title: Peritoneal phosphate removal varies by peritoneal dialysis regimen: an underestimated parameter of phosphate control.
abstract: BACKGROUND
  The optimization of phosphate (P) removal by peritoneal dialysis (PD) is often underestimated. Our objective was to investigate peritoneal P clearance and its relationship with standard adequacy targets, hyperphosphatemia and automated PD (APD) parameters.
  
  
  METHODS
  Dialysis dose, P clearances (24-hour urine and effluent samples), estimated percentage of diffusive P removal and peritoneal transport rate (PET) were evaluated in 77 adult prevalent PD patients.
  
  
  RESULTS
  Total P removal strongly correlated with residual renal function parameters, dissociated from peritoneal Kt/V urea (r=-0.36; p=0.02) and creatinine clearance (r=-0.32; p<0.0001). A correlation of P clearance with net ultrafiltration was not found. Among the variables studied, only renal and peritoneal P clearances were significantly lower in hyperphosphatemic patients. In APD, peritoneal phosphate clearance was positively correlated with 4-hour dialysate to plasma creatinine ratio (r=0.46; p=0.039). Slow transporters had higher peritoneal P clearances under continuous ambulatory PD (CAPD) regimens. Hyperphosphatemia was significantly associated with a lower number of APD cycles and shorter nightly therapy time, with insufficient dwell time individualization.
  
  
  CONCLUSIONS
  P peritoneal clearance is a modifiable parameter of P control in PD regimens and an additional adequacy target. Prescription skills are recommended in APD patients, particularly in anurics, to take into account peritoneal transport rate.
authors.affiliation: Department of Nephrology, CHP - Santo António Hospital, Porto, Portugal.
authors.forename: Carlos
authors.initials: C
authors.lastname: Botelho
authors.forename: Anabela
authors.initials: A
authors.lastname: Rodrigues
authors.forename: Jose Carlos
authors.initials: JC
authors.lastname: Oliveira
authors.forename: António
authors.initials: A
authors.lastname: Cabrita
mesh_terms: D000328:Adult; D000368:Aged; D001002:Anuria / Q000097:blood / Q000150:complications; D003404:Creatinine / Q000097:blood / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D054559:Hyperphosphatemia / Q000097:blood* / Q000209:etiology; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D010529:Peritoneal Cavity; D010530:Peritoneal Dialysis / Q000379:methods*; D010531:Peritoneal Dialysis, Continuous Ambulatory; D010710:Phosphates / Q000097:blood / Q000378:metabolism*; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000150:complications / Q000628:therapy*; D013997:Time Factors; D014462:Ultrafiltration
chemical_list: D008567:Membranes, Artificial; D010710:Phosphates; D003404:Creatinine