title: Increased risk of Staphylococcus epidermidis peritonitis in patients on dialysate containing 1.25 mmol/L calcium.
abstract: Peritoneal macrophage function is decreased in vitro in the presence of dialysate with 1.25 mmol/L calcium compared with that containing 1.75 mmol/L calcium. Theoretically, patients using this dialysate may have a higher risk of peritonitis. Nineteen patients on continuous ambulatory peritoneal dialysis (CAPD) or continuous cycling peritoneal dialysis (CCPD) were converted from dialysate with 1.75 mmol/L calcium (mean time, 33 +/- 26 months) to that with 1.25 mmol/L calcium, for some or all exchanges (mean time, 10 +/- 4.7 months). Peritonitis rates were compared with 19 control patients who remained on dialysate with 1.75 mmol/L calcium. The two groups were matched for the proportion of diabetics, sex, age, use of the Y-set, and dialysis modality (CAPD, CCPD). Peritonitis rates were similar in the study patients before conversion to 1.25 mmol/L calcium dialysate and in the control patients (0.49 v 0.58 episodes/patient-year, respectively). After conversion to dialysate with 1.25 mmol/L calcium, the peritonitis rate was 0.82 episodes/patient-year contrasted to 0.58 episodes/patient-year in the control patients (P = 0.09). The peritonitis rate due to Staphylococcus epidermidis was 0.51 episodes/patient-year when 1.25 mmol/L calcium dialysate was used, and 0.19 episodes/patient-year for the comparable period in the control patients on 1.75 mmol/L calcium dialysate (P = 0.005). The proportion of peritonitis episodes due to S epidermidis increased from 20% to 61% after conversion to 1.25 mmol/L calcium (P = 0.01). The increased risk of peritonitis due to S epidermidis in patients using dialysate with 1.25 mmol/L calcium is consistent with a previous study demonstrating that clearance of S epidermidis by peritoneal macrophages is less effective with a decrease in the dialysate calcium content.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, University of Pittsburgh, PA.
authors.forename: B
authors.initials: B
authors.lastname: Piraino
authors.forename: J
authors.initials: J
authors.lastname: Bernardini
authors.forename: J L
authors.initials: JL
authors.lastname: Holley
authors.forename: J A
authors.initials: JA
authors.lastname: Perlmutter
mesh_terms: D000328:Adult; D002118:Calcium / Q000008:administration & dosage* / Q000032:analysis; D005260:Female; D015312:Hemodialysis Solutions / Q000737:chemistry*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000009:adverse effects* / Q000379:methods; D010531:Peritoneal Dialysis, Continuous Ambulatory / Q000009:adverse effects / Q000379:methods; D010538:Peritonitis / Q000453:epidemiology* / Q000209:etiology / Q000382:microbiology; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000209:etiology; D013212:Staphylococcus epidermidis
chemical_list: D015312:Hemodialysis Solutions; D002118:Calcium