Clinical impact of a combined therapy of peritoneal dialysis and hemodialysis.

AIMS: Although peritoneal dialysis (PD) is recommended as the first-line treatment for end-stage renal disease, limitations exist to achieving good clinical status when the residual renal function (RRF) has declined. Combined therapy with PD and hemodialysis (HD) is the treatment of choice for patients who cannot control body fluid status and/or cannot obtain adequate solute removal by PD alone. The aim of this study was to evaluate the clinical efficacy of this combined therapy. METHODS: In this retrospective study, 53 patients on PD and diagnosed with underdialysis and/or overhydration with declining RRF were recruited. Parameters of volume control, uremic solute removal, anemia, and predictors for encapsulating peritoneal sclerosis (EPS) were compared before and 1 year after combined therapy. RESULTS: The patients' hydration status improved significantly with reductions in atrial natriuretic peptide and blood pressure. Serum creatinine and beta2 microglobulin also decreased significantly. The hemoglobin level increased remarkably from 8.2 ± 1.6 to 10.7 ± 1.2 g/dl (p < 0.01) and the reticulocyte count also increased significantly, even though at the same time the dose of recombinant human erythropoietin decreased significantly. The dialysate to plasma creatinine ratio obtained from the fast peritoneal equilibration test (PET) decreased significantly from 0.65 ± 0.11 to 0.59 ± 0.13, and the level of interleukin 6 in PET drainage also significantly decreased. Furthermore, serum C-reactive protein and fibrinogen decreased significantly. CONCLUSIONS: Combined therapy with PD and HD is an effective way to control fluid status and to correct inadequate solute removal, leading to improvement in inflammation, peritoneal function and anemia.

Renal ultrasonography is useful for evaluating diabetic renal failure.

AIM: It has been reported that the course of renal function is heterogeneous in patients with diabetic nephropathy. This study was undertaken to examine the clinical usefulness of renal ultrasonography in evaluating diabetic chronic renal failure (CRF) patients. METHODS: The renal sizes of type 2 diabetic patients with various degrees of renal injury, non-diabetic subjects without renal diseases and patients with non-diabetic CRF were measured by ultrasonography. The renal area index (RAI) was calculated from renal measurements and body surface area. The rate of renal function decline (delta l/cre) was analyzed by calculating the slope of the regression line for the reciprocal of serum creatinine concentrations over time. The correlations between delta l/cre and various clinical and laboratory parameters, including RAI, were analyzed. RESULTS: The RAI values of type 2 diabetic patients with nephropathy increased on the whole. It was also found that the RAI value of diabetic CRF patients was heterogeneous. There was a significant correlation between RAI and log delta l/cre (r = 0.492, p < 0.01). In addition to RAI, urinary protein excretion, serum albumin concentration and mean blood pressure significantly correlated with log delta l/cre. The correlation between RAI and log delta l/cre remained significant after adjustment for age, gender and serum albumin concentration. However, it was no longer significant after inclusion of mean blood pressure in the multivariate analysis. CONCLUSION: Although RAI is not a completely independent predictor of the risk of progression of diabetic renal failure, RAI could be a useful marker for the evaluation of diabetic renal failure. Renal involvement in diabetic patients is heterogeneous, and since renal ultrasonography is non-invasive and safe to perform, it is useful in evaluating diabetic CRF patients.

[Significance of residual renal functions of patients with end-stage renal failure undergoing continuous ambulatory peritoneal dialysis].

It is generally accepted that residual renal function remains well-preserved longer with CAPD than with hemodialysis. However, consideration and impact of the contributory effects of residual renal function on the adequacy of renal replacement therapy has not been well defined. In this report, creatinine clearance (Ccr), Kt/V, normalized protein catabolic rate (nPCR) and urinary excretion of uremic solutes were studied in 26 stable CAPD patients with a four-bag exchange. Weekly Ccr, weekly Kt/V and nPCR were 62.3 +/- 20.2 l/week/1.73 m2, 1.77 +/- 0.35, and 0.90 +/- 0.13 g/kg/day, respectively. These parameters correlated significantly with the daily urine volume. The weekly Ccr and Kt/V of anuric patients seemed to be inadequate. Urinary excretion of urea nitrogen, Cr, Na, Cl, Pi and beta 2-microglobulin (beta 2-MG) were dependent upon the daily urine volume. Significant phosphorus and beta 2-MG excretion seemed to have an effect on the prevention of bone and joint complications, because serum iPTH and beta 2-MG levels increased after the patients fell into an anuric state. It was suggested from this study that CAPD should be started before the patient loses residual renal function because four bag exchange as the standard CAPD prescription might not be adequate once the patient loses urine excretion.

[The impact of low calcium dialysate (1.25 mmol/l; LCD) on bone metabolism in CAPD patients].

The aim of this study was to evaluate the influence of LCD on bone metabolism, and assess the indication of LCD. Fourteen patients on CAPD (m = 8, f = 6) were converted to LCD following over 1 year on standard calcium dialysate (1.75 mmol/l; SCD) treatment, and followed for 1 year. The biochemical measurements included plasma levels of Ca, P, ALP, and i-PTH. The bone mineral density (BMD) was evaluated using dual energy x-ray absorptiometry. Ca-carbonate and calcitriol were administered to maintain plasma Ca levels within the normal range. The patients were divided into three groups on the basis of the i-PTH levels just before the conversion to LCD. Group 1; n = 5, i-PTH < 65. Group 2; n = 5, 65 < or = i-PTH < 200. Group 3; n = 4, 200 < or = i-PTH (pg/ml). Mean BMD Z scores decreased significantly in group 3. Mean serum i-PTH significantly increased in all groups. These results suggest that LCD is effective for treating adynamic bone disease, which is seen in high frequency in patients undergoing peritoneal dialysis. However, these results also pointed to the disadvantage of worsening the secondary hyperparathyroidism. In conclusion, LCD should be used carefully in patients whose i-PTH levels are high, because of the possibility of bone mineral loss.

