Nosocomial bloodstream infections in neurosurgery: a 10-year analysis in a center with high antimicrobial drug-resistance prevalence.

BACKGROUND

Data on nosocomial bloodstream infections (NBSI) in neurosurgery is limited. This study aimed to analyze the epidemiology, microbiology, outcome, and risk factors for death in neurosurgical patients with NBSI in a multidrug resistant setting.

METHODS

Neurosurgical patients with a confirmed NBSI within the period 2003-2012 were retrospectively analyzed. NBSI was diagnosed when a pathogen was isolated from a blood sample obtained after the first 48 h of hospitalization. Patients' demographic, clinical, and microbiological data were recorded and analyzed using univariate and multivariate analysis.

RESULTS

A total of 236 patients with NBSI were identified and 378 isolates were recovered from blood cultures. Incidence of NBSI was 4.3 infections/1000 bed-days. Gram-negative bacteria slightly predominated (54.5 %). The commonest bacteria were coagulase-negative staphylococci (CoNS, 26 %), Klebsiella pneumoniae (15.3 %), Pseudomonas aeruginosa (14.8 %), and Acinetobacter baumannii (13.2 %). Carbapenem resistance was found in 90 % of A. baumannii, in 66 % of P. aeruginosa, and in 22 % (2003-2007) to 77 % (2008-2012) of K. pneumoniae isolates (p < 0.05). Most CoNS and Staphylococcus aureus isolates (94 and 80 %, respectively) were methicillin-resistant. All Gram-negative isolates were sensitive to colistin and all Gram-positive isolates were sensitive to vancomycin and linezolid. Antimicrobial consumption decreased after 2007 (p < 0.05). Overall mortality was 50.4 %. In multivariate analysis, advanced age and stay in an Intermediate Care Unit (IMCU) were independent risk factors for in-hospital mortality (p < 0.05).

CONCLUSIONS

Overall, high incidence of NBSI and considerable resistance of Gram-positive and particularly Gram-negative bacteria were noted in neurosurgical patients. Mortality was high with advanced age and stay in IMCU being the most important death-related factors.