Wai Kei Lo

A 3-year, prospective, randomized, controlled study on amino acid dialysate in patients on CAPD

BACKGROUND Malnutrition is prevalent in patients on continuous ambulatory peritoneal dialysis (CAPD) and confers a poor prognosis. Inadequate nutrient intake is an important contributing factor. Although short-term studies have shown mild to modest nutritional benefit with amino acid dialysate, its long-term effects and tolerability remain obscure. METHODS The authors have performed a 3-year, randomized, prospective, controlled study of amino acid dialysate in malnourished Chinese patients on CAPD. Sixty patients were assigned randomly to either replace 1 exchange daily with amino acid dialysate (Nutrineal; DAA group, n = 30) or to continue with dextrose dialysate (Dianeal; DD group, n = 30). RESULTS The 2 groups had similar mortality, hospitalization duration, serial C-reactive protein levels, and drop-out rates during the study. Biochemical nutritional parameters including albumin and cholesterol decreased in the DD group but remained stable or increased in the DAA group. The composite nutritional index did not differ between the 2 groups throughout the study period. Triglyceride decreased only in DAA-treated patients. Normalized protein equivalent of nitrogen appearance and dietary protein intake showed a sustained increase only in DAA patients. The nutritional benefit of DAA appeared more prominent in women, whose lean body mass and body mass index was maintained with DAA but not with DD. Mass transfer area coefficient for creatinine increased in DAA-treated patients, whereas that for urea as well as macromolecular restriction coefficients remained stable. Total Kt/V(urea) and daily ultrafiltration volume were similarly maintained in the 2 groups throughout the study. CONCLUSION Long-term administration of amino acid dialysate is well tolerated and presents a means to improve the nutritional status in high-risk patients. The current study, however, has not shown a significant effect of amino acid dialysate on patient survival.

A Combination of Biocompatible Peritoneal Dialysis Solutions and Residual Renal Function, Peritoneal Transport, and Inflammation Markers: A Randomized Clinical Trial

BACKGROUND The benefits of biocompatible peritoneal dialysis (PD) fluids, particularly for residual renal function (RRF), are controversial. Moreover, the clinical effects of a PD regimen consisting of different biocompatible PD fluids have not been fully established. STUDY DESIGN Prospective, randomized, controlled, open-label study. SETTING & PARTICIPANTS Patients with end-stage kidney disease newly started on continuous ambulatory PD therapy (N = 150). INTERVENTION A 12-month intervention with 3 biocompatible PD fluids (a neutral-pH, low glucose degradation product, 1.5% glucose solution; a solution with 1.1% amino acid; and a fluid with 7.5% icodextrin) or conventional PD fluid. OUTCOMES The primary outcome was change in RRF and daily urine volume. Secondary outcomes were peritoneal transport and inflammation markers. MEASUREMENTS RRF, daily urine volume, serum and dialysate cytokine levels. RESULTS RRF(3.24 ± 1.98 vs 2.88 ± 2.43 mL/min/1.73 m(2); P = 0.9) and rate of decline in RRF (-0.76 ± 1.77 vs -0.91 ± 1.92 mL/min/1.73 m(2) per year; P = 0.6) did not differ between the biocompatible- and conventional-PD-fluid groups. However, patients using the biocompatible PD fluids had better preservation of daily urine volume (959 ± 515 vs 798 ± 615 mL/d in the conventional group, P = 0.02 by comparison of difference in overall change by repeated-measures analysis of variance). Their dialysate-plasma creatinine ratio at 4 hours was higher at 12 months (0.78 ± 0.13 vs 0.68 ± 0.12; P = 0.01 for comparison of the difference in overall change by repeated-measures analysis of variance). They also had significantly higher serum levels of adiponectin and overnight spent dialysate levels of cancer antigen 125, adiponectin, and interleukin 6 (IL-6). No differences between the 2 groups were observed for serum C-reactive protein and IL-6 levels. LIMITATIONS Unblinded, relatively short follow-up; no formal sample-size calculations. CONCLUSIONS Use of a combination of 3 biocompatible PD fluids for 12 months compared with conventional PD fluid did not affect RRF, but was associated with better preservation of daily urine volume. The biocompatible PD fluids also lead to changes in small-solute transport and an increase in dialysate cancer antigen 125, IL-6, adiponectin, and systemic adiponectin levels, but have no effect on systemic inflammatory response. The clinical significance of these changes, while of great interest, remains to be determined by further studies.

