RESUMO
The authors have developed a mathematical model for peritoneal dialysis, based on the Popovich-Pyle-Moncrief approach, that is capable of predicting urea Kt/V and total weekly creatinine clearance for a variety of peritoneal dialysis therapies. This prescription model incorporates both diffusive and convective solute removal as well as ultrafiltration and lymphatic absorption. The primary input to the model is a single peritoneal equilibration test. Twenty-four hour dialysate collection is not required. Results from an extensive prospective clinical study performed with 100 patients at five dialysis centers indicate that the model is valid for predicting urea Kt/V and creatinine clearance for continuous ambulatory peritoneal dialysis and continuous cycling peritoneal dialysis. Predicted clearances agree with the clinical data from these patients to within an average difference of approximately 10%. This model promises to be a powerful tool to assist nephrologists in quantifying the amount of peritoneal dialysis delivered by a given prescription, tailoring it to individual patient needs, and investigating the potential efficacy of a variety of alternative therapies.
Assuntos
Creatinina/urina , Modelos Biológicos , Diálise Peritoneal , Ureia/urina , Absorção , Adulto , Idoso , Transporte Biológico , Líquidos Corporais/metabolismo , Superfície Corporal , Água Corporal , Protocolos Clínicos , Feminino , Glicosúria , Humanos , Rim/metabolismo , Sistema Linfático/metabolismo , Masculino , Pessoa de Meia-Idade , Cavidade Peritoneal/fisiologia , Diálise Peritoneal Ambulatorial Contínua , Prescrições , Probabilidade , UltrafiltraçãoRESUMO
A clinical pilot study compared predictions of a new model of peritoneal dialysis mass transfer to measured weekly KT/V urea (KTu/V) and weekly creatinine clearance (Ccr) in liters per 1.73 m2 in 50 patients from five centers (40 CAPD, 10 CCPD). The Robertson et al. model is unique in that it does not require a 24-hour collection of dialysate. Instead, model predictions are based on the results of a standard 4-hour peritoneal equilibration test (PET) and appropriate demographic data. Analysis revealed 12 collection errors, 8 affecting the PET and 4 affecting 24-hour dialysate volume. PET drainage volume was low in six cases, excessive in two; 24-hour volume was incomplete in three, excessive in one. Similar errors were not found in the remaining 38 patients. In the 38 patients with correctly performed PET and dialysate collections, agreement between predicted and measured values was excellent.