Clinical Characteristics And Risk Factors Of Nosocomial Infection In Patients Undergoing Neurosurgical Operation

Objective：To investigate the prevalence and risk factors of nosocomial infections(NI) ofintracranial infection in patients undergoing neurosurgical operation by using thedescriptive and analytical epidemiologic methods, and provide theoretical basisforpreventing nosocomial infections.Methods：1. We collected retrospectively the clinical data of3520patients who were underwentneurosurgical operation form December2007to November2012in a tertiary teachinghospital of Yunnan Provine, China, by using a self-designed form. The clinicaldataincluded the characteristics of patients, the operation situation and the situation ofnosocomial infections, the described epidemiological characteristics of nosocomialinfection and analysis of risk factors.2. A1:2matched case-control study was carried outincluding202cases and404controls. The risk factors were analyzed by Chi-squaretes, t test and Logistic regressionmodel using SPSS13.0.Result：1. A total of3520patients had been investigated from2007to2012. There were59.40%were male and40.60%female with average age was42.52±19.69years. Therewere632patients and681case-times suffered from nosocomial infection, the infection ratewas17.95%, the infection case-time rate was19.34%and the incidence density was7.51‰.The nosocomial infection rate and the infection case-time rate and the incidence densityshowed a downward trend in general from2007to2012. The differences had statisticalsignificance(P＜0.05) by the incidence rate of nosocomial infection,.2. Nosocomial infection sites were successively the surgical site infection in259cases(38.03%), the lower respiratory tract infection in243cases (35.68%), the urinary tractinfection in76cases (11.16%), the gastrointestinal tract infection in53cases (7.78%), the upper respiratory tract infection in34cases (4.99%), the blood infection in11cases(1.62%), the oral infection in4cases (0.59%), and the skin and soft tissue infection in1cases (0.15%).3. The259cases with surgical site infections were found among the3520patients andthe infection rate was7.36%. Organ/space infection (intracranial infection) were found in202cases (77.99%), superficial incision in45cases (17.37%), deep incision in12cases(4.63%). Surgical site infections mainly occured in3-30days (average8days) aftersurgery. The nosocomial infection rate and incidence density increased with the the rise ofNNIS score. SSI group prolonged hospital stay14days than non SSI group. The days ofhospitalization has a relationship with NNIS score; with the increasing of NNIS score, theSSI groups had increasing hospital stay times with1.4days,3.2days and5.8dayscomparedwith the NNIS0.4. There were437strains of pathogenic bacteria detected from the632infectionedpatients. The318Gram-negative bacilli had been isolated (72.99%) among thesepathogenic bacteria; the first rank was Klebsiella pneumoniae, followed by Acinetobacterbaumannii, Escherichia coli. Ninety-five Gram--positive bacilli had been isolated(21.74%); the first rank was Staphylococcus aureus, followed by Staphylococcusepidermidis, Staphylococcus haemolyticus. Twenty-four strains of fungi had been isolated(5.49%).5. Univariate analysis showed that the nosocomial infection of patients undergoingneurosurgical operation was related to age, primary disease, basic disease, hospital stay,hospitalization time before operation, the duration of operation, a second operation,preoperative hyperglycemia, blood transfusion, glucocorticoid, gastricacid inhibitor,tracthealintubation/tracheotomy (P <0.05). There were no statistical significance amongpatients gender, white blood cells before operation(P>0.05). There was statisticalsignificancebetween surgical site infections of neurosurgical operation and index scores ofrisk factors. Multivarite logistic regression analysis showed that age over60, the durationof operation over4h, a second operation, preoperative hyperglycemia, blood transfusion,tracthealintubation/tracheotomy, neurologic tumors and cerebrovascular diseases wereindependent risk factors for infection in the patients undergoing neurosurgical operation.6. Univariate analysis showed that the related risk factors for intracranial infection were primary disease, operative approach, NNIS score, hospitalization time beforeoperation, the duration of operation, a second operation, blood transfusion andpostoperative cerebrospinal fluid leakage(P <0.05). Multivarite logistic regression analysisshowed that neurologic tumors(OR=2.074，95%CI:1.106～3.890), infratentorial operationapproach(OR=5.722，95%CI:3.794～8.630), operation time more than4hours(OR=3.184，95%CI:1.441～7.033), a second operation(OR=2.230，95%CI:1.009～4.928),postoperative cerebrospinal fluid leakage(OR=4.623，95%CI:2.013～10.618) were riskfactors for intracranial infection.Conclusion：1. The incidence density was used to measure the strength of nosocomial infection, sothe effect of the incidence of nosocomial infection caused by the hospitalization time wereeliminated, the accuracy and validity of study conclusion were enhanced, and it wereconfirmed that the incidence density was necessary and feasible in nosocomial infectionmonitoring.2. The incidence of nosocomial infection with patients undergoing neurosurgicaloperation was high, however the nosocomial infection rate and he infection case-rate andthe incidence density showed a downward trend in general form2007to2012, theincidence rate of nosocomial infection, the difference had statistical significance, thisillustrates the prevention and control work of nosocomial infection in the patientsundergoing neurosurgical operation had achieved some success.3. The main type of infection were the surgical site infections and the lower respiratorytract infection and measures would be taken to prevent and control intervention combined.4. The surgical site infections were mainly found among intracranial infection.Surgical site infections mainly occured in about8days after the operation. The nosocomialinfection rate and incidence density increased Along with the increase of NNIS score. SSIgroup than that in non SSI group prolonged hospital stay14days. The days ofhospitalization has a relationship with NNIS score; the SSI group increased hospital staywas1.4days,3.2days and5.8days with the increase of NNIS score, compared with theNNIS0.5. The incidence of nosocomial infection with patients undergoing neurosurgicaloperation was significantly associated with age over60, the duration of operation over4h, a second operation, preoperative hyperglycemia, blood transfusion, tracthealintubation/tracheotomy, neurologic tumors and cerebrovascular diseases.6.The occurrence of postoperative intracranial infection in neurosurgery wasassociated with multiple factors, such as, neurologic tumors, infratentorial operationapproach, operation time more than4hours, a second operation, postoperativecerebrospinal fluid leakagewere risk factors for postoperative intracranial infection inneurosurgery.