RESUMEN
Preservation of residual renal function (RRF) is an important goal. In children, a more rapid decline in RRF has been observed under hemodialysis (HD) therapy as compared with peritoneal dialysis (PD) therapy. In adults, however, automated peritoneal dialysis (APD) may cause a more rapid decline of RRF than continuous ambulatory peritoneal dialysis (CAPD) does. The objective of the present study, a survey in a single center over the last 15 years, was to assess the impact of APD versus hemodiafiltration (HDF) on daily urinary volume (dUV) outcome. We included 97 children who were dialyzed for at least a 12-month period between January 1985 and December 1999, using either HDF (n = 60; 62%) or PD [n = 37; 38% (86% of those on APD)]. The endpoint was anuria occurrence, defined as a dUV below 50 mL/m2 body surface area (BSA) at three consecutive monthly determinations. Despite the use of HDF as hemodialysis therapy (that is, biocompatible membranes and a very low incidence of vascular instability during ultrafiltration), PD--even predominantly prescribed as APD--was associated with better preservation of residual dUV. At dialysis end, anuria occurred in 65% of the children undergoing HD as compared with 23% of those undergoing PD. The mean age of the children at dialysis start was lower in the PD group. No other significant differences were noted between the groups, either for the rate of uropathies or for the RRF at initiation of dialysis.
Asunto(s)
Riñón/fisiopatología , Diálisis Peritoneal , Orina , Adolescente , Anuria/fisiopatología , Niño , Preescolar , Femenino , Hemodiafiltración , Humanos , Masculino , Diálisis Peritoneal Ambulatoria Continua , Estudios ProspectivosRESUMEN
The posture of the patient influences both the intraperitoneal pressure (IPP) and the peritoneal permeability. We have studied the effects of the supine and the upright position in six children. Two peritoneal equilibration tests (PET) of 90-min dwell time each were performed consecutively, firstly in the supine position and then in the upright position. The same amount of dialysate was instilled (1,000 ml/m2; isotonic 1.36% dextrose) for each PET. Using the same filling volume, the IPP was significantly higher in the upright position (18.4 +/- 4.8 cm H2O) than in the supine position (8 +/- 2.4 cm H2O). The mean percentage IPP increase was 130% +/- 35%. The decline in glucose resorption rate from the dialysate during the PET was significantly lower in the upright position. Despite this greater relative loss of osmotic gradient in the upright than the supine position, no significant difference in net ultrafiltration was noted after 90 min of dwell. The peritoneal equilibration ratio during the PET was lower in the upright than the supine position for urea, creatinine, and phosphate. These results favor performing peritoneal dialysis in a supine position, both to increase dialysis efficiency and to reduce patient discomfort.
Asunto(s)
Peritoneo/metabolismo , Peritoneo/fisiología , Postura/fisiología , Adolescente , Niño , Preescolar , Femenino , Glucosa/farmacocinética , Humanos , Masculino , Cavidad Peritoneal/fisiología , Permeabilidad , Presión , Posición Supina/fisiologíaRESUMEN
An optimal intraperitoneal volume (Vip) may be the most critical and least-used option to enhance higher clearances of small solutes. A higher Vip is more effective in increasing small solute clearances when compated to a lower Vip and more frequent exchanges. Additionally, a higher Vip generates minimal intraperitoneal pressure (Pip) in the supine position. Therefore, the highest tolerated Vip should be used at night while the child is sleeping in the supine position. Therefore, in 5 children, mean age 7 years, 4 months, on continuous cyclic peritoneal dialysis (CCPD) (Baxter HomeChoice), we tested the impact of Vip on tolerance (measured by Pip) measurements, and efficiency [assessed by daily Kt/Vurea and weekly creatinine clearance (Kcreatinine]. Basal Pip was determined for the usually prescribed Vip. Then Vip was increased during a morning outpatient study day, in 30-minute stages, stepping up to an increase of 25% of the basal Pip (upper limit 18 cm of water) level reached at the so-called optimized Vip used for the prescription of an optimal total dialysate volume for a 4-week period. The latest study week was compared to the prestudy week. The optimized Vip of 1230 +/- 70 mL/m2 was significantly higher than the basal Vip, 940 +/- 90 mL/m2. The dialysis dose improved both in terms of Kt/V urea from 0.23 +/- 0.02 to 0.29 +/- 0.03 and Kcreatinine from 60 +/- 5 to 76 +/- 9 L/1.73 m2/week. The supine position allowed the 25% Pip increment from 10.2 +/- 2.5 to 12.5 +/- 3.1 cm water, without any obvious clinical side effects.