Bacteremia Following Transurethral Instrumentation: The Predictive Value of a Serum Bactericidal Activity Test

Abstract

The bacteremic rate following transurethral instrumentation and the possibility of a serum bactericidal activity test to predict which patients that were at an increased risk of developing bacteremia was evaluated. Of 33 investigated patients, all elderly men, 14 underwent transurethral prostatic resection, 14 cystoscopy and 5 urethrotomy. None of the patients received prophylactic antibiotic treatment. The majority (97%) of the patients had bacteria isolated from the urinary tract before the instrumentation. Gram-positive cocci accounted for about two thirds (64%) and Gram-negative rods for about one third (31%) of all isolates. The most frequent species isolated were coagulase negative staphylococci (29%), Streptococcus faecalis (19%) and Klebsiella pneumoniae (12%). The bacteremic rate was 21%. None of the patients developed septicemia. Forty-four per cent of the patients with ≥10⁵ colony forming unitdm1 (cfu/ml) in urine developed bacteremia compared with 8% in patients with a sterile urine or less than 10⁵ cfu/ml in urine (p < 0.05). The urethral/prostatic flora was the source of bacteremia in at least one patient. Eighty-one per cent of the isolated strains were serum resistant. About half (54%) of the Gram-negative rods were more or less sensitive against actual, fresh patient serum. All Gram-positive cocci were resistant. There was no difference in the serum sensitivity between bacteria isolated from bacteremic patients and non-bacteremic patients. In conclusion, this study confirmed the relative high risk of developing bacteremia following transurethral instrumentation, especially if the urine is infected. The urethral and prostatic flora should not be ignored. Coagulase negative staphylococci should be thought of when antibiotic prophylaxis is given. The investigated serum bactericidal activity test could not predict the development of bacteremia. Other factors in the host defence system must be involved in the clearing of bacteria from blood