| Objective:To investigate the changes of white blood cells,neutrophils,lymphocytes,neutrophil lymphocyte ratio and C-reactive protein in posterior lumbar fusion and its clinical value in the diagnosis of early incision deep infection.Contents and Methods:1.Through the electronic inpatient medical record system,the information of patients who were diagnosed as lumbar spinal stenosis,lumbar disc herniation,lumbar spondylolisthesis and underwent open posterior lumbar interbody fusion in the Department of Spinal Surgery,the First Affiliated Hospital of Dali University from January 1,2017 to December 31,2021 was retrieved(a total of 981 cases).The surgical site infection was confirmed by secondary surgical debridement during a single hospitalization as the infection group(a total of 15 cases),and the non-surgical site infection occurred after posterior lumbar interbody fusion during the same period as the non-infection group(a total of 280 cases).2.White blood cells,percentage of neutrophils,absolute value of neutrophils,percentage of lymphocytes,absolute value of lymphocytes and C-reactive protein were collected before and after operation.Postoperative inflammatory indicators were collected at 1-3days after surgery,4-6 days after surgery,7-9 days after surgery,and 10-15 days after surgery,and the neutrophil lymphocyte ratio was calculated at the corresponding time period.3.SPSS 26.0 software was used to compare and analyze the inflammatory index data of the two groups of patients.All measurement data were expressed as mean±standard deviation((?)±S),t test and repeated measurement analysis of variance were used.The classified data were expressed as%,and chi-square test was used.The difference was statistically significant with P<0.05.Graph Pad software was used to make the contour map of the level change trend of relevant indicators.By drawing the receiver operating characteristic curve(ROC),the area under the ROC curve(AUC)was used to predict the diagnostic value of inflammatory markers.Results:1.A total of 295 people were included in this study,including 15 people in the infection group,6 males and 9 females;there were 280 people in the non-infected group,132 males and 148 females,with an overall infection rate of 5%.There was no statistical difference in gender between the infected group and the non-infected group(P>0.05).2.The total number of white blood cells in the uninfected group showed a trend of rapid increase to the peak at 1-3 days after surgery,gradually decreased at 4-6 days after surgery,and increased again at 7-9 days and then gradually decreased to normal levels.The infection group showed a rapid increase 1-3 days after surgery,but the peak level was lower than that of the non-infection group.It gradually decreased 4-9 days after surgery and increased again 10-15 days after surgery.The total number of white blood cells on the 1-3 days and 7-9 days after operation,the data were statistically analyzed.The difference between the uninfected group and the infected group was statistically significant(P<0.05).The total number of white blood cells in the uninfected group was higher than that in the infected group.On the 4th-6th day and the 10th-15th day after operation,there was no significant difference between the uninfected group and the infected group(P>0.05).The AUC of 10-15 days after operation was 0.555,suggesting that there was diagnostic value.When the total number of white blood cells>7.815×10~9/L,there may be infection,with sensitivity of 84.2%and specificity of 35.4%,but the diagnostic value was low.3.The percentage of neutrophils and the absolute value of neutrophils in the uninfected group and the infected group showed a similar overall change trend,both of which showed a trend of rapid increase and then slow decrease after operation.The infection group increased again before the diagnosis of SSI.The percentage of neutrophils on the1-3 days,4-6 days,7-9 days,and 10-15 days after surgery,the data were statistically analyzed.There was no significant difference between the uninfected group and the infected group at each corresponding time period(P>0.05).The AUC value was the largest at 10-15 days after operation,which was 0.696,suggesting that it had certain diagnostic value.When the percentage of neutrophils was>75.325%at 10-15 days after operation,infection could be considered,with a sensitivity of 57.9%and a specificity of83.9%.The absolute value of neutrophils in the uninfected group and the infected group was(9.85±3.27)×10~9/L VS(8.99±3.32)×10~9/L,(7.73±2.68)×10~9/L VS(7.7±2.65)×10~9/L,respectively,on the 