Abstract: Objective To evaluate the value of neutrophil to lymphocyte ratio（NLR），C⁃reactive protein to albumin ratio（CRP/Alb），and serum calcium ion（Ca2 +）levels in patients with severe craniocerebral injury （TBI）and early ventilator pneumonia（EOVAP）. Methods 112 sTBI patients who met the standard in the Third Affiliated Hospital of Anhui Medical University from January 2018 to January 2020 were selected and divided into EOVAP group（40 cases）and non ⁃ EOVAP group（72 cases）according to whether they were complicated with pneumonia. Differences in NLR，CRP/Alb，and Ca2+ levels between the two groups were compared. Logistic regres⁃ sion analysis and subject work characteristic curve were used to analyze the diagnostic value. The Cox proportional hazards model assesses the prognosis of patients after the 28⁃day cutoff. Results According to multivariate Logistic regression analysis，significant increases in peripheral blood NLR，CRP/Alb，and decreases in Alb and Ca2+ levels were independent risk factors for EOVAP（P < 0.05）. The ROC curve showed that the AUC of NLR and CRP/Alb in diagnosing sTBI combined with EOVAP was 0.814 and 0.798，significantly better than Alb and Ca2+ . Cox propor⁃ tional hazard regression model evaluation analysis showed that：NLR（OR = 1.126，95% CI：1.072~1.181，P < 0.01）and CRP/Alb（OR = 2.652，95%CI：1.203 ~ 15.846，P < 0.01）is a risk factor for the prognosis of patients at 28 days. Conclusion NLR，CRP/Alb，and hypocalcemia have high clinical diagnostic value in predicting EOVAP complication in sTBI patients，and NLR and CRP/Alb are closely related to the prognosis of patients at 28 days，which are worthy of extensive clinical attention.

Key words:

neutrophil to lymphocyte ratio, C?reactive protein, albumin, serum calcium, severe traumatic brain injury, ventilator?associated pneumonia