EFFECT OF POSTMORTEM SAMPLING TECHNIQUE ON THE CLINICAL-SIGNIFICANCE OF AUTOPSY BLOOD CULTURES

Our objective was to investigate the value of postmortem autopsy blood cultures performed with an iodine-subclavian technique relative to th e classical method of atrial heat searing and antemortem blood culture s. The study consisted of a prospective autopsy series with each case serving as its own control relative to subsequent testing, and a retro spective survey of patients coming to autopsy who had both autopsy blo od cultures and premortem blood cultures. A busy academic autopsy serv ice (600 cases per year) at University of Texas Medical Branch Hospita ls, Galveston, Texas, served as the setting for this work. The inciden ce of non-clinically relevant (false-positive) culture results were co mpared using different methods for collecting blood samples in a prosp ective series of 38 adult autopsy specimens. One hundred eleven adult autopsy specimens in which both postmortem and antemortem blood cultur es were obtained were studied retrospectively. For both studies, posit ive culture results were scored as either clinically relevant or false positives based on analysis of the autopsy findings and the clinical summary. The rate of false-positive culture results obtained by an iod ine-subclavian technique from blood drawn soon after death were statis tically significantly lower (13%) than using the classical method of o btaining blood through the atrium after heat searing at the time of th e autopsy (34%) in the same set of autopsy subjects. When autopsy resu lts were compared with subjects' antemortem blood culture results, the re was no significant difference in the rate of non-clinically relevan t culture results in a paired retrospective series of antemortem blood cultures and postmortem blood cultures using the iodine-subclavian po stmortem method (11.7% v 13.5%). The results indicate that autopsy blo od cultures obtained using the iodine-subclavian technique have reliab ility equivalent to that of antemortem blood cultures. Copyright (C) 1 998 by W.B. Saunders Company.