Ysis Prescription and Peritoneal Membrane Transport Characteristics on Nutritional Status

These data suggest that dialysis dose is one of the major determinants of protein and energy intake in PD patients and that higher doses of dialysis tend to improve outcome. The data also suggest that with a long time on PD the peritoneal membrane probably has some underlying histological changes that preclude it from optimally responding to injury and may predispose it to irreversible damage. A possible early finding in this case is an increase in peritoneal transport in patients whose transport was initially stable. Peritoneal membrane transport properties are an important determinant of not only dialysis dose, but also nutritional status via both direct and indirect means. It is therefore important to identify the individual patient's peritoneal membrane transport characteristics. These transport characteristics may change over time. High transporters on CAPD represent a unique challenge. They have ultrafiltration problems and a tendency toward protein malnutrition presumably due to increased dialysate protein losses while on CAPD. One must consider that malnutrition in a rapid transporter may be due to the fact that the patient is on the wrong PD therapy. A change to NIPD may rectify some of the biochemical parameters, but these patients may not always improve. Reasons for this occasional lack of improvement are multifactorial, but emphasize our need to look at each patient as an individual and not focus only on laboratory parameters.

Albumin and Amino Acid Levels as Markers of Adequacy in Continuous Ambulatory Peritoneal Dialysis

Similar to previous findings in HD patients, a markedly decreased serum albumin level has been found to be a strong predictor of morbidity and mortality in CAPD patients. However, a slight decrease in serum albumin levels (to about 30 g/L if measured with nephelometry or the bromcresol purple method) does not always seem to reflect impaired nutritional status or to be associated with an increased morbidity or mortality in CAPD patients. A low serum albumin level among CAPD patients is related to dialysate albumin loss, comorbidity, age, and a low dietary protein intake. The possible relation between the dialysis dose (as assessed by small solute clearances) and serum albumin levels among CAPD patients is much less established and needs further study, although serum albumin tends to increase in prospective studies of increased peritoneal dialysis dose.

Although the plasma levels of amino acids seem to be lower in CAPD patients compared to HD patients, this does not reflect the intracellular amino acid pattern in muscle which is less abnormal in CAPD patients, possibly because of the sustained hyperinsulinemia during CAPD, resulting in an in creased intracellular to extracellular gradient. It is at present not established to what extent the amino acid abnormalities are related to the dialysis dose.

Malnourished and hypoalbuminemic CAPD patients should be recommended to increase the protein intake, and if this is not effective, the dialysis dose should be increased. Furthermore, the use of amino acid-based peritoneal dialysis solutions is a promising new tool for the treatment of malnourished CAPD patients and may become an important component of CAPD therapy in the future. On the other hand, if the nutritional status deteriorates in spite of these efforts, the patient should be transferred to hemodialysis if possible.

Capd Viability: A Long-Term Comparison with Hemodialysis

Objective

To compare the long-term viability of continuous ambulatory peritoneal dialysis (CAPD) to that of hemodialysis (HD).

Design

Retrospective study of patients of our institution starting dialysis between January 1,1981, and December 31, 1993, and surviving for at least 2 months.

Patients

Five hundred and seventy-eight new patients (51.3% on CAPD and 48.6% on HD).

Main Outcomes Studied

Cox -adjusted assessment of patient and technique survival, and of technique success. Differences in results for two successive periods of time.

Results

Patient survival did not differ between CAPD and HD after adjusting for age and comorbidity, and significantly improved in the second part of the follow-up (1987 -1993). Technique failure was significantly higher on CAPD, in which it was inversely related to age. The probability of a patient continuing on the first method of dialysis (“technique success”) was significantly lower on CAPD than on HD, but the difference decreased progressively with age and disappeared in patients ≥75 years.

Conclusion

CAPD is as effective as HD in preserving life in uremic patients in the long-term, and gives better results in the older elderly. In adults, the lower technique success rate may not be a problem for patients with access to a good transplantation program; for others, this drawback must be weighed against the advantages of home treatment.

The importance of monitoring dialysis adequacy in chronic peritoneal dialysis

The case of a patient who was noted to be malnourished but improved after his dialysis dose was increased is presented. This case and the discussion that follows emphasize the importance of proactively monitoring peritoneal dialysis adequacy and nutritional intake, supporting the notion that the dose of peritoneal dialysis is a major determinant of appetite and, consequently, of nutritional status. In the clinical setting, this influence is best indicated by changes in the serum albumin level and ultimately in long-term patient survival. The case discussion reviews the major principles and supporting literature, describing how we target peritoneal dialysis delivery and optimize nutritional status in an effort to reduce morbidity and mortality.