Optimal protocol for processing high-volume and Peds Plus blood cultures by the BACTEC NR860

The optimal incubation period for blood cultures collected in high-volume (Plus 26) and anaerobic (NR7A) media or Peds Plus medium and processed by the BACTEC NR860 was evaluated during a 12-month period. Organisms were recovered from 9% (1528 of 16,870) of blood culture vials (14% [1302 of 9118] of sets). Ninety-eight percent of positive vials were detected by day 5. Thirty-three vials (Plus 26 or NR7A) became positive on day 6 or 7; all positive Peds Plus vials were detected by day 5. Therapy did not change in response to detection of the organisms (26 "occasional" pathogens, 9 "usual" pathogens) in these vials. One usual pathogen had potential clinical significance, but the patient from whom the culture was collected died before it became positive. In the author's institution, the 5-day protocol for processing blood cultures could be adopted without compromising patient care.