Utility of surveillance bacterial cultures in neonatal exchange blood transfusions

Invasive procedures, like exchange blood transfusions via the umbilical vein, potentially expose the neonate to nosocomial infection. Attempts to limit hospital-acquired infection following exchange transfusions (ETF) in our unit have included umbilical vein blood cultures and swabs from umbilical stumps. The value of this surveillance was examined. Forty-four neonates undergoing ETF were studied prospectively. Specimens for bacterial cultures were taken from the umbilical stump and umbilical vein immediately before and after ETF and results correlated with clinical outcome and antibiotic use. Except for staphylococci, bacteria cultured in the asymptomatic neonates were similar to those cultured from neonates who had signs of infection. Polymicrobial cultures were obtained from both umbilical vein blood and stump specimens suggesting contamination with colonizing organisms. Surveillance bacterial culture results did not influence antimicrobial therapy. Therefore, we advocate microbiological investigations only when clinical infection is suspected.