Hospital-acquired meningitis in patients undergoing craniotomy: incidence, evolution, and risk factors

OBJECTIVES: To establish the incidence of postcraniotomy meningitis, identify etiologic agents, assess patients' medical progress in relation to both length of hospitalization and mortality, and analyze risk factors. MATERIAL AND METHODS: This study was developed at Hospital S?o Paulo, a tertiary university hospital, between August 1995 and January 1998. We conducted a case-control trial, in which 50 pairs of patients were matched. RESULTS: An 8.9%-postcraniotomy meningitis incidence was found. Gram-negative bacilli were the most common etiologic agents isolated. Mortality among the patients was 30%. Mean hospital stay for the patients was 42.9 +/- 22.1 days; for the controls, mean hospital stay was 19.0 +/- 11.4 days (P =.00001). Although several risk factors were identified by univariate analysis, including postoperative external ventricular shunt (OR = 2.92, CI 95% = 1.245-6.865, P =.014), remote site infection (OR = 2.85, CI 95% = 0.995-8.173, P =.051), and repeat operation (OR = 5.02, CI 95% = 1.569-16.066, P =.007), only repeat operation remained in the multivariate analysis model (OR = 3.68, CI 95% = 1.158-11.700, P =.027). CONCLUSION: Postcraniotomy meningitis resulted in a high mortality rate and a longer hospital stay, with repeat operation identified among the risk factors.