Incidence and outcome of antiglomerular basement membrane disease in Chinese.

Background:  Antiglomerular basement membrane (anti‐GBM) disease is an uncommon disease, especially among Asian population. Many reports and studies on this condition in the Caucasian population are available, but little information exists on anti‐GBM disease in Asians. To study the incidence and clinical characteristics of anti‐GBM disease among Chinese patients, we reviewed our experience of anti‐GBM disease in our hospital (Queen Mary Hospital, Hong Kong) from 1992 to 2003.

CLINICAL COURSE AND OUTCOMES OF SINGLE-ORGANISM ENTEROCOCCUS PERITONITIS IN PERITONEAL DIALYSIS PATIENTS

♦ Background and Objectives: Enterococci are part of the normal flora of the gastrointestinal tract. They can cause enteric peritonitis, which is a serious complication of peritoneal dialysis (PD). However, the clinical course and outcome of PD-related Enterococcus peritonitis remains unclear. ♦ Methods: We reviewed all Enterococcus peritonitis episodes occurring in our dialysis unit from 1995 to 2009. ♦ Results: During the study period, 1421 episodes of peritonitis were recorded. Of 29 episodes (2.0%) that were attributable to single-organism Enterococcus, 12 episodes were caused by E. faecalis; 9, by E. faecium; and the remaining 8, by other Enterococcus species. The overall rate of ampicillin resistance was 41.4%. Recent use of antibiotics was associated with the development of ampicillin-resistant Enterococcus (ARE) peritonitis (hazard ratio: 12.53; p = 0.04). The primary response rate of Enterococcus peritonitis was significantly higher than that of Escherichia coli peritonitis (89.7% vs. 69.9%, p = 0.038), but the primary response rate was not significantly lower for ARE peritonitis than for ampicillin-susceptible Enterococcus (ASE) peritonitis (83.3% vs. 94.1%, p = 0.553). However, significantly more patients with ARE had received vancomycin (83.3% vs. 23.5%, p = 0.003), with a longer mean duration of vancomycin treatment (11.8 ± 6.9 days vs. 3.7 ± 6.8 days, p = 0.005). ♦ Conclusions: Recent use of antibiotics was a risk factor for the development of ARE peritonitis. Outcomes in ASE and ARE peritonitis were similar, but vancomycin was required during treatment for ARE peritonitis, in turn possibly predisposing the patients to infections caused by vancomycin-resistant organisms.

COLONIC DIVERTICULOSIS AS A RISK FACTOR FOR PERITONITIS IN CHINESE PERITONEAL DIALYSIS PATIENTS

♦ Objectives: The risk of development of enteric peritonitis in Chinese peritoneal dialysis (PD) patients with colonic diverticulosis is not known. There have been no reports on whether colonic diverticulosis may affect peritonitis outcomes. The objectives of this study were to examine whether colonic diverticulosis is a risk factor for the development of enteric peritonitis and to study its influence on the outcome of enteric peritonitis. ♦ Patients and Methods: All continuous ambulatory PD patients that had barium enema and colonoscopic examinations performed between January 1994 and January 2006 were included. They were divided into 2 groups: patients with diverticulosis and patients without diverticulosis. Their demographic and clinical characteristics, colonic examination findings, and peritonitis data were compared and analyzed. ♦ Results: 104 Chinese patients received 110 colonoscopies and 51 barium enema examinations. 25 patients (24.0%) had colonic diverticulosis. Patients with diverticulosis were older (65.4 ± 14.7 vs 58.4 ± 14.0 years, p = 0.033). The most common site of involvement of diverticulosis was the ascending colon (56%). 128 episodes of enteric peritonitis were recorded in 49 patients. Compared with patients without enteric peritonitis, more patients in the enteric peritonitis group had diverticulosis (38.8% vs 10.9%, p = 0.001) and diverticulosis most often involved the ascending colon (20.4% vs 7.3%, p = 0.082). Multivariate logistic regression analysis showed that the presence of diverticulosis (hazard ratio 5.17, 95% confidence interval 1.86 – 14.40; p = 0.002) and diverticulosis involving the ascending colon (hazard ratio 6.89, 95% confidence interval 1.43 – 33.32, p = 0.016) were independent risk factors for the development of enteric peritonitis. Enteric peritonitis in patients with diverticulosis had a higher but nonsignificant treatment failure rate (26.9% vs 18.4%, p = 0.282). ♦ Conclusion: In this selected cohort of PD patients with indications of colonic examinations, diverticulosis, especially involving the ascending colon, may be a risk factor for the development of enteric peritonitis. Colonic diverticulosis does not appear to affect the outcome of enteric peritonitis. Further studies are warranted to determine ways to prevent enteric peritonitis in PD patients with diverticulosis.

