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Chi Bon Leung

Publications and source records attributed to Chi Bon Leung.

13 recordsLinked to original sources
PubMed2007

Continuous ambulatory peritoneal dialysis peritonitis: broth inoculation culture versus water lysis method.

BACKGROUND/AIM: In the setting of empiric antibiotic treatment of peritoneal-dialysis-related peritonitis complications, the speed with which a bacteriological diagnosis can be achieved is of importance. We compare the clinical performance of two culture methods to diagnose the causative microorganisms as suggested by the International Society for Peritoneal Dialysis and the United Kingdom Health Protection Agency. METHODS: We prospectively evaluated microbiological cultures of peritoneal fluid samples by the direct broth culture versus water lysis. Samples from 17 consecutive patients with dialysis-associated peritonitis were examined. RESULTS: Of the 17 dialysates cultured, 14 (82.4%) were positive by one of the two methods. The final culture results agreed in 16 of 17 specimens (94.1%). The preliminary organism identification rate by Gram staining with the broth culture method was 70.6%, which was significantly greater than 17.6% by the water lysis method (p = 0.0019). In particular, the broth culture technique demonstrated superior Gram stain performance to identify Gram-positive organisms. Among the 13 dialysate samples positive by both methods, the broth culture method detected organisms faster than the water lysis method (1.3 +/- 0.7 vs. 2.6 +/- 1.6 days, p = 0.005). CONCLUSIONS: Our results support the routine use of the broth culture technique using BacT/Alert blood culture bottles in order to facilitate early streamlining of empiric antibiotic therapy. Gram staining of sediments after centrifugation is associated with low diagnostic yield. Whether the lysis-centrifugation technique could provide additional value in case of peritonitis with a high likelihood of culture-negative results needs to be evaluated.

Aged↗
PubMed2006

Adherence to peritoneal dialysis training schedule.

BACKGROUND: Shortening behaviour during peritoneal dialysis training can be easily measured, and likened to the skipping behaviour in haemodialysis subjects, although its effect on peritoneal dialysis outcomes is now well understood. We studied the clinical impact of failing to adhere to a peritoneal dialysis training programme among incident dialysis patients. METHODS: This study included 159 consecutive inception peritoneal dialysis patients in a single centre from September 1999 through November 2002. We evaluated the effects of behavioural compliance quantified by the per cent time arriving late for scheduled peritoneal dialysis training. The patients were categorized by whether they arrived late in >20% of their peritoneal dialysis training sessions. RESULTS: Of the 159 incident peritoneal dialysis patients (mean age 57 +/- 13 years) who attended peritoneal dialysis training, 70 subjects (44%) arrived late in >20% of the sessions. They were younger by 5 years than patients who arrived late < or =20%. Mean peritonitis-free time for subjects who arrived late for training in >20% the of sessions was 30.9 months, as compared with 41.8 months in subjects with < or =20% late attendance behaviour (log rank test, P = 0.038). Multivariable Cox proportional hazards analysis showed that late attendance behaviour and baseline serum albumin were the only independent risk factors for the time to a first peritonitis after adjustment for diabetes mellitus and relevant coexisting medical factors. Late arrival in >20% of the peritoneal dialysis training sessions was associated with >50% increased likelihood of subsequent peritonitis, with an adjusted risk ratio of 1.56 (95% confidence interval, 1.02-2.39; P = 0.04). CONCLUSION: These findings show that the behavioural measure of late attendance for peritoneal dialysis training has a crucial role in predicting peritonitis. It may therefore represent a practical strategy for identifying poor adherence or predicting medical outcomes.

Adolescent↗
PubMed2006

Antibody response to hepatitis B vaccine in end-stage renal disease patients.

BACKGROUND: This retrospective and comparative study evaluated the relationship between different factors which may contribute to suboptimal immunological response to intramuscular recombinant hepatitis B vaccine in end-stage renal disease (ESRD) subjects. METHODS: From a cohort of 64 dialysis subjects undergoing primary vaccination with Engerix-B, we determined the predictive factors that impinged on patients' response to vaccine, as defined by anti-HBs level > or = 10 mIU/l. Dose efficacy was further evaluated by comparing three historical cohorts vaccinated by the regimens of 20, 40 and 80 microg/dose, respectively. RESULTS: We identified 64 ESRD patients (mean age 43 +/- 12 years, 81% receiving peritoneal dialysis) who received primary vaccination from April 1997 to September 2004. Median follow-up was 6.5 years. They achieved 81% seroconversion rate. Older age, diabetes mellitus, obesity and low Engerix-B dose were risk factors of inadequate anti-HBs response by univariate analysis. By stepwise logistic regression analysis, hepatitis B vaccine dose was the only independent predictive factor of impaired antibody response. An Engerix-B vaccine dose of 20 microg was associated with more than tenfold increase in risk of non-response to hepatitis B vaccine (hazards ratio 32.2 (95% CI 3.85-250.0)). Immunization with 80 microg of Engerix-B increased the likelihood of persistent protective antibody (log-rank test, p = 0.014). Immunization with Engerix-B 80-microg dose is estimated to prevent one extra ESRD subject who would lose seroprotective anti-HBs level at 1 year for every 5.6 patients treated (number needed to treat to benefit, 5.6 (95% CI 5.4-5.8)). CONCLUSIONS: Our results suggest the potential for the three-dose schedule of recombinant vaccine Engerix-B 80 microg to prolong the immune response among ESRD population.

