When to Stop Antibiotics in Clinically Suspected Neonatal Sepsis with a Negative Blood Culture?,SULIMAN H. AL-FIFI, WALID M. ABDEL WAHAB, MUFAREH H. ASIRI, MANSOUR Y. OTAIF, HIND M. AHMED and FUAD E. ABBAG
Abstract
Objectives: To determine the time for detection of positive blood cultures obtained from newborn infants admitted with suspected sepsis and to decrease unnecessary exposure to antibiotics.
Methods: We retrospectively evaluated all positive blood cultures obtained from newborn infants with suspected sepsis admitted to Neonatal intensive care unit (NICU) and Pediatric medical ward (PMW), Aseer Central Hospital between January 2004 and December 2008 using the automated culture machine.
Results: 538 (62.3%) of the isolates were assessed as true pathogens (491 bacteria and 47 fungi) and 326 (37.7%) isolates were considered to be contaminants. Of the 491 true bacterial pathogens, 367 (75%) were initial blood cultures and 124 (25%) were follow-up blood cultures. The overall time for blood cultures to become positive was 16.3±8.5hr. We found no significant difference between the time to positivity of the early-onset (14.4±5.6hr) and that of late-onset (15.9±7.5hr) initial bacterial isolates, p=0.1. Of early-onset initial blood cultures 98% were positive within 24hr and 100% by 36hr. Of late-onset initial blood cultures 98% were positive within 36hr and 100% by 45hr. Cultures growing Gram-positive and Gram-negative organisms became positive by 24 to 36hr. Forty-seven fungal isolates were detected and the time to pos-itivity was 22±7hr.
Conclusions: We recommend discontinuation of antibiotics by 24 to 36hr in infants with possible early-onset sepsis and by 48hr among those with suspected late-onset sepsis who remain clinically well and have negative blood cultures.