Long-term effect of amino-acid dialysis solution in children on continuous ambulatory peritoneal dialysis

The study involved eight metabolically stable children, with chronic renal failure on continuous ambulatory peritoneal dialysis (CAPD) whom we followed for 12–18 months. For the first 6 months CAPD was performed with dextrose; for the subsequent 6–12 months the morning exchange was substituted with a 1% amino-acid (AA) solution. The following parameters did not change during the study: serum creatinine, uric acid, inorganic phosphate, serum bicarbonate, potassium, cholesterol, triglycerides, total protein, albumin and transferrin. The only parameter that changed was blood urea nitrogen, which increased moderately. The anthropometric parameters did not show significant variation before and after AA dialysis. The plasma AA profile, which under basal conditions showed lower levels of several essential AAs, improved during the treatment period, with a partial correction of the imbalance. It is possible that this correction of plasma AAs may positively influence the metabolism of some organs such as the brain, muscle and those of the hepatosplanchnic region. The intracellular pool of free AAs, measured in polymorphonuclear leucocytes, was severely altered before the treatment and after 6 and 12 months showed only minor variations. It is possible that some modifications in the proportion of the different AAs in the dialysis solution or an improvement in the concentration or in the number of exchanges per day are necessary in order to change the nutritional status and to modify the intracellular AA pool.     

Pharmacokinetics of common antibiotics used in continuous ambulatory peritoneal dialysis

To establish therapeutic guidelines for the use of antibiotics in patients receiving continuous ambulatory peritoneal dialysis (CAPD), we studied the single-dose pharmacokinetics of cefazolin, tobramycin, and vancomycin given intravenously (IV) and intraperitoneally (IP) as well as cephalexin given orally. By the IV or oral route, the antibiotics exhibited half-lives similar to those described in nondialysed, functionally anephric patients. CAPD accounted for only a negligible fraction of the total body clearance when the drugs were given by the IV route. However, when given IP, the drugs were promptly absorbed and achieved therapeutic serum concentrations. The kinetic principle of superposition was applied to predict plasma concentrations after repetitive IP dosing. Therapeutic guidelines are provided.     

Impaired outcome of continuous ambulatory peritoneal dialysis in immunosuppressed patients

BACKGROUND.: Although immunodeficiency predisposes to CAPD peritonitis withfungal or unusual organisms, the role of immunosuppression asa predisposing factor for CAPD peritonitis, as well as the outcomeof such episodes, remains uncertain. METHODS.: The incidence, spectrum of infectious organisms, and outcomeof CAPD peritonitis was retrospectively reviewed in 39 immunosuppressedand 146 non-immunosuppressed patients treated with CAPD overthe calendar year 1993. RESULTS.: Immunosuppressed patients were younger (mean 44 vs 57 years,P<0.001) and had an increased incidence of previous transplantation,glomerulonephritis, systemic lupus erythematosus, and vasculitis.Immunosuppressed patients had more episodes of peritonitis (69/39patients vs 99/147, P<0.001), required more frequent hospitaladmission (25/39 vs 33/146, P<0.001), had more days off CAPD(331 vs 242, P< 0.001), and required more laparotomies toremove infected CAPD catheters (11/39 vs 14/146, P<0.01).Immunosuppression was associated with increased infection dueto S. aureus and fungi, which may have contributed towards increasedmorbidity in this group. Current immunosuppression or a recenthistory of immunosuppression appeared to be equally potent riskfactors for infection. There was a trend for the incidence ofinfection to parallel the aggressiveness of immunosuppression. CONCLUSIONS.: Immunosuppression is an important risk factor for CAPD peritonitis.A high index of suspicion for infection and aggressive chemotherapyare mandatory. CAPD may not be the initial therapy of choicein this high-risk group.     

Factors associated with increased plasma homocysteine in patients using an amino acid peritoneal dialysis fluid.

