Clinical Value Of NLR,CRP/Alb And Ca²⁺ In Severe Craniocerbral Injury Complicated With Early-onset Ventilator Pneumonia

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（s TBI）and early ventilator pneumonia（EOVAP）.Methods A total of 112 s TBI patients meeting the criteria were selected from the Third Affiliated Hospital of Anhui Medical University and The Intensive Care Unit（ICU）of Binhu Hospital from January 2018 to January 2020.According to the guidelines,patients were divided into EOVAP group（40 cases）and non-EOVAP group（72 cases）within five days of mechanical ventilation whether they were complicated by ventilator pneumonia,and the differences in NLR,CRP/Alb and serum Ca²⁺levels between the two groups were compared.Statistical logistic regression analysis and subject work characteristic curves were used to analyze the diagnostic value of their serological indicators for VAP,while univariate and multifactorial Cox proportional risk models were used to screen for prognostically significant indicators with a 28-day time cutoff to assess their prognostic ability in patients with s TBI.Results EOVAP was diagnosed in 40 of 112 s TBI patients（35.7%）.The most common bacterial strains were Staphylococcus aureus（22%）,Acinetobacter baumannii（20%）and Klebsiella pneumoniae（20%）.According to multifactorial logistic regression analysis,significant increases in peripheral blood NLR,CRP/Alb,and varying decreases in Alb and Ca²⁺levels were all independent risk factors for the development of EOVAP in patients with s TBI（P<0.05）.Subject working characteristic curve ROC results:the AUC for NLR diagnosis of s TBI concurrent with EOVAP was 0.814,with a best cut-off value of 8.17,a maximum sensitivity of 87.5%and a specificity of 63.9%.the AUC for CRP/Alb diagnosis of s TBI concurrent with EOVAP was 0.798,with a best cut-off value of 1.02,a sensitivity of 80.0%and a specificity of 73.6%.The AUC of serum Ca²⁺for the diagnosis of s TBI complicated by EOVAP was 0.853,with an optimal cut-off value of 2.0 mmol/L,sensitivity of 87.5%and specificity of 88.9%.The AUC of Alb for the diagnosis of s TBI complicated by EOVAP was 0.803,with an optimal cut-off value of 33.5g/L,sensitivity of 75%and specificity of 76.4%.Meanwhile Cox proportional risk regression model assessment analysis showed that NLR（OR=1.126,95%CI:1.072 to 1.181,P<0.01）and CRP/Alb（OR=2.652,95%CI:1.203～5.846,P=0.016）were risk factors for the patient’s 28-day prognosis.The28-day survival curve of the EOVAP group was lower than that of the non-EOVAP group.Conclusion NLR,CRP/Alb and hypocalcemia have high clinical diagnostic value in predicting EOVAP in s TBI patients.Meanwhile,NLR and CRP/Alb are closely related to the 28-day prognosis of patients,which deserve extensive clinical attention.