Adult↗
PubMed2006

Hong Kong study using valsartan in IgA nephropathy (HKVIN): a double-blind, randomized, placebo-controlled study.

BACKGROUND: Previous studies showed that angiotensin-receptor blocker (ARB) therapy decreased proteinuria and possibly slowed the rate of renal function decline in patients with chronic proteinuric nephropathies. We performed a double-blind, randomized, placebo-controlled, multicenter study on the ARB valsartan in the treatment of patients with immunoglobulin A (IgA) nephropathy. METHODS: From 6 centers, we recruited 109 patients with IgA nephropathy who had either: (1) proteinuria with protein greater than 1 g/d and serum creatinine level less than 2.8 mg/dL (< 250 micromol/L), or (2) serum creatinine level of 1.4 to 2.8 mg/dL (120 to 250 micromol/L) regardless of degree of proteinuria. Patients were randomly assigned to administration of either valsartan, 80 mg/d (titrated up to 160 mg/d for blood pressure control), or placebo for 104 weeks. Additional antihypertensive therapy was allowed to achieve a target blood pressure of 140/90 mm Hg. The primary end point was doubling of serum creatinine level or dialysis-dependent renal failure. Secondary outcomes included change in proteinuria and decrease in glomerular filtration rate (GFR). RESULTS: There were 54 patients in the treatment group and 55 patients in the placebo group. Baseline clinical characteristics were similar between groups, although the treatment group had a marginally greater baseline GFR (87 +/- 36 versus 78 +/- 38 mL/min/1.73 m2 [1.45 +/- 0.60 versus 1.30 +/- 0.63 mL/s/1.73 m2];P = 0.29) and less proteinuria (protein, 1.8 +/- 1.2 versus 2.3 +/- 1.7 g/d; P = 0.21) than the placebo group. Average blood pressures during the study were 92.7 +/- 10.6 mm Hg in the treatment group and 100.9 +/- 9.1 mm Hg in the placebo group (P < 0.001). During the study period, 4 patients in the placebo group and 1 patient in the treatment group reached the primary end point (log-rank test, P = 0.18). Proteinuria decreased significantly in the treatment group (protein, 1.8 +/- 1.2 to 1.2 +/- 1.2 g/d; P = 0.03), but did not change in the placebo group. With multiple linear regression models, valsartan treatment resulted in a 33.0% decrease in proteinuria (95% confidence interval, 10.9 to 55.1) after adjusting for other confounding factors. There was a significant decrease in mean rate of GFR decrease in the valsartan-treated group (-5.62 +/- 6.79 mL/min/y [-0.09 +/- 0.11 mL/s/y]) compared with the placebo group (-6.98 +/- 6.17 mL/min/y [-0.12 +/- 0.10 mL/s/y]) throughout the study period after adjustment for average blood pressure and proteinuria (P = 0.014). CONCLUSION: Valsartan significantly decreases proteinuria and slows renal deterioration in patients with IgA nephropathy after adjustment for confounding factors, notably blood pressure. The long-term benefit of valsartan needs to be confirmed with additional studies.

Adult↗
PubMed2005

Impact of social factors on patients on peritoneal dialysis.

