Predictive Value Of Neutrophil To Lymphocyte Ratio On Admission To Hospital For Stroke-associated Pneumonia And Poor Stroke Prognosis

Objective:Stroke-associated pneumonia(SAP)is one of the common complications of stroke,not only increasing the length of hospital stay and total hospital costs,leading to a poor prognosis,but also being an important cause of death and exacerbation.It is now thought that SAP may be associated with the onset of immunosuppression after stroke,which results in an imbalance in the immune system and an altered proportion of peripheral blood leukocyte components.As a novel inflammatory marker,the neutrophil-to-lymphocyte ratio(NLR)in the peripheral blood in the early post-stroke period has the advantage of being easy to detect and may be an objective and quantitative indicator of serum inflammation for clinical application in predicting and diagnosing SAP.In this article,the predictive and diagnostic value of SAP was investigated by a prospective case series approach to examine the levels of neutrophils and lymphocytes in peripheral blood,and the correlation with the occurrence of SAP and neurological deficits and poor prognosis after stroke.Methods:From April 2019 to December 2019,a total of 99 patients with acute stroke who were hospitalized in the Department of Neurology,the Second Affiliated Hospital of Kunming Medical University were collected.According to whether there was stroke-related pneumonia during hospitalization,the patients were divided into SAP group(31 cases)and non-SAP group(68 cases).The clinical data of the two groups were analyzed,including name,age,gender,history of hypertension,history of diabetes,history of stroke,NIHSS score of admission,etc.blood routine,blood lipid and fasting blood glucose were collected on the second day after admission,the ratio of neutrophils to lymphocytes(NLR)was calculated,and the patients were scored with mRS scale at discharge.The SPSS21.0 statistical software was used to analyze the collected data,in which the counts were expressed as frequencies and percentages,and the chi-square test was used for comparison between the two groups;the measures that met the normal distribution were expressed as mean ± standard deviation(x±s),the t-test was used for component comparison,and the one-way ANOVA was used for multi-group comparison;the measures that did not meet the normal distribution were expressed as median(25th-75th percentile)(M(Q25-Q75)),and the non-parametric test(Mann-Whitney U test)was used for comparison between the groups;Single factor analysis(P<0.05)was used as independent variable in risk factor analysis,and binary logistic regression analysis was carried out;the ROC curves were used to analyze the accuracy of the NLR prediction of SAP,and the best prediction cut-off value was selected using the Youden index.Pearson correlation wasused to evaluate the correlation between NLR and NIHSS score,and between NLR and mRS score.P<0.05 has statistical significance.Results:There were differences in age,history of stroke,swallowing dysfunction,use of acid depressants,retained gastric tube,NIHSS score,fasting glucose,neutrophil count,lymphocyte count,and NLR between SAP and non-SAP groups(P<0.05);the differences between SAP and non-SAP groups in sex,hypertension,hyperlipidemia,diabetes,ischemic heart disease,atrial fibrillation,smoking,alcohol consumption,heart failure,renal dysfunction,stroke type and stroke site,blood lipid level,and white blood cell count were not statistically significant(P>0.05).A dichotomous logistic regression analysis of possible risk factors for SAP showed that age,history of stroke,retained gastric tube,NIHSS score and hospital admission NLR were independent risk factors for SAP(P<0.05).The area under the ROC curve of SAP predicted by NLR is 0.764,with a 95%confidence interval of 0.658-0.813(P<0.05).When 4.32 is taken as the cutoff point of NLR prediction of SAP,the Youden index is the largest,with a sensitivity of 0.853 and a specificity of 0.613.NLR was positively correlated with NIHSS score after stroke(r=0.225,P<0.05),and NLR was higher in the severe neurological impairment group than in the moderate and mild neurological impairment groups(P<0.05).NLR was positively correlated with mRS score(r=0.159,P=0.116)and NLR was significantly higher in patients in the poor prognosis group than in the good prognosis group(P<0.05).Conclusions:Age,stroke history,NIHSS score,gastric tube retention,and NLR admission were independent risk factors for SAP during hospitalization.There is some predictive value for SAP when NLR>4.32.Admission NLR is positively correlated with the degree of neurological deficits,and high NLR may be associated with poor stroke prognosis.