BODY MASS INDEX AND MORTALITY RISK IN ASIAN PERITONEAL DIALYSIS PATIENTS IN HONG KONG—IMPACT OF DIABETES AND CARDIOVASCULAR DISEASE STATUS

♦ Background: Obesity increases mortality in the general population, but improves survival in hemodialysis patients. In peritoneal dialysis (PD) patients, the reported effect is controversial. We investigated the effect of body mass index (BMI) on patient survival in Asian PD patients. ♦ Methods: The survival of incident Asian PD patients from 2001 to 2008 in a single center in Hong Kong was analyzed retrospectively. Baseline demographic and clinical data were collected from patient records. Patients who had a total Kt/V below 1.7 or who died within 6 months were excluded. The BMI was categorized using the World Health Organization recommendation for Asian populations. ♦ Results: In the 274 study patients [154 men (56%); 138 with diabetes (50.4%); mean age: 63.4 ± 14.6 years; mean BMI: 21.97 ± 3.23 kg/m2; 37 underweight (13.5%); 35 obese (12.8%)], the relative risk (RR) for mortality [adjusted for age, diabetes status, and cardiovascular disease (CVD)] was similar for the normal and overweight groups, but higher for the underweight (RR: 1.909; p = 0.028) and obese groups (RR: 1.799; p = 0.048). The increased mortality in obese patients was more prominent in patients with diabetes (RR: 1.9 vs 1.19 in patients without diabetes; p = 0.074 and 0.76 respectively), and in patients with CVD (RR: 8.895 vs 1.642 in patients without CVD; p = 0.012 and 0.122 respectively). ♦ Conclusions: In Asian PD patients, the relationship between BMI and mortality was U-shaped, with higher mortality in the underweight and obese patients. The negative impact of obesity was more prominent in patients with diabetes and CVD.

Seroprevalence of Helicobacter pylori in Chinese patients on continuous ambulatory peritoneal dialysis.

Backgrounds and Aims:  There is relatively little data on the seroprevalence of Helicobacter pylori in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). This study aims at establishing the seroprevalence of and the factors associated with H. pylori infection in Chinese CAPD patients.

Enhanced Psychosocial Support for Caregiver Burden for Patients With Chronic Kidney Failure Choosing Not to Be Treated by Dialysis or Transplantation: A Pilot Randomized Controlled Trial

BACKGROUND Family caregivers of patients with chronic kidney failure have increased burden, as reflected by their high frequency of physical and mental disturbances. The impact of enhanced psychosocial support to caregivers of patients with chronic kidney failure remains unclear. STUDY DESIGN Open-label randomized controlled trial. SETTING & PARTICIPANTS All new patients referred to the renal palliative clinic were screened. Caregivers of patients who met the following criteria were recruited: (1) chronic kidney failure as defined by creatinine clearance < 15 mL/min, (2) opted for conservative management by nephrology team or patient, (3) never treated with dialysis or transplantation, and (4) able to provide informed consent. INTERVENTIONS Random assignment to treatment with enhanced psychosocial support or standard renal care (control). Enhanced psychosocial support included counseling and psychosocial interventions by an on-site palliative care nurse and designated social worker. Each caregiver was followed up at 2- to 4-week intervals for up to 6 months. OUTCOMES Zarit Burden Inventory (ZBI) and Hospital Anxiety and Depression Scale (HADS) in caregivers and McGill Quality of Life scores in patients of both groups were compared. RESULTS 29 pairs of family caregivers/patients with chronic kidney failure were randomly assigned (intervention, n=14; control, n=15). Mean ages of patients and caregivers were 81.6 ± 5.1 and 59.8 ± 14.2 (SD) years, respectively. The intervention group showed significantly lower ZBI scores than the control group at 1 and 3 months (22.0 ± 5.3 vs 31.6 ± 9.5 and 21.3 ± 6.6 vs 33.4 ± 7.2; P=0.006 and P=0.009, respectively). HADS anxiety scores of caregivers who received the intervention were significantly lower than those of controls at 1 and 3 months (7.1 ± 3.2 vs 10.1 ± 2.2 and 6.5 ± 4.5 vs 11.0 ± 3.1; P=0.01 and P=0.03, respectively). Insignificant reductions in ZBI and HADS scores were found at 6 months. 19 patients died (intervention, n=10; control, n=9) during the study period. LIMITATIONS The study is limited by a relatively small sample size and short duration. CONCLUSIONS Enhanced psychosocial support program in patients with chronic kidney failure and caregivers resulted in an early significant reduction in caregiver burden and anxiety.