BACKGROUND: Clinical outcomes among patients on peritoneal dialysis (PD) might not be linked to medical factors alone. We studied the clinical impact of various social factors among patients on PD. METHODS: In a cohort of 102 consecutive patients who started PD in a single centre between 2003 and 2004, we evaluated the effects of social factors on the development of peritonitis and risk of hospitalization after initiation of PD. RESULTS: Of 102 incident PD patients, 35 subjects (34.3%) were referred to nephrologists more than 3 months before dialysis initiation. During 85.7 patient-years of observation (median follow-up, 10.7 months), four subjects died and six underwent kidney transplantation. Patients receiving social security assistance and those younger than 40 years fared worse than others in terms of their risk of peritonitis. Mean peritonitis-free time for subjects who were on social security assistance was 2.7 months, and for those who were not, 16.4 months (P = 0.045). In the Cox proportional hazards analysis, need for social security assistance and illiteracy were the only statistically significant factors associated with the time to a first peritonitis, after adjustment for social characteristics and relevant coexisting medical factors. Dependence on social security assistance prior to PD was associated with a >2-fold increased likelihood of peritonitis, with an adjusted risk ratio of 2.69 (95% confidence interval, 1.10 to 6.54; P = 0.029). The total number of hospitalization days was similar between those who received social security assistance and those who did not: 17.4+/-14.6 days (range, 4-50 days) vs 17.9+/-14.0 days (range, 0-60 days) (P = 0.89). CONCLUSIONS: Our results confirm that socioeconomic status is closely associated with the rate of peritonitis among PD patients. The long-term reliability of these social predictors remains to be validated.

Adult↗
PubMed2005

Prevalence of silent kidney disease in Hong Kong: the screening for Hong Kong Asymptomatic Renal Population and Evaluation (SHARE) program.

BACKGROUND: End-stage renal disease (ESRD) is epidemic worldwide. In Hong Kong, the annual incidence of ESRD has risen from 100 pmp (per million population) in 1996 to 140 pmp in 2003. SHARE (Screening for Hong Kong Asymptomatic Renal Population and Evaluation program) is a population-based screening program aimed at identifying the prevalence of unrecognized renal disease in asymptomatic individuals, allowing further evaluation and disease-modifying interventions. METHODS: From November to December 2003, SHARE was conducted in several large residential communities in Hong Kong. The screening tool included a questionnaire documenting demographics and history or family history of diabetes mellitus (DM), hypertension (HT), and chronic kidney disease (CKD), together with on-site measurements of blood pressure (BP) and urine dipstick for protein, blood, and glucose. RESULTS: There were a total of 1811 participants. One thousand two hundred and one subjects were entered into the final analysis. Among the 1201 who were apparently "healthy" (asymptomatic and without history of DM, HT, or CKD), the prevalence of positive (> or =1+) urine dipstick for protein, glucose, blood, protein or blood, any urine abnormality, and HT (BP> or =140/90) was 3.2%, 1.7%, 13.8%, 16%, 17.4%, and 8.7%, respectively. Thirty three percent of the age over 60 years old group had either hypertension or urine abnormalities, compared with 24.0% in the 41- to 60-year-old group and 9.7% in the 20- to 40-year-old group. Having a family history of diabetes or hypertension increases the risk of having urine abnormalities, while a family history of hypertension also increases the risk of high blood pressure. CONCLUSION: It is concluded that subclinical abnormalities in urinalysis or BP readings are prevalent across all age groups in the adult population. An effective screening program at the primary care level that identifies these subjects for further evaluation is warranted, and the public in Hong Kong should be educated toward the significance of such findings in order to have regular health check for asymptomatic renal diseases.

Adult↗
PubMed2003

Quantitative analysis of pleural fluid cell-free DNA as a tool for the classification of pleural effusions.

BACKGROUND: Recently, much interest has been focused on the quantification of DNA in miscellaneous body fluids. In this study, the application is extended to classifying pleural effusions by measuring cell-free DNA in pleural fluid. METHODS: We recruited 50 consecutive patients with pleural effusions with informed consent. Pleural fluids were centrifuged at 13000 g, with supernatants aliquoted for extraction and analysis of beta-globin DNA sequence by quantitative real-time PCR. Serum and pleural fluid biochemistries were performed to classify pleural effusions using the modified criteria of Light et al. (Ann Intern Med 1972;77:507-13). The ROC curve was plotted to determine the cutoff DNA concentration for classifying pleural fluids as transudates or exudates. Indicators of diagnostic accuracy were calculated for both pleural fluid DNA and modified criteria of Light et al., using the discharge, microbiologic, and histologic diagnoses as the reference standard. RESULTS: The area under the ROC curve was 0.95 [95% confidence interval (CI), 0.84-0.99]. At 509 genome-equivalents/mL, pleural fluid DNA alone correctly classified 46 of 50 pleural effusions with 91% sensitivity (95% CI, 76-98%), 88% specificity (95% CI, 64-98%), and positive and negative likelihood ratios of 7.7 (95% CI, 3.1-19.5) and 0.10 (95% CI, 0.04-0.27), respectively. With the modified criteria of Light et al., 43 of 50 pleural effusions were correctly classified with 97% sensitivity (95% CI, 91-100%) and 67% specificity (95% CI, 45-89%). There were significant correlations between cell-free DNA and both lactate dehydrogenase and total protein in pleural fluid, suggesting their common origin. CONCLUSIONS: Pleural fluid DNA concentrations are markedly increased in exudative effusions, making it a potential new tool to evaluate the etiologic causes of pleural effusions.