[Factors influencing residual renal function of CAPD patients].

It is generally accepted that residual renal function has significant meaning in dialysis adequacy of CAPD patients. However, the factors influencing the residual renal function have not been investigated yet. We evaluated the consequences of following factors on residual urine volume in 50 CAPD patients: deterioration rate of renal function (slope of I/serum creatinine) before dialysis, renal creatinine clearance at the initial point of dialysis and the episodes of rapid reduction of residual urine volume. There was no correlation between the deterioration rate of renal function before dialysis and the residual urine volume. On the contrary, there was significant correlation between renal creatinine clearance at the initial point of dialysis and the residual urine volume in the first 4 years on CAPD. We recognized 67 episodes of rapid reduction of residual urine volume after initiation of CAPD. Inappropriate management or complications attributed to the rapid urine volume reduction in 50 episodes. The residual urine volume did not recover to the previous level in 40 episodes. We concluded that early initiation of CAPD and evasion of decreasing residual urine volume caused by inappropriate management or complications have important meaning and will preserve residual renal function of CAPD patients.

[Clinical evaluation of cases with massive ascites accumulation after discontinuation of CAPD: an attempt to establish the concept of the pre-sclerosing encapsulating peritonitis(pre-SEP) state].

Sclerosing encapsulating peritonitis(SEP) is a most serious complication of continuous ambulatory peritoneal dialysis(CAPD). Although the criteria of diagnosis and guidelines for therapy of SEP have been proposed by the Japanese SEP Study Group already, SEP is refractory to treatment when the disease process is complete. It is important to detect the latent phase of SEP(pre-SEP state) in order to treat patients at an early stage. We evaluated the characteristics of ascites in four patients with massive ascites accumulation after discontinuation of CAPD. Age and the duration of CAPD of the subjects were 53.3 +/- 9.7 years and 126.5 +/- 6.8 months, respectively. However, the patients were withdrawn from CAPD because of peritonitis or ultrafiltration failure. We also followed cytokines and parameters of collagen metabolism of ascites in two patients during adrenocorticosteroid therapy and conducted a histopathological evaluation of the peritoneum of an autopsy case who had died of pneumonia. Ascites seems to be exudative because of the high concentration of protein, cytokines and parameters of collagen metabolism such as interleukin-1 beta, interleukin-6, transforming growth factor-beta 1, procollagen 3 peptide, and type IV collagen 7S, the levels of which were 21.3 +/- 9.3 pg/ml, 8,153 +/- 7,327 pg/ml, 6.7 +/- 3.6 ng/ml, 89.3 +/- 67.8 U/ml, and 59.0 +/- 36.2 ng/ml, respectively. The histopathological findings of the peritoneum from the autopsy case showed dense fibrous tissue permeated with inflammatory infiltration and widespread infiltration of fibrin. These findings suggested that the peritoneum was inflamed when massive ascites accumulated. The amount of ascites and concentration of cytokines and parameters of collagen metabolism of ascites diminished during adrenocorticosteroid therapy. We concluded that massive and refractory accumulation of ascites appearing after the discontinuation of CAPD should be regarded as a sign of the pre-SEP state, and prophylactic treatment should be started at this stage of disease.

[A study on the mechanism of enhanced diuresis following direct hemoperfusion with polymyxin B-immobilized fiber].

In the present study, we applied direct hemoperfusion with polymyxin B-immobilized fiber(PMX-DHP) to patients who developed endotoxin shock after laparotomy, and examined the influence of PMX-DHP on the kidney function. Seven patients were enrolled in this study, whose conditions were matched to the following criteria: 1) endotoxin shock was highly suspected, 2) blood pressure became stable before PMX-DHP was indicated, 3) renal function(demonstrated with creatinine clearance(CCr) and fractional excretion of sodium (FENa)) was proven before the surgery. All patients underwent emergency surgery in Fuji City General Hospital because of perforative peritonitis. A 2-hour session of PMX-DHP was performed on the day of the laparotomy and the second 2-hour treatment was performed the following day. Urine was collected at 2 hours before starting PMX, during the treatment, and 2 hours after PMX-DHP, and urine volume(U-Vol), sodium and creatinine levels of urine were monitored. Sodium and creatinine levels in the serum were measured at the start and end of the PMX-DHP session. Average atrial natriuretic polypeptide (ANP) was obtained using a total of 8 samples from the 14 treatment sessions. Parameters of hemodynamics such as pulmonary capillary wedge pressure(PCWP) were monitored at the start and end of PMX-DHP session. Urine volume increased significantly during and after PMX-DHP. The change in urine volume correlated significantly with the change in CCr during PMX-DHP, and with the change in FENa after PMX-DHP. The change in FENa was significantly correlated with the changes in hemodynamic factors such as PCWP and with the change in serum ANP, but no significant correlation was observed between the change of CCr and the other parameters. In conclusion, the early increase in urine volume with PMX-DHP treatment might be attributable to the increase in glomerular filtration independently of systemic hemodynamic factors.