BACKGROUND: Although amino acid peritoneal dialysate (AAPD) substitution is thought to improve protein-energy malnutrition in patients undergoing peritoneal dialysis (PD), it may also increase plasma homocysteine (Hcy) levels due to the methionine load in the dialysate. However, it is still unclear which factors are important for elevating Hcy in patients treated with AAPD. METHODS: Sixteen malnourished PD patients (age 48+/-18 years) were treated daily with one exchange of 1.1% AAPD for 3 months. The effects of AAPD on nutrition, Hcy, methionine, leptin and insulin resistance were studied. We also analysed factors that influenced plasma Hcy levels. RESULTS: We found a transient increase in serum albumin (P<0.01) after 1 month treatment, especially in patients with serum albumin < or = 3.5 g/dl. Total plasma Hcy increased markedly after AAPD (the peak at month 2, P<0.001) and returned to baseline after ceasing AAPD, despite no changes in dietary methionine intake and serum methionine levels. Eight patients with Hcy increments >5.65 microM (the median) had lesser dietary intakes of protein (P = 0.01) and methionine (P = 0.028), lower body fat mass (P = 0.05) and lower aspartate transaminase (AST) (P = 0.008) before AAPD treatment than patients with lower increments. DeltaHcy was inversely correlated with baseline dietary methionine intake (r = -0.61), protein intake (r = -0.54) and AST (r = -0.51) (all P<0.05). There was no change in leptin or insulin resistance. AAPD treatment significantly increased Kt/Vurea (P<0.001), weekly creatinine clearance (P<0.05) and peritoneal glucose transport (P<0.05). CONCLUSIONS: Treatment with 1.1% AAPD transiently increased serum albumin in malnourished PD patients. However, the methionine load from the dialysate in this study significantly elevated plasma Hcy levels, especially in patients with lower protein and methionine intakes, and lower AST levels. Further long-term studies will be needed to clarify potential nutritional benefits and adverse effects of AAPD.     

Peritoneal-mediastinal leakage complication of peritoneal dialysis

The authors report a case of mediastinal fluid collection resulting from peritoneal-mediastinal communication after continuous ambulatory peritoneal dialysis (CAPD). To the best of the authors’ knowledge, this is the first reported case in the medical literature. A dry cough developed in the patient who had been receiving CAPD for 4 years. A mediastinal mass owing to peritoneal leakage of dialysate to the mediastinum was confirmed by a computed tomography scan taken 4 hours after the intraperitoneal infusion of contrast-mixed dialysate. The leakage persisted for 12 weeks after the discontinuation of CAPD fluid instillation.     

艾考糊精腹透液单袋长时间留腹治疗连续性非卧床腹膜透析患者的安全性和有效性

Objective To evaluate the efficacy and safety of 7.5% icodextrin peritoneal dialysis solution for once-daily long dwell exchange in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Methods A prospective, multicenter, randomized, double blind, parallel controlled study was conducted for 5 weeks in 201 CAPD patients (96 male, 105 female) with mean age (56.1±13.7) years old. These patients were from 7 centers with 98 allocated to the icodextrin group and 103 to the dextrose group randomly. Patients in the icodextrin group were given 7.5% icodextrin and those in the dextrose group were given 2.5% Dianeal?誖PD-2 or PD-4 for the nocturnal long dwell exchange while the diurnal dialysis remained unchanged. During the 4- week treatment, patients were tested every other week for net ultrafiltration, peritoneal creatinine and urea nitrogen clearance after the long dwell. Other laboratory tests and adverse events were recorded. Results Compared to the dextrose group, the net ultrafiltration was up-regulated more significantly from the baseline in the icodextrin group [(342.53±25.79) ml vs (73.59±24.09) ml, P<0.01]. Episodes of net ultrafiltration less than 0 ml in the icodextrin group were much less than those in the dextrose group. Similarly, the mean difference between groups for change from baseline for peritoneal creatinine and urea nitrogen clearance was much higher[（428.02±53.14） ml/12 h vs （－99.79±50.19） ml/12 h， P<0.01； （306.43±53.31） ml/12 h vs (－116.02±51.05） ml/12 h， P<0.01， respectively] in the icodextrin group. In the icodextrin group, there was a decrease in serum sodium and chloride compared with baseline (P<0.01). Serum amylase activity decreased from (87.04±48.01) U/L to (21.59±13.58) U/L(P<0.01). Cholesterol in the icodextrin group was lower than baseline (P<0.05). There was no significant difference between two groups for the incidence and severity of adverse events. Conclusion 7.5% icodextrin is a safe and effective peritoneal dialysis solution for once-daily long dwell exchange in CAPD patients.     