Adolescent↗
PubMed2002

Comparison of clinical outcome and ease of handling in two double-bag systems in continuous ambulatory peritoneal dialysis: a prospective, randomized, controlled, multicenter study.

BACKGROUND: We performed a prospective, randomized, controlled, multicenter study on the use of two double-bag disconnect systems: Stay-Safe (SS; Fresenius Deutschland GmbH2) and Ultrabag (UB; Baxter Healthcare, Deerfield, IL) to assess the ease of handling, peritonitis rate, exit-site infection rate, and clinical outcome. METHODS: We enrolled 110 new continuous ambulatory peritoneal dialysis (CAPD) patients; 55 patients were randomized to SS treatment, and 55 patients, to UB treatment. RESULTS: Patients using the UB and SS systems were followed up for 946 and 846 patient-months, respectively. There were 21 episodes of peritonitis in 18 patients in the UB group and 23 episodes in 18 patients in the SS group. No significant difference was observed in peritonitis rates between the two systems, which were 45 and 36.8 patient-months per episode for the UB and SS groups, respectively. At 12 months, 82.1% of patients in the UB group and 72.1% in the SS group were free of peritonitis; at 18 months, 71.1% and 62.2% were free of peritonitis for the UB and SS groups, respectively (P = 0.559). Gram-positive organisms accounted for 28.6% of infections in the UB group and 39.1% in the SS group. Exit-site infection rates were one episode per 21 patient-months versus 19.2 patient-months in the UB and SS groups, respectively (P = 0.743). Patients perceived SS as easier to handle in 4 of the 13 steps immediately post-CAPD training. However, there was no significant difference in rankings between the two systems after 1 month of adaptation. Median training periods were 4 and 5 days for the SS and UB groups, respectively (P = 0.640). CONCLUSION: The two double-bag systems (UB and SS) have similar incidences of peritonitis and exit-site infection. Both systems showed comparably good clinical outcome. The SS system is easier to learn during the initial training period, but the difference is not significant after 1 month's adaptation.

Catheters, Indwelling↗
PubMedDate not supplied

Body mass index as a predictive factor for long-term renal transplant outcomes in Asians.

BACKGROUND: There is substantial evidence that renal transplant recipients with obesity or body mass index >30 kg/m(2) have increased risk of graft loss. However, few data exist for Asian population; clinicians have to rely upon indirect evidence by extrapolating the results from Caucasians to Asian recipients. STUDY: Using data from a study population of 150 consecutive cadaveric or living related Chinese renal transplant recipients at our center between 1985 and 2002, we examined the effect of baseline body mass index cut-off 25 kg/m(2) on the transplant outcomes using Kaplan-Meier analysis and Cox proportional hazards analysis. Primary study end point was overall graft survival. RESULTS: The mean body mass index was 22.9 +/- 4.0 kg/m(2). Thirty-seven (25%) patients were classified as overweight and 113 patients as non-overweight, using the cut-off of 25 kg/m(2). After median follow up period of nine yr, 15 graft losses (41%) occurred in the overweight group, as compared with 14 graft losses (12%) in the non-overweight group. Kaplan-Meier estimates of cumulative graft survival at five yr were significantly worse for the overweight group than non-overweight group (83.6% versus 92.7%, p = 0.0041). By multivariate Cox proportional hazards analysis, baseline body mass index > or =25 kg/m(2) conferred a significantly higher risk of graft loss (with relative risk of 4.78, 95% CI = 1.52-15.2) and doubling of serum creatinine (relative risk 3.19, 95% CI = 1.22-8.40). Death with a functioning graft occurred in 11% of overweight recipients, compared with 3% among the non-overweight group (p = 0.041). CONCLUSION: Our results draw attention to a recipient body mass index cut-off value > or =25 kg/m(2), which might confer an increased risk of graft loss in Asian kidney transplant populations.

Asian People↗
PubMedDate not supplied

Improved health-related quality of life and left ventricular hypertrophy among dialysis patients treated with parathyroidectomy.

