Neurosurgical Infection Rates and Risk Factors: A National Surgical Quality Improvement Program Analysis of 132,000 Patients, 2006-2014

Background: The existing body of literature on postoperative neurosurgical infections lacks large multicenter reports on postoperative neurosurgical infections. This is the largest study to date of postoperative neurosurgical infections rates, time to event, and risk factors.

Methods: Demographics, medical history, and postoperative infections were assessed for all adult patients in the large, randomized, multicenter American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database undergoing an operation with a surgeon whose primary specialty was neurological surgery from 2006 to 2014.

Results: Of 3,723,797 cases from 517 institutions in the NSQIP from 2006 to 2014, 132,063 neurosurgery cases were identified. Within these patients, the 30-day rate of postoperative infections was 5.3%. Postoperatively, 1.8% of patients developed surgical site infections (SSI), and 3.9% developed other infections including pneumonia and urinary tract infections. Superficial SSI had a cumulative incidence of 0.8% at a median of 16 (interquartile range [IQR], 11-22) days. Pneumonia had a cumulative incidence of 1.4% at a median of 5 days (IQR, 2-10 days). Systemic inflammatory response syndrome had a cumulative incidence of 1.6% at a median of 3 days (IQR, 8-16 days). Predictors of postoperative infections on multivariable analysis included female sex, older age, obesity, functionally dependent status before surgery, ventilator dependence, preoperative steroid use, bleeding disorders, hyponatremia, lymphocytosis, anemia, thrombocytosis, emergent case status, wound class II-IV, American Society of Anesthesiologists class 3-5, and longer operative times.

Conclusion: The overall ACS-NSQIP reported rate of postoperative infections was 5.3% from 2006 to 2014. Multivariable analysis demonstrated several predictive factors for postoperative infections.