Use of the antimicrobial removal device prior to blood culture in patients on antibiotic therapy.

The efficacy of the antimicrobial removal device in facilitating isolation of bacteria from blood containing antibiotics was evaluated in a multicenter study. Blood specimens from 143 patients who had culture-proven septicemia and had been on antibiotic treatment for at least 24 hours were recultured with and without the aid of the device. Septicemia persisted in 33 of the patients and use of the device improved the isolation rates: 63% of the gram-positive bacteria and 32% of the gram-negative bacteria were isolated only with the aid of the device. Use of the device was an advantage in 10 of 13 cases where the antibiotic concentration in the bottles exceeded the MIC for the infecting microorganism but in only 5 of 19 cases where the concentration was lower than the MIC. It is concluded that the antimicrobial removal device may be useful in patients already on antibiotic treatment, but that its use is limited by the cost and the amount of work involved.