peritoneal dialysis

dialysis /di·al·y·sis/ (di-al´ĭ-sis) [Gr.]

1. the process of separating macromolecules from ions and low molecular weight compounds in solution by the difference in their rates of diffusion through a semipermeable membrane, through which crystalloids pass readily but colloids pass slowly or not at all.

2. hemodialysis.dialyt´ic

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equilibrium dialysis  a technique of determination of the association constant of hapten-antibody reactions.

lymph dialysis  removal of urea and other elements from lymph collected from the thoracic duct, treated outside the body, and later reinfused.

peritoneal dialysis  dialysis through the peritoneum, the dialyzing solution being introduced into and removed from the peritoneal cavity, as either a continuous or an intermittent procedure.

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peritoneal dialysis

n.

The removal of soluble substances and water from the body by transfer across the peritoneum, utilizing a solution which is intermittently introduced into and removed from the peritoneal cavity.

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peritoneal dialysis (PD),

a dialysis procedure performed to correct an imbalance of fluid or of electrolytes in the blood or to remove toxins, drugs, or other wastes normally excreted by the kidney. The peritoneum is used as a diffusible membrane. Peritoneal dialysis may be performed nightly for chronically ill children while they sleep and also may be carried out regularly at home. It is contraindicated in patients with extensive intraabdominal adhesions, localized peritoneal infection, and gangrenous or perforated bowels, although peritonitis may itself sometimes be treated by peritoneal lavage and antibiotics administered during peritoneal dialysis.

method Under local anesthesia a many-eyed catheter is sutured in place in the peritoneum and a sterile dressing is applied. The catheter is connected to the inflow and outflow tubing with a Y connector, and the air in the tubing is displaced by the dialysate to prevent introduction of air into the peritoneal cavity. The amount and the kind of dialysate and the length of time for each exchange cycle vary with the age, size, and condition of the patient. There are three phases in each cycle. During inflow the dialysate is introduced into the peritoneal cavity. During equilibration (swell) the dialysate remains in the peritoneal cavity. By means of osmosis, diffusion, and filtration, the needed electrolytes pass via the vascular peritoneum to the blood vessels of the abdominal cavity, and the waste products pass from the blood vessels through the vascular peritoneum into the dialysate. During the third phase (drain) the dialysate is allowed to drain from the peritoneal cavity by gravity.

interventions The fluid is warmed to body temperature before instillation, and heparin, antibiotics, or other substances may be added to the dialysate. The patient's fluid balance, respirations, pulse, blood pressure, temperature, and mental state are frequently evaluated, and blood glucose and electrolyte levels are tested regularly. The amount of fluid instilled and the amount and character of the fluid drained are noted. Bacteriologic cultures of the drainage are performed regularly. A low-sodium, high-carbohydrate, high-fat 20- to 40-g protein diet is usually offered. Medication for pain may be necessary. Much peritoneal dialysis is now done in the home, not in facility. VNA referral is done for appropriate teaching and assessment with follow-up in dialysis centers. The need for dialysis and the techniques, dangers, and advantages of peritoneal dialysis are explained to the patient and the family.

outcome criteria Peritoneal dialysis may result in several complications, including perforation of the bowel, peritonitis, atelectasis, pneumonia, pulmonary edema, hyperglycemia, hypovolemia, hypervolemia, and adhesions. Peritonitis, the most common problem, is usually caused by failure to use aseptic technique and is characterized by fever, cloudy dialysate, leukocytosis, and abdominal discomfort. Dialysis may usually be continued while the infection is treated with antibiotics, which are given systemically or intraperitoneally. Atelectasis and pneumonia may result from compression of the thoracic cavity, with decreased respiratory excursion and blood flow to the bases of the lungs caused by an excessive volume of dialysate in the peritoneal cavity. Dyspnea, tachypnea, rales, and tachycardia require reevaluating the amount of dialysate, raising the head of the bed, and administering respiratory therapy to prevent atelectasis and pneumonia. Because patients with diabetes are at risk of developing hyperglycemia, serum and urine glucose levels are monitored, and, if necessary, sorbitol may be substituted for glucose in the dialysate. If dialysate fluid is retained in the peritoneal cavity, hypervolemia may occur, predisposing the patient to pulmonary edema and congestive heart failure. If the dialysate is removed too rapidly or if the dialysate used is a hypotonic glucose solution, hypovolemia may result. Adhesions often develop as a result of local irritation to the surrounding tissues caused by the intraperitoneal catheter.

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dialysis

the diffusion of solute molecules through a semipermeable membrane, passing from the side of higher concentration to that of the lower; a method sometimes used in cases of defective renal function to remove from the blood elements that are normally excreted in the urine (hemodialysis). The principles of dialysis are utilized in renal dialysis with a hemodialyzer (hemodialysis) and in peritoneal dialysis.

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extracorporeal dialysis

dialysis by a hemodialyzer. See hemodialysis.

peritoneal dialysis

dialysis through the peritoneum, the dialyzing solution being introduced into and removed from the peritoneal cavity, as either a continuous or an intermittent procedure. See also peritoneal dialysis.

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peritoneal

pertaining to the peritoneum.

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continuous ambulatory peritoneal dialysis

the use of an indwelling catheter with external tubing that is strapped to the body wall when not being used for infusion and drainage of the dialysate fluid.

peritoneal cysts

include vestigial remnants of primordial urogenital organs, cestode intermediate stages, inclusion cysts or lymphatic ectasia.

peritoneal dialysis

the employment of the peritoneum surrounding the abdominal cavity as a dialyzing membrane for the purpose of removing acumulated waste products or toxins. In veterinary medicine, the main indication is acute, reversible renal failure. Certain crystalloids such as urea, creatinine and electrolytes, and some drugs, such as the salicylates, bromides and barbiturates, can be removed.

Fluid equal in osmolarity and similar in chemical composition to normal body fluid is introduced into the peritoneal cavity via a catheter. After a period of time ('dwell time') determined by the molecular weight of the substance being used as the dialyzing solution, the fluid is drained and the cycle repeated.

peritoneal implantation

attachment and growth of other tissues to the peritoneum, e.g. a fetus escaped from the genital tract, direct metastasis of malignant tumors.

peritoneal lavage

see abdominal lavage.

peritoneal lymph

the fluid normally present in very small amount in the peritoneal cavity.

peritoneal membrane

see peritoneum.

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peritoneal dialysis

Nephrology A therapeutic modality used to clear toxic metabolites from Pts with terminal renal failure, using the peritoneum to filter waste products. See Middle molecules.

Peritoneal dialysis types

Intermittent peritoneal dialysis A modality requiring up to 8 hrs/session–only practical for home therapy

Continuous ambulatory peritoneal dialysis A treatment modality in which the Pt exchanges 1.5-3.0 L of sterile dialysate containing hypertonic glucose, 3-5 times/day, requiring 30-40 mins/session, a therapy ideal for diabetics in renal failure who have poor venous access, as insulin may be delivered in dialysate Side effects CAPD results in hyperlipidemia and obesity due to the high glucose of dialysate, and sclerosing peritonitis; long-term failure may be due to peritoneal infections–eg, candidiasis and phaeohypomycosis–Fusarium spp