1-3 days and 7-9 days after operation.The data were statistically analyzed.The difference between the uninfected group and the infected group was statistically significant(P<0.05),indicating that the absolute value of neutrophils in the uninfected group was higher than that in the infected group on the 1-3 days and 7-9 days after operation.ROC curve analysis showed that the AUC of 1-3 days and 7-9 days after operation were 0.578 and 0.500,respectively,which suggested that the diagnostic value was relatively low.On the 4-6 days and the 10-15 days after operation,there was no significant difference between the uninfected group and the infected group(P>0.05).The AUC value was the largest at 10-15 days after operation,which was 0.618,suggesting that there was diagnostic value.When the absolute value of neutrophils was>8.14×10~9/L,infection could be considered.The sensitivity was 31.6%and the specificity was 90.7%,but the diagnostic value was relatively low.4.The percentage of lymphocytes and the absolute value of lymphocytes in the uninfected group and the infected group showed the same trend,both of which decreased immediately after surgery and then slowly recovered.The mean percentage of lymphocytes and the absolute value of lymphocytes on the 1-3 days,4-6 days,7-9 days,10-15 days after operation,the data were statistically analyzed.There was no significant difference between the uninfected group and the infected group(P>0.05).According to ROC curve analysis,the AUC value of lymphocyte percentage was the largest at 10-15days after operation,which was 0.689,suggesting that it had certain diagnostic value.When the lymphocyte percentage was less than 13.568%,infection could be considered,with sensitivity of 57.9%and specificity of 86.4%.The AUC value of lymphocyte absolute value was the largest at 10-15 days after operation,which was0.655,suggesting that it had certain diagnostic value.When the absolute value of lymphocyte was less than 1.002×10~9/L,infection could be considered,with sensitivity of42.1%and specificity of 93.9%.5.The neutrophil lymphocyte ratio(NLR)of the uninfected group and the infected group showed a rapid increase and then a slow decline after the operation,and the infected group increased again before the diagnosis of SSI.The level of neutrophil lymphocyte ratio(NLR)on the 1-3 days,4-6 days,7-9 days and 10-15 days after operation,the data were statistically analyzed.There was no significant difference between the uninfected group and the infected group at each corresponding time period(P>0.05).ROC curve analysis showed that the AUC value of neutrophil lymphocyte ratio(NLR)was the largest at 10-15 days after operation,which was 0.681,suggesting that it had certain diagnostic value.Infection could be considered when neutrophil lymphocyte ratio>5.671,with sensitivity of 57.9%and specificity of 88.6%.6.The C-reactive protein in the uninfected group and the infected group showed a gradual upward trend after surgery.The C-reactive protein in the uninfected group peaked at 7-9days after surgery and gradually decreased at 10-15 days after surgery,while the C-reactive protein in the infected group remained at a high level at 4-9 days after surgery and increased again at 10-15 days after surgery.The level of CRP in the uninfected group was lower than that in the infected group on the 4-6 days and 10-15 days after operation.The mean values were 33.22±33.06mg/L VS 53.42±60.36mg/L,21.9±20.55mg/L VS 63.51±40.11mg/L,respectively.After statistical analysis,the difference was statistically significant(P<0.05).ROC curve analysis showed that the AUC of 4-6 days after operation and 10-15 days after operation were 0.629 and 0.811,respectively,suggesting diagnostic value,but the diagnostic value of 10-15 days after operation was higher.When C-reactive protein was greater than 41.282mg/L,infection could be considered,with sensitivity of 73.7%and specificity of 83.9%.On the 1-3 days and 7-9 days after operation,there was no significant difference between the uninfected group and the infected group(P>0.05).Conclusions:1.The leukocyte numbers,neutrophils and lymphocytes in the early postoperative period(1-9 days)were less than normal,which was one of the causes of postoperative incision infection.2.The incidence of SSI should be considered when the percentage of neutrophils,CRP and NLR remained high or gradually increased at 10-15 days after operation.3.The possibility of SSI should be considered when the percentage of lymphocytes continues to decrease at 10-15 days after surgery. |
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