BIS at different time points in the two groups were compared，and the receiver operating characteristic（ROC）curve and area under the curve（AUC）of study subjects were used to evaluate Netrin-1，BIS，and Netrin-1 combined with BIS in predicting delayed encephalopathy in CO poisoning patients after receiving hyperbaric oxygen therapy. Multivariate logistic regression analysis was used to analyze the risk factors affecting delayed encephalopathy after CO poisoning. Results:The serum Netrin-1 levels and BIS values of the DEACMP group at 1，3，and 5 d after admission were significantly lower than those of the non-DEACMP group（ P<0.05）. The ROC curve results showed that the areas under the Netrin-1 and BIS curves were 0.785 and 0.810，respectively；the cut-off values were 395 and 62，respectively；the sensitivity were 70.62% and 78.69%；and the specificity were 77.85% and 86.64%，respectively. The AUC，sensitivity，and specificity of Netrin-1 combined with BIS were 0.896，85.69%，and 98.52%，respectively. Compared with using Netrin-1 or BIS alone，Netrin-1 combined with BIS was better in predicting delayed encephalopathy in CO poisoning patients after hyperbaric oxygen therapy. Multivariate logistic regression analysis showed that Netrin-1 < 395 ng/ml and BIS < 62 were the risk factors of delayed encephalopathy in CO poisoning patients after hyperbaric oxygen therapy（ P<0.05）. Conclusion:Netrin-1 and BIS are reduced in DEACMP patients，and BIS combined with Netrin-1 has significant clinical value in predicting the occurrence of delayed encephalopathy in CO poisoning patients after hyperbaric oxygen therapy.