BACKGROUND: We prospectively studied changes in the perception of health-related quality of life, pruritus, and degree of left ventricular hypertrophy in end-stage renal disease patients with tertiary hyperparathyroid disorder, before and 6 months after total parathyroidectomy treatment. METHODS: A series of 12 consecutive patients were enrolled. Throughout the follow-up period, all subjects completed the Kidney Disease Quality of Life Short Form-36 (KDQOL SF-36) questionnaire at inclusion and after 6 months. Serial clinical and physiological parameters including uremic pruritus, blood pressure control and left ventricular hypertrophy measured by echocardiography were recorded. RESULTS: Mean scores of the KDQOL SF-36 questionnaires were substantially higher 6 months after parathyroidectomy, with reference to physical functioning, bodily pain, role-physical, role-emotional, symptom list and burden of kidney disease. Parathyroidectomy resulted in a 22% reduction in left ventricular mass index, with significant improvement from the baseline value of 246 +/- 131 to 192 +/- 131 g/m2 (p = 0.03). CONCLUSION: Our findings highlight the potential importance of parathyroidectomy in improving health-related quality of life and left ventricular hypertrophy among dialysis patients with tertiary hyperparathyroidism.

Female↗
PubMedDate not supplied

A risk analysis of continuous ambulatory peritoneal dialysis-related peritonitis.

OBJECTIVE: We studied the clinical characteristics that influence the risk of dialysis-related peritonitis complication in incident Chinese patients undergoing continuous ambulatory peritoneal dialysis (CAPD). METHODS: A single center, retrospective, observational cohort study was carried out to examine the risk factors of developing a first episode of dialysis-related peritonitis. RESULTS: Between 1995 and 2004, 246 incident CAPD patients were recruited for analysis. During the study period of 897.1 patient-years, 85 initial episodes of peritonitis were recorded. The median peritonitis-free time for diabetic subjects was significantly worse than for nondiabetic subjects (49.0 +/- 10.5 vs 82.3 +/- 12.6 months, p = 0.0019). The difference was due mainly to a higher likelihood of developing peritonitis with gram-negative organisms in patients with diabetes mellitus (p = 0.038). Low serum albumin concentration was also associated with worse peritonitis-free survival. There was a nonsignificant trend toward an increased risk for peritonitis in the group of patients with cerebrovascular disease. According to multivariate Cox proportional hazards model for the analysis of time to first peritonitis episode, the two independent risk factors were presence of diabetes mellitus and initial serum albumin concentration. In particular, diabetes mellitus was associated with a hazard ratio of 1.50 and a 95% confidence interval of 1.05 - 2.40 (p = 0.030) to develop an initial peritonitis. Lower serum albumin level at the start of CAPD was a significant predictor of peritonitis, with hazard ratio of 1.67 for every decrease of 10 g/L, and 95% confidence interval 1.08 - 2.60 (p = 0.021). CONCLUSIONS: Our results confirm the susceptibility of diabetic CAPD and hypoalbuminemic patients to peritonitis, and highlight the role of further studies in reducing this complication.

Adolescent↗
PubMedDate not supplied

Continuous ambulatory peritoneal dialysis in patients with hepatitis B liver disease.

OBJECTIVE: We hypothesized that patients with hepatitis B virus infection and cirrhosis are more susceptible to peritonitis as a complication of peritoneal dialysis (PD). METHODS: A retrospective study was carried out to compare peritonitis rates between cirrhotic and non-cirrhotic patients with hepatitis B virus infection. RESULTS: Between 1994 and 2004, 25 PD patients with hepatitis B cirrhosis and 36 patients with hepatitis B without cirrhosis were included for analysis. Mean follow-up duration was 52 months. Subjects with hepatitis B cirrhosis consisted of more males and had higher total body weight. No cirrhotic patients (20 of them being Child-Pugh class A, 2 class B, and 3 class C) had undergone portosystemic shunting or liver transplantation. Cirrhotic patients had slightly higher bilirubin concentration than the non-cirrhotic group (22 +/- 50 vs 9 +/- 4 micromol/L, p = 0.16). There was no difference in median peritonitis-free survival between cirrhotic and non-cirrhotic patients (40 vs 37 months, p = 0.64 by log-rank test). The average peritonitis rate was 1 episode every 19.2 patient-months in the cirrhotic group and 1 episode every 20.5 patient-months in the non-cirrhotic group. Time to first peritonitis did not differ between the two groups with respect to gram-negative organisms (p = 0.88) or gram-positive organisms (p = 0.52). Cirrhotic patients had more frequent Streptococcus species peritonitis, which accounted for 13% of all peritonitis episodes, as opposed to 2% among the non-cirrhotic patients (p = 0.01). Overall treatment response rate and outcome did not differ between patients with and patients without cirrhosis. CONCLUSIONS: Peritonitis-free survival of cirrhosis patients infected by hepatitis B virus compares favorably with thatin patients without cirrhosis. The presence of liver cirrhosis does not appear to compromise PD outcome.

Female↗