The Impact of Increasing the Daytime Dialysis Exchange Frequency on Peritoneal Dialysis Adequacy and Nutritional Status of Chinese Anuric Patients

♦ Objective

To study the effect of increasing the daytime dialysis exchange frequency on dialysis adequacy and nutritional status of Chinese anuric patients.

♦ Setting

University teaching hospital.

♦ Patient

100 anuric patients on continuous ambulatory peritoneal dialysis (CAPD).

♦ Design

50 patients had one additional daytime 2-L exchange (intervention group); the dialysis regimen remained unchanged in the other 50 patients (control group).

♦ Outcome

Dialysis adequacy [Kt/V, weekly creatinine clearance (wCCr), and net ultrafiltration (UF)] and nutritional status [serum albumin, dietary protein intake, represented by normalized protein nitrogen appearance (nPNA), and percent lean body mass (%LBM)] were measured at 0 and 6 months.

♦ Results

Baseline dialysis adequacy and nutritional indices were comparable between the two groups. In the control group, all parameters remained stable at month 6. In the intervention group, there were significant increases in UF, Kt/V, wCCr, nPNA, and %LBM from months 0 to 6. The improvement in nPNA was affected by daily exchange volume. In 30 patients, the number of exchanges was increased from 3 to 4 per day; their Kt/V and nPNA rose significantly from month 0 to month 6. In the other 20 patients, the number of exchanges was increased from 4 to 5 per day; there was a significant increase in Kt/V but nPNA remained static. The change in nPNA correlated inversely with Kt/V at month 0 (Pearson's r = –0.352, p = 0.012). Multivariate analysis with a general linear model showed that age, Kt/V at month 0, and 3 dialysis exchanges per day at month 0 (versus 4 exchanges) were independent predictors of the change in nPNA.

♦ Conclusions

Increasing the number of peritoneal dialysis exchanges effectively increased Kt/V in Chinese anuric CAPD patients. However, the improvement in nPNA correlated inversely with baseline Kt/V. Although increasing the number of exchanges from 3 to 4 per day improved nPNA, increasing the number of daily exchanges beyond 4 may not improve nPNA further.

The Cost Barrier to Peritoneal Dialysis in the Developing World—An Asian Perspective

Countries in Asia vary significantly in culture and socioeconomic status. Dialysis costs and reimbursement structures are significant factors in decisions about the rates and modalities of renal replacement therapy. From our survey of Asian nephrologists conducted in 2001, a number of observations can be made.

In many developing countries, the annual cost of continuous ambulatory peritoneal dialysis (CAPD) is greater than the per-capita gross national income (GNI). The median cost of a 2-L bag of peritoneal dialysis (PD) fluid is around US$5. The absolute cost of PD fluid among countries with significant differences in per-capita GNI actually varies very little. Thus, most renal failure patients can be expected to have problems accessing PD therapy in developing countries in Asia.

In countries with unequal reimbursement policies for PD versus hemodialysis, a lack of incentive to prescribe PD also exists. Automated PD is nearly non existent in many developing countries in Asia.

Some possible ways to reduce the cost barriers to PD in those countries include

• individual governments providing more public funding for treating dialysis patients;

• dialysate-producing companies reducing the cost of their products;

• physicians using appropriately smaller exchange volumes (3 x 2 L) in some Asian patients with smaller body sizes and with residual renal function; and

• reducing the complication rate for PD (for example, peritonitis) thereby reducing the costs required for treatment and hospitalization.