—Dr Dalmau and coworkers have confirmed my findings (1) that the conventional method of ascitic fluid culture is less than 50% sensitive in detecting bacterial growth in patients with spontaneous bacterial peritonitis (SBP), and (2) that bedside inoculation of blood culture bottles with ascitic fluid essentially doubles the sensitivity. Dr Dalmau has not yet achieved statistical significance; I presume that he will achieve significance after the study of a few more patients.
Other investigators and practicing physicians from around the world have reported similar observations to me— when they change from the conventional culture method to the blood culture bottle method, their culture-positivity increases dramatically. The explanation is, at least in part, related to the low concentration of bacteria present in SBP. The median concentration of bacteria in ascitic fluid specimens that are diagnostic of SBP is two organisms per milliliter, according to my quantitative cultures (B.A.R., unpublished observations, 1987). The conventional