The status of continuous ambulatory peritoneal dialysis.

CAPD continues to show promise as a continuous internal portable dialysis technique. Although unknown long-term problems may develop, it would seem at this time to offer an acceptable form of chronic dialysis for many patients.

In vitro simulations of peritoneal dialysis. A technique for demonstrating limitations on solute clearances due to stagnant fluid films and poor mixing.

Stagnant fluid films in the peritoneal interstitium and peritoneal cavity may explain low clearances during peritoneal dialysis. Various peritoneal dialysis techniques may influence clearances by enhancing mixing. However, such techniques also may change fresh fluid replacement rates and/or after peritoneal membrane transport characteristics secondary to mechanically, osmotically, or chemically induced changes in the peritoneium and its vasculature.

Continuous ambulatory peritoneal dialysis: three-year experience at one center.

Three years of clinical experience with continuous ambulatory peritoneal dialysis are summarized. Serum urea nitrogen, creatinine, hematocrit, nerve conduction velocity, calcium, inorganic phosphorus, serum proteins, and electrolytes have been maintained in acceptable ranges. Peritonitis, although reduced in incidence because of solutions in plastic bags and a new adapter, is still a problem.

Peritonitis during continuous ambulatory peritoneal dialysis.

We initiated a therapeutic program of continuous ambulatory peritoneal dialysis for patients with chronic renal failure. Our program resulted in many episodes of peritonitis arising from contamination due to the technical aspects of the procedure. Microbiologic evaluation showed that 73% of 97 episodes were culture positive, with gram-positive organisms causing most of the cases, especially early in dialysis.

Follow-up of peritoneal clearances in patients undergoing continuous ambulatory peritoneal dialysis.

Continuous ambulatory peritoneal dialysis (CAPD) might result in peritoneal membrane changes. First, CAPD exposes essentially continuously the peritoneum to peritoneal dialysis solutions. Such solutions differ from the usual extracellular fluid bathing peritoneal tissues.

Comparison of the effects of lactate and acetate on clinical peritoneal clearances.

Peritoneal clearances of urea, creatinine, inulin and dialyzate protein concentration were compared in ten patients using dialysis solutions containing either lactate or acetate. No significant differences were found between solutions containing lactate or acetate.

Peritoneal clearances.

Intermittent peritoneal dialysis may provide borderline adequate dialysis in terms of clearance of small solutes. A number of disease processes could decrease clearances. Drug manipulations and other techniques to increase clearances primarily affect larger solutes.

Clinical studies with a nonvasoactive peritoneal dialysis solution.

Topical application of dialysis solution to the rat microcirculation causes a transient vasoconstriction for 2 to 3 min. We assessed the clinical importance of this vasoconstriction by developing a dialysis solution without vasoactive properties, as assessed in the microcirculatory laboratory. The solution was of similar composition to human extracellular fluid.

Microvascular and clinical effects of altered peritoneal dialysis solutions.

Blood flow in the peritoneum is one of the more important factors governing the efficiency of peritoneal dialysis. Yet there have been no previous studies which relate alterations and control of the peritoneal microcirculation to dialysis efficiency. Thus, we used closed-circuit television microscopy to quantitative the in vivo response (changes in diameter) to dialysis solutions of the small arteries on the mesothelial surface of the rat cecum and arterioles of the rat cremaster muscle.

Equilibration of peritoneal dialysis solutions during long-dwell exchanges.

There is an increasing interest in CAPD for the treatment of chronic uremia. This technique uses long-dwell peritoneal exchanges lasting 4 hr or more. We have determined equilibration curves for multiple solutes during long exchanges with commercially available 1.

Osmotic ultrafiltration with dextran sodium sulfate potential for use in peritoneal dialysis.

Dextran sodium sulfate was evaluated in vitro as a potential non-absorbable osmotic agent for peritoneal dialysis. It was compared to poly(sodium acrylate) which has been shown previously to be effective in rats, but probably toxic. Dextran sodium sulfate induced osmotic ultrafiltration rates as high as 20 ml/min in water but only 2 ml/min in solution containing non-polymer electrolytes presumably because of Gibbs-Donnan effects.

Effects of intraperitoneal nitroprusside on peritoneal clearances in man with variations of dose, frequency of administration and dwell times.

Clinical studies with intraperitoneal nitroprusside were designed to examine drug effects on peritoneal clearances as a function of dose, frequency of administration and dwell times. Increases in clearances and protein losses were seen with 1 mg of nitroprusside per liter of dialysis solution, with progressively greater effects up to maximum doses of 4.5 mg/1.

Peritoneal dialysis: physiology, current applications and future directions.

The peritoneal dialysis system is a sophisticated dialyser. It probably represents a capillary kidney regulating the number of capillaries perfused, the nature of capillaries perfused, and the overall permeability of its membranes. Its sophistication far exceeds that available with extracorporeal man-made haemodialysis systems.

Peritoneal clearances with three types of commerically available peritoneal dialysis solutions. Effects of pH adjustment and intraperitoneal nitroprusside.

Peritoneal clearances were measured in multiple patients with different types of peritoneal dialysis solution to assess the effects of pH, choice of buffer anion (acetate versus lactate), and the effects of nitroprusside (a vasodilator) in combination with different buffer anions and varying pH. The studies show no differences in peritoneal clearances at very low solution pH (less than 6 as is commonly available) as compared to a pH nearer to 7 or above. There were no diffences between solutions with acetate as compared to those with acetate.

Comparison of polymer, glucose, and hydrostatic pressure induced ultrafiltration in a hollow fiber dialyzer: effects on convective solute transport.

Ultrafiltration induced by (1) poly(sodium acrylate), (2) glucose, and (3) hydrostatic pressure was studied in a hollow fiber dialyzer. Poly(sodium acrylate) added to dialysate induced large amounts of ultrafiltration without crossing the dialyzer membrane. Sodium ions of the acrylate polymer were osmotically active but were held in dialysate by the impermeant anionic polymer.