1148. Reduction of Blood Culture Contamination Rates by an Altered Sampling Protocol: Single-Center, Prospective, Randomized, Controlled, Open-Label Trial

Abstract

BackgroundContaminated blood cultures remain a challenge for patients, physicians, and microbiology laboratories, often leading to unnecessary antibiotic treatment. One approach to reduce contamination is to avoid culturing the initial blood sample that can contain a contaminated plug of skin from the needle stick. Initial specimen diversion technique (ISDT) was associated with decreased rate of blood culture contamination, when applied by trained phlebotomists, using either sterile vacuum blood collection tubes or a designated device. The aim of this study was to test ISDT in real-life, using externally nonsterile regular vacuum sample tubes for the diversion, by any medical personnel taking blood cultures.MethodsAdults from whom the treating physician planned to take blood cultures and additional blood chemistry tests, in the same venous puncture, were eligible and were randomly assigned to intervention or control arms. The hospital’s standard procedure for blood drawing was maintained, except that in the intervention arm, blood was aspirated to a green-capped tube, which was used for regular biochemistry tests, prior to the blood culture.ResultsFour hundred twenty-three blood cultures were obtained from 404 patients. Of 404 (11.1%) of the blood cultures, 45 yielded microbial growth, with 31 (7.7%) regarded as true pathogens and 14 (3.5%) as contaminants. Detection of true bloodstream infection was similar by the two methods, 16/181 (8.83%) with the ISDT, and 15/223 (6.72%) using the standard method. The ISDT was associated with a significantly less isolation of presumed contaminants compared with the standard method, 2/165 (1.2%) vs. 12/208 (5.76%), P = 0.02.ConclusionISDT, by any medical personnel, through altered order of test tube vs. blood culture sampling significantly reduced contamination of blood cultures without loss of diverted blood.Disclosures All authors: No reported disclosures.