Comparison of peritoneal fluid culture results from adults and children undergoing CAPD

Background: Peritonitis is a common complication in patients with end-stage renal disease treated by continuous ambulatory peritoneal dialysis (CAPD). Empirical treatment is based on the organisms that are most frequently iso lated and their susceptibilities. Objective:To analyze and then compare peritoneal fluid culture results from adult and pediatric patients on CAPD, with respect to micro-organisms and antimicrobial susceptibilities. Design:Three-year retrospective review of peritoneal fluid cultures from ad ults and children on CAPD. Results:We isolated 481 organisms from 378 peritoneal fluid specimens, coll ected from 135 patients (45 children, 90 adults). There were 191 episodes o f peritonitis in children (mean 4.2 +/- 3.5, range 1 - 15) compared to 187 in adults (2.1 +/- 1.9, range 1 - 10) (p < 0.001). Two or more episodes occ urred in 30 of 45 children (67%) compared to 33 of 90 adults (37%) (p < 0.0 01). The number of different organisms/patient as well as the total number of isolates/patient were significantly greater in children (respectively, 2 .8 +/- 2.3, range 1 - 12; and 5.3 +/- 5.2, range 1 - 27) than in adults (2. 0 +/- 1.3, range 1 - 6; and 2.7 +/- 2.4, range 1 - 10) (p < 0.005). After S taphylococcus epidermidis, S. aureus was the most frequently isolated organ ism, occurring in 18% of episodes in adults and 12% of episodes in children (p< 0.01). Twenty-two of 33 fungal isolates (67%) in children were Candida parapsilosis compared to 3 of 24 (12%) in adults (p < 0.001). Subanalysis of multiple episodes revealed that Pseudomonas and Candida occurred signifi cantly more often in children (p < 0.01), whereas S. aureus occurred more o ften in adults (p < 0.001). in polymicrobial episodes S. epidermidis occurr ed more often in adults (p < 0.05). Significant differences in susceptibili ties to ampicillin, ceftriaxone, chloramphenicol, and gentamicin were found between children and adults (p < 0.05 - 0.001). Conclusions: CAPD-associated peritonitis occurs significantly more often in children than adults. Significant differences in microbial etiology and su sceptibilities were found between pediatric and adult patients. Each dialys is unit should periodically analyze peritoneal fluid culture results from i ts CAPD patients. These data can then be used for optimization of empirical antimicrobial therapy of peritonitis.