Long-term use of 1.1% amino acid dialysis solution in hypoalbuminemic continuous ambulatory peritoneal dialysis patients

INTRODUCTION: Malnutrition is a common problem in patients treated with continuous ambulatory peritoneal dialysis (CAPD). Hypoalbuminemia in CAPD patients is an independent risk factor for death and is associated with malnutrition. Previous short-term studies have examined the use of amino acid based PD solutions in terms of albumin levels and anthropometric changes, but not clinical outcome. We report on the extended use of 1.1% amino acid based peritoneal dialysis solution (Nutrineal) and have assessed clinical utility in terms of nutrition, biochemical indices, dialysis adequacy and clinical outcomes. METHODS: The effect of Nutrineal was studied retrospectively in 22 patients during the past 30 months. All patients had an albumin level of < 35 g/l prior to commencing Nutrineal, and had either a protein intake < 1.2 g/kg or weight loss of > 5% in the previous 3 months. 19 of the 22 patients underwent an 8-week trial of oral nutritional supplements with no improvement in serum albumin level. Albumin level, normalized protein catabolic rate, weight, Kt/V and creatinine clearance were assessed for all patients prior to Nutrineal and at the end of the study period. RESULTS: The mean time on Nutrineal therapy was 13.6 months (range 6-26 months). There were no reported side effects of the treatment. There was an average of 1 episode of peritonitis per 23 treatment months, and only 1 patient died (4% annually adjusted mortality cf 8.9% on the peritoneal dialysis program as a whole). There was a significant increase in albumin level from 22.45 +/- 0.97 range 14-33 g/l to 25.68 +/- 1.159 range 16-35 g/l (p = 0.0036). Normalized protein catabolic rate increased significantly, from 0.898 +/- 0.053 to 1.085 +/- 0.056 g/kg/day (p = 0.0057). Weight decreased slightly although this did not reach statistical significance. Kt/V and creatinine clearance both decreased significantly, but remained within the adequate range in > 80% of the patients. There was no significant change in residual renal function (mean residual creatinine clearance 3.8 +/- 0.59 ml/min at the start of the study period, cf 3.4 +/- 0.61 ml/min at the end). CONCLUSION: These data suggest that Nutrineal can be used safely and effectively for an extended period of time. Such use is associated with a low mortality rate and a low peritonitis rate, although dialysis adequacy is compromised to a degree.     

High prevalence of ascorbate deficiency in an Australian peritoneal dialysis population

BACKGROUND: An adequate total body pool of ascorbate is essential for optimum health in humans. Requirements for ascorbate are increased in peritoneal dialysis (PD) patients most likely due to a combination of poor nutrition and increased dialysate losses. METHODS: We measured serum ascorbate levels in 45 clinically stable PD patients to assess the prevalence of ascorbate insufficiency (level between 2 and 4 mg/L) and deficiency (level <2 mg/L). We also assessed the efficacy of subsequent supplementation and patients' adherence to the prescribed supplementation. All patients were advised on commencement of dialysis to take a multivitamin tablet containing 100-120 mg ascorbate. RESULTS: Eighteen (41%) PD patients were regularly taking ascorbate-containing multivitamins, while 27 (59%) patients did not take ascorbate supplements. Serum ascorbate levels ranged from <0.2 to 41 mg/L, with wide variations in serum ascorbate at any given intake level. Ascorbate deficiency was present in 1/3 of the current PD population (44% of patients not taking supplements and in 16% of those on supplements), although none of the patients demonstrated clinical manifestations of scurvy. Targeted supplementation of ascorbate insufficient patients increased the median serum ascorbate level from 1.7 mg/L (IQR 1.2-2.2) to 22.5 mg/L (IQR 16.7-32.9). CONCLUSION: Our results show that, in PD patients, ascorbate deficiency is common and can readily be identified with serum ascorbate measurements. Oral supplements in the form of inexpensive multivitamin preparations restore adequate serum ascorbate levels in the majority of these patients. We therefore suggest measurement of ascorbate levels in all PD patients at the commencement of dialysis with a target level in the normal range (4-14 mg/L).     

Biocompatibility of a bicarbonate-buffered amino-acid-based solution for peritoneal dialysis

Amino-acid-based peritoneal dialysis (PD) fluids have been developed to improve the nutritional status of PD patients. As they may potentially exacerbate acidosis, an amino-acid-containing solution buffered with bicarbonate (Aminobic) has been proposed to effectively maintain acid-base balance. The aim of this study was to evaluate the mesothelial biocompatibility profile of this solution in comparison with a conventional low-glucose-based fluid. Omentum-derived human peritoneal mesothelial cells (HPMC) were preexposed to test PD solutions for up to 120 min, then allowed to recover in control medium for 24 h, and assessed for heat-shock response, viability, and basal and stimulated cytokine [interleukin (IL)-6] and prostaglandin (PGE(2)) release. Acute exposure of HPMC to conventional low-glucose-based PD solution resulted in a time-dependent increase in heat-shock protein (HSP-72) expression, impaired viability, and reduced ability to release IL-6 in response to stimulation. In contrast, in cells treated with Aminobic, the expression of HSP-72 was significantly lower, and viability and cytokine-producing capacity were preserved and did not differ from those seen in control cells. In addition, exposure to Aminobic increased basal release of IL-6 and PGE(2). These data point to a favorable biocompatibility profile of the amino-acid-based bicarbonate-buffered PD solution toward HPMC.     

腹膜透析剂量与残余肾功能及透析质量的关系研究

目的观察慢性肾脏病5期患者应用非透析治疗、不同腹膜透析剂量治疗对肾功能的影响。方法选取慢性肾脏病5期的非糖尿病肾病患者,采用非透析保守治疗者20例,腹膜透析剂量4升／天者26例、6升／天者35例及8升／天者43例。随访观察1年,检查各项指标及肾功能的变化。结果随访1年后,非透析患者血压的控制较4升／天腹膜透析组差（P〈0．05）,血清白蛋白水平、血钙水平低于4升／天透析组,血磷及甲状旁腺素水平高于不同剂量透析组。各组尿量及残余肾功能均有不同程度的下降,其中腹膜透析各组尿量、肾功能及非透析组肾功能均较观察前具有统计学差异（P〈0．05）,而各组之间肾功能下降的幅度未见显著性差异（P〉0．05）。结论慢性肾脏病5期患者早期的腹膜透析治疗对患者钙磷代谢、蛋白质营养改善及血压的控制优于非透析治疗。腹膜透析治疗对残余肾功能的保护与非透析治疗相比未见明显优势,不同的透析剂量在1年的观察期内未显示对肾功能的影响。     

Hemodialysis using a low bicarbonate dialysis bath: Implications for acid-base homeostasis

The low bath bicarbonate concentration ([]) used by a nephrology group in Japan (25.5 mEq/L), coupled with a bath [acetate] of 8 mEq/L, provided an opportunity to study the acid-base events occurring during hemodialysis when flux is from the patient to the bath. We used an analytic tool that allows calculation of delivery during hemodialysis and the physiological response to it in 17 Japanese outpatients with an average pre-dialysis blood [] of 25 mEq/L. Our analysis demonstrates that addition is markedly reduced and that all of it comes from acetate metabolism. The added to the extracellular fluid during treatment (19.5 mEq) was completely consumed by H+ mobilization from body buffers. In contrast to patients dialyzing with higher bath [] values in the US and Europe, organic acid production was suppressed rather than stimulated. Dietary analysis indicates that these patients are in acid balance due to the alkaline nature of their diet. In a larger group of patients using the same bath solution, pre-dialysis blood [] was lower, 22.2 mEq/L, but still in an acceptable range. Our studies indicate that a low bath [] is well tolerated and can prevent stimulation of organic acid production.     

Quality of life of caregivers and patients on peritoneal dialysis.