Cancer Incidence and Mortality in Chronic Dialysis Population: A Multicenter Cohort Study

Background: Different studies in the past have shown that the risk of cancer development is increased in chronic dialysis patients. However, data concerning the cancer risk in Asian dialysis patients was scarce. More importantly, there was lack of information about the cancer-specific mortality in dialysis patients. Methods: A multicenter retrospective cohort study of 6,254 patients who started either chronic peritoneal dialysis or hemodialysis between 1994 and 2014 in 4 renal units in Hong Kong. Patterns of cancer incidence and mortality in our dialysis patients were compared with those of the general population using standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) respectively. Results: With 14,887 person-years of follow-up, 220 cancers were recorded. The SIR of all cancers was 1.44 (95% CI 1.26-1.65). A trend of an increased SIR was observed in young patients and within the first year of dialysis. Colorectum was the most common site of cancer (20%) while kidney cancer carried the highest risk (SIR 12.28, 95% CI 8.44-17.08). The SMR of all cancers was 0.91 (95% CI 0.72-1.13) and only kidney cancer had higher cancer mortality risk (SMR 4.92, 95% CI 1.80-10.70). SMR was highest in young patients and then decreased with age. Conclusions: The incidence of cancers in our chronic dialysis patients was elevated. Our findings of substantially increased risks in young patients, particularly in relation to kidney cancer, suggest that we can adopt a more individualized approach to cancer screening in chronic dialysis patients.

A PROSPECTIVE RANDOMIZED STUDY COMPARING TENCKHOFF CATHETERS INSERTED USING THE TRIPLE INCISION METHOD WITH STANDARD SWAN NECK CATHETERS

♦ Background and Objective: The downward directed exit of the swan neck catheter may decrease the risk of exit-site infection (ESI). The percentage of migrations of the swan neck catheter seems to be less than the conventional Tenckhoff catheter and the swan neck catheter is more expensive and cannot be manipulated by guidewire technique if tip migration occurs. In this study, the conventional Tenckhoff catheter was used. The straight tunnel was converted to an arcuate one using the triple incision method, resulting in a downward directed exit. The arcuate tunnel was created by passing the catheter through an additional incision located between the paramedian incision and the exit site. We compared the infective and mechanical complications of the Tenckhoff catheter with a downward exit, implanted using the triple incision method, with the swan neck catheter. ♦ Patients and Methods: 101 new peritoneal dialysis patients were prospectively randomized to receive either the Tenckhoff catheter with a downward exit, implanted using the triple incision method, or the swan neck catheter. Each patient was followed up for 24 months. 50 patients were in the triple incision method group (TIMG) and 51 were in the swan neck catheter group (SNCG). ♦ Results: Over a mean period of 18.9 ± 8.0 months of follow-up, ESI occurred in 35 patients (70%) in TIMG and 37 patients (72.5%) in SNCG (p = 0.83). The ESI rates were 0.71 and 1.0 episodes/catheter-year in TIMG and SNCG respectively (p = 0.21). The peritonitis rates were similar in the 2 groups (0.64 episodes/year in TIMG and 0.68 episodes/year in SNCG, p = 0.47). More patients in TIMG had tip migration [15 patients (30%) in TIMG vs 10 patients (19.6%) in SNCG] but the difference was not statistically significant. Repositioning of the catheter by guidewire manipulation was successful in patients in TIMG but not in SNCG. Overall catheter survival at 12 and 24 months was 95% and 83% in TIMG and 93% and 79% in SNCG respectively (p = 0.72). ♦ Conclusion: By using the conventional Tenckhoff catheter with a downward exit created using the triple incision method, high catheter survival rates with infective and mechanical complication rates similar to those of the swan neck catheter can be achieved. The triple incision method has the additional advantages of lower cost and the catheter can be manipulated by guidewire technique if tip migration occurs.