Impact of the resin blood culture medium on the treatment of critically ill patients

Abstract

To assess the relevance, both clinical and bacteriologic, of the use of resin-containing blood culture media in blood cultures taken from critically ill patients receiving antibiotics. A prospective, open clinical trial. The mixed medical surgical intensive care unit (ICU) of a 550-bed urban hospital. All ICU patients admitted during a 3-month period (n = 49) with suspected sepsis requiring blood cultures as part of their laboratory investigations. The use of an aerobic resin-containing blood culture medium, in addition to the regular aerobic and anaerobic media for all blood cultures taken. Each blood culture result was classified as to its clinical significance. Changes in patient management were recorded. Culture sets in which the resin-containing bottle provided the information central to the change in patient management were identified. Bacteriologically, the results from the resin-containing medium were compared with the results from the aerobic and anaerobic media. Of 266 blood culture sets, 103 (39%) were positive, growing 278 bacterial and fungal isolates. Clinically, the resin-containing medium alone provided relevant data leading to changes in patient management on three occasions. On two of these occasions, cultures from the regular media provided the same data within 72 hrs. Bacteriologically, 77 (29%) aerobic bottles, 55 (21%) anaerobic bottles, and 89 (33%) resin-containing bottles were positive (statistical comparison of percentages: aerobic vs. resin-containing bottles, nonsignificant; aerobic vs anaerobic bottles, p < .046; anaerobic vs. resin-containing bottles, p < .0027). A similar proportion of pathogens was isolated from the resin-containing bottles only (9%) and aerobic bottles only (6%). A higher proportion of contaminants was isolated from the resin-containing bottles only than the aerobic bottles only in the various sets (17% vs. 7%, p < .046). The resin-containing bottle showed a trend toward increased detection of Staphylococcus aureus and Pseudomonas aeruginosa bacteremia. The resin-containing medium offers little clinical benefit to the majority of ICU patients. Bacteriologically, it seems to have a similar overall sensitivity as the regular aerobic medium (with the possible exception of a higher sensitivity for the isolation of S. aureus and P. aeruginosa), but a lower specificity. The wide-spread use of the resin-containing bottle cannot be recommended.