Peritoneal dialysis is the archetypal home-based therapy and is often favoured by patients. However, as patients with end-stage renal failure become more elderly, with more co-morbidity, their dependence on carers to provide physical, emotional and logistical support increases. The effect of this chronic burden has not been systematically studied. We have prospectively studied patients with end-stage renal failure starting peritoneal dialysis and their carers over a 1-year period. We selected a cohort of caregivers that are actively involved with the care of their partners' dialysis. Quality of Life (QoL) assessed by SF-36 questionnaires showed the patients and carers had impairment of QoL at the start of dialysis. As expected, the baseline QoL Physical Component Scores highly correlated with co-morbidity and assessment of functional capacity. Scores of all QoL domains improved after 1 year and this reached statistical significance for social functioning for both patients and carers. When we compared carers of highly dependent patients (required to perform daily dialysis) with carers of less dependent patients, we noted that the former had a statistically significant worsening of their mental health but other parameters were not different. We have shown that despite increasing the burden for caregivers, with careful selection, education and support, we did not adversely impact on the QoL of carers whilst there was some evidence of improvement, especially in social functioning. This gives reassurance that establishing dependent patients on PD is compatible with a holistic approach to the patients and their families.     

Culture-negative peritoneal dialysis peritonitis associated with pancreaticoduodenocystotomy leak of a pancreas transplant

Background:Peritoneal dialysis (PD) peritonitis is usually caused by infection and less commonly by a sterile inflammatory reaction.Methods:The authors report the case of a kidney-pancreas transplant recipient who was receiving PD after kidney transplant rejection 5 years after transplantation. The patient had a viable pancreas transplant. He had abdominal pain associated with cloudy PD effluent. The PD leukocyte count was elevated with a predominance of monocytic leukocytes.Results:Blood, urine, and PD effluent cultures were negative. An ultrasound scan of the transplanted kidney and a computerized tomography (CT) scan of the abdomen and pelvis did not identify the cause of the peritonitis. Foley catheter decompression of the bladder resulted in improvement of the abdominal pain and PD effluent leukocytosis. Twenty-five days later, the patient again experienced abdominal pain and cloudy PD effluent. Cultures of blood and PD effluent were again negative. CT scanning and cystoscopy of the transplanted pancreas identified a leak at the pancreaticoduodenocystotomy anastamosis. Urinary bladder decompression was followed by surgical exploration that identified an erosion of the distal transplanted duodenum, necessitating enteric diversion of the transplanted pancreas's exocrine secretions. The patient underwent conversion to hemodialysis, and the pancreas transplant continued to function well. He has subsequently received a living related kidney transplant.Conclusion:This is the first reported case of noninfectious PD peritonitis caused by pancreaticoduodenocystotomy leak in a patient with a functional pancreas transplant.     

Prevalence and risk factors for hepatitis C virus infection in continuous ambulatory peritoneal dialysis patients

BACKGROUND.: Studies on hepatitis C virus antibodies (Anti-HCV) in CAPD patientsare scarce and include a small number of patients. Nevertheless,risk factors related to Anti-HCV in these patients are stillsubject to controversy. PURPOSE OF THE STUDY.: To analyse the incidence and risk factors associated with thepresence of Anti-HCV in CAPD patients. METHODS.: We studied 255 patients from five different treatment centresof our region. The analysis was repeated after excluding 161patients who had previously received haemodialysis treatmentat least once. Anti-HCV testing was made by the 2nd-generationELISA. As a supplementary test we used RIBA-4 in three centersand INNOLIA in the other two. Risk factors were analysed usinglogistic regression model for multivariate analysis. RESULTS.: In the whole group, 29 patients (11.4%) were anti-HCV positive.Logistic regression analysis determined the following variablesas independent risk factors: hepatitis previous to CAPD (P<0.0001,odds ratio (OR): 44.9), Anti HBc positivity (P=;0.019, OR: 9.24),blood transfusions previous to CAPD (P=;0.015, OR: 1.05) andCAPD duration (P=0.025, OR: 1.02). When patients who had previouslyundergone haemodialysis were excluded, the prevalence of HCVantibodies was 8.5% (8/94). In this group multivariate analysisshowed that Anti-HCV positivity correlated with hepatitis previousto CAPD (P<0.0003, OR: 126) and Anti HBc positivity (P=0.002,OR: 41.9). CONCLUSIONS.: Our prevalence of hepatitis C virus (HCV) infection in CAPDpatients was lower than other renal replacement therapy modalities,and correlated to events occurring mainly before starting CAPDtreatment. This technique could be considered as low risk forHCV infection.     

