B Lam

The University of Hong Kong, Hong Kong, Hong Kong

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Publications (69)327.78 Total impact

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    ABSTRACT: Nocturnal rostral fluid shift has been suggested to be a risk factor for obstructive sleep apnea (OSA) in healthy subjects after lower body positive pressurization. It remains unclear whether this may apply to subjects with nephrotic lower limb edema and, if so, whether disease remission may reverse the accompanying OSA. Patients who presented with steroid-responsive primary nephrotic syndrome with lower limb edema as the predominant presenting clinical feature were recruited. They underwent one overnight polysomnography (PSG) before treatment and a repeat testing after achieving remission of the nephrotic edema. Among 23 consecutive nephrotic subjects, 11 (48%) had polysomnographic evidence of sleep apnea [apnea-hypopnea index (AHI)≥5] upon presentation. After steroid-based treatment, there was remission of proteinuria associated with complete disappearance of lower limb edema, significant reduction of body mass index, waist, hip and calf circumferences and total body water mainly in the extracellular compartment. Repeat PSG, performed 8.1±2.6 months later, showed that the overall (N=23) respiratory disturbance index (RDI) and AHI fell from 17.3±5.0 to 8.7±2.5 (P<0.05) and from 16.3±5.1 to 7.8±2.3 (P=0.057), respectively. Among the 11 subjects with sleep apnea detected at baseline, their AHI and RDI fell from 33.4±7.8 to 15.0±3.7 (P<0.05) and from 34.8±7.6 to 16.5±4.0 (P<0.05), respectively. There was also concomitant improvement in sleep efficiency, mean nocturnal oxygen saturation, shorter duration during sleep with oxygen saturation<95 and <90% and reduced desaturation index. There was also subjective improvement in self-reported daytime sleepiness. Nephrotic lower limb edema is associated with disturbed respiratory breathing and increased propensity to OSA, which was reversed upon remission of the nephrosis. This gathers a unifying concept for the role of nocturnal rostral fluid shift in the pathogenesis of OSA.
    Nephrology Dialysis Transplantation 01/2012; 27(7):2788-94. · 3.37 Impact Factor
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    ABSTRACT: Smokers with silicosis are at increased risk of lung cancer. To evaluate the feasibility of using autofluorescence bronchoscopy after sputum examination for early detection of large airway lung cancer and factors associated with the presence of cancerous and pre-cancerous lesions among smokers with silicosis. Subjects at the pneumoconiosis clinic were recruited if they fulfilled the following criteria: 1) age ≥40 years, 2) smoking history of ≥20 pack-years and 3) confirmed diagnosis of silicosis. Sputum specimens were collected for cytology/cytometry examination and autofluorescence bronchoscopy was performed in subjects with an abnormal sputum result. A total of 48 subjects were recruited during the study period. The mean age and smoking history were respectively 63 ± 10 years and 51 ± 30 pack-years. Intraepithelial lung cancers and pre-neