Analysis of Antibiotic Prophylaxis Practices Following Drain Insertion in Neurosurgery Patients

Introduction: Perioperative antibiotic prophylaxis prevents SSI, but prolonged post-operative prophylaxis when indwelling surgical drains remain in place remains controversial. Guidance for external ventricular drains supports brief (≤24 hours) antibiotic prophylaxis, but guidance does not exist for subgaleal or lumbar drains. We assessed whether prolonged antibiotic prophylaxis for subgaleal and lumbar drains prevents SSIs compared to brief prophylaxis.


Methods: This single-center, retrospective cohort study included adults admitted to the Neurocritical Care Unit at MGH between 01/2022-01/2024 with subgaleal or lumbar drains in place for >24 hours. Exclusions included antibiotics for active infections within 24 hours of drain placement, other drain types, surgery within 30 days prior, or history of C. difficile infection (CDI) or MDRO infections within 6 months. The primary outcome was a composite of SSI, CDI, and MDRO. Secondary outcomes included antibiotic practice patterns, 28-day antibiotic-free days, rates of antibiotic escalation, development of AKI, and ICU and hospital stay lengths.


Results: 475 patients were screened; 192 met the inclusion criteria. Mean age was 63.4 (±18.4) years; 71% were male. Common drain indications were SDH and TBI, each in 72 patients (38%). Median ICU stay was 4.4 days (IQR 2.0-11.0), drain duration was 3 days (IQR 2.2-4.9), and antibiotic duration was 2.3 days (IQR 1.2-3.78). 81% received cefazolin and 37% received vancomycin. SSI occurred in 4 (2.1%) patients, CDI in 5 (2.6%) patients, and MDRO developed in 47 (24.5%). Antibiotic prophylaxis duration was not associated with SSI development (OR 0.95, 95% CI 0.64-1.41); but was associated with increased odds of CDI per day of prophylaxis exposure (OR 1.14, 95% CI 1.01-1.28) and post-prophylaxis MDRO infection (OR 1.21, 95% CI: 1.07-1.36). Patients had a median of 25 (IQR 20-26) 28-day antibiotic-free days. AKI developed in 50 patients (26%). 86 patients (45%) had non-SSI infections, with 74/86 (86%) requiring antibiotic escalation.


Conclusions: Prolonged antibiotic prophylaxis after subgaleal and lumbar drain placement was not associated with a reduction in SSIs; longer durations of exposure were associated with increased CDI and MDRO infections. These findings support limiting prophylaxis to ≤24 hours.