Analysis Of Risk Factors For Surgical Site Infection After Posterior Lumbar Spine Surgery

Objective:To analyze the rate of postoperative surgical site infection and to identify the independent risk factors after posterior lumbar spine surgery.Methods:The clinical data of 2715 patients who underwent posterior surgery for lumbar spinal disease from January 2010 to August 2016 were retrospectively analyzed.It included 1075(39.60%)cases of lumbar disc herniation,611(22.50%)cases of lumbar spondylolisthesis,580(21.36%)cases of lumbar spinal stenosis,449(16.54%)cases of lumbar vertebral fracture.We matched with three non surgical site infected patients by sex,body mass index and major diagnosis from the database of patients with posterior lumbar spine surgery and defined as the control group.Patients’ age,coexisting disease,surgical procedure,operation time,intraoperative blood loss,number of operative segments,preoperative and postoperative blood test,liver and kidney function tests,electrolyte and postoperative drainage time were also recorded and analyzed.We analyze our dates by SPSS19.0 statistical software.The continuous variable were analyzed by t test and the categorical variables were compared with X2 test or Fisher exact test.Multivariate logistic regression analysis was used to determine the statistically significant variables for each candidate risk factor from single factor analysis,and the difference was statistically significant with P <0.05.Results:The 64 cases(2.36%)patients had surgical site infection,there were 46 males and 18 females who aged 27-77 years old.The operative age was 58.30 ± 10.44 years old.The original disease from infection group was 18 cases of lumbar disc herniation,11 cases of lumbar spondylolisthesis,21 cases of lumbar spinal stenosis,14 cases of lumbar vertebral fracture.The single factor analysis showed that: preoperative diabetes mellitus,preoperative factors include erythrocyte,hemoglobin,total protein,albumin,serum calcium,glucose;surgical methods,operation time,anesthesia time,number of operative segments,intraoperative blood loss,ASA;the postoperative factors include erythrocyte,hemoglobin,albumin,globulin,platelet,serum calcium and extubation time was statistically significant(P <0.05).Further logistic regression analysis showed that preoperative diabetes mellitus(OR = 2.488,P= 0.020),preoperative lower albumin(OR = 0.863,P = 0.017),preoperative lower serum calcium(OR = 0.018,P = 0.007),the increased number of operative segments(OR = 2.329,P = 0.000),postoperative lower hemoglobin(OR = 0.950,P = 0.008),postoperative lower albumin(OR = 0.897,P = 0.035),postoperative higher globulin(OR = 1.082,P = 0.008)and delay pull out drainage tube time(OR = 1.493,P =0.016)were independent risk factors for postoperative surgical site infection.Conclusions:Diabetes mellitus,preoperative factors including lower albumin and lower serum calcium,number of operative segments;postoperative factors including decreasing hemoglobin,lower albumin,high globulin and delay pull out drainage tube time were independent risk factors for postoperative surgical site infection.To prevent lumbar surgical site infection from occurring.We should not only pay attention to the treatment of coexisting disease but also monitoring of hemoglobin,albumin,globulin and electrolyte changes.