Video-assisted thoracoscopic talc pleurodesis is effective for maintenance of peritoneal dialysis in acute hydrothorax complicating peritoneal dialysis.

BACKGROUND: Acute, massive, unilateral hydrothorax is an uncommon but well-recognized complication of peritoneal dialysis. Its clinical course and treatment outcome after a recently advocated technique of video-assisted thoracoscopic (VATS) talc pleurodesis remains unclear. METHODS AND RESULTS: Between July 1998 and March 2002, among 475 CAPD patients in two regional hospitals in Hong Kong, nine patients (three men, six women, mean age 53+/-12 years) developed acute hydrothorax due to pleuroperitoneal communication (R=8, L=1) within 5.8+/-4.2 months (median, 5.2 m; range, 2 days to 11.6 months) of commencing peritoneal dialysis. Analysis of simultaneously obtained peritoneal and pleural fluid in all subjects only showed concordance in protein content (consistently<4 g/l), while fluid glucose and lactate dehydrogenase levels were not comparable. The methylene blue test was negative (n=4). Radionuclide scan (n=6) and contrast CT peritoneography (CTP, n=3) detected pleuroperitoneal communication in half and one-third of the patients, respectively. All patients underwent pleurodesis achieved by talc insufflation into the pleural cavity under VATS guidance. All patients were successfully returned to peritoneal dialysis. After a mean follow-up of 18.8+/-12.5 months, hydrothorax recurred in one patient (at 7 months after pleurodesis), who was successfully treated by repeating the procedure. CONCLUSIONS: Hydrothorax complicating CAPD is more commonly right-sided, and tends to occur within the first year of starting peritoneal dialysis. Isotope scan and CTP are insensitive in diagnosing pleuroperitoneal communication. A low pleural fluid protein content is the most consistent biochemical finding. VATS talc pleurodesis is a safe and reliable treatment of choice that allows sustained continuation of CAPD with low recurrence rate.     

Predictive value of dialysis adequacy and nutritional indices for mortality and morbidity in CAPD and HD patients. A longitudinal study

BACKGROUND: The effects of dialysis inadequacy on patient survival and nutritionalstatus and that of malnutrition on survival have not been clearlyassessed. Studies comparing dose/mortality and morbidity curveson continuous ambulatory peritoneal dialysis (CAPD) and on haemodialysis(HD) are also needed, to assess adequate treatment on CAPD. METHODS: We have evaluated the effects of age, 13 pretreatment risk factors,serum albumin, transferrin, normalized protein catabolic rate,Kt/V, normalized weekly creatinine clearance, residual renalfunction and subjective global assessment of nutritional statuson survival and morbidity, in a 3-year prospective study of68 CAPD and 34 HD patients. RESULTS: Survivals did not differ for CAPD and HD patients. In the Coxhazard regression model, age, peripheral vasculopathy, serumalbumin <3.5 g/dl and Kt/V < 1.0/treatment on HD and <1.7/weekon CAPD were independent factors negatively affecting survival.On the contrary, adjusted survivals were not affected by gender,modality, other comorbid factors, normalized protein catabolicrate, or subjective global assessment of nutritional status.Persistence of residual renal function significantly improvedsurvival. Observed and adjusted survival did not significantlydiffer for CAPD and HD patients with either low (HD, <1.0/treatment;CAPD, < 1.7/week) or high ( 1.0 and 1.7) Kt/V. On HD, adjustedsurvivals were similar for 1.0 Kt/V < 1.2 or 1.2. On CAPD,Kt/V 1.96/week was associated with definitely better survival,with only one death/23 patients versus 19/45, with Kt/V 1.96.Survival was not different for 1.96 Kt/V < 2.03 and 2.03.Normalized weekly creatinine clearance and wKt/V were positivelyrelated on CAPD (r 0.39, P<0.01) and wKt/V=1.96 correspondedto 58 litres of normalized weekly creatinine clearance. CONCLUSION: Indices of adequacy were predictors of mortality and morbidity,both on CAPD and HD, whereas normalized protein catabolic rateand subjective global assessment of nutritional status werenot. Serum albumin did not decrease during dialysis; hence itspredictive effect for survival is due to the predialysis conditionand not to dialysis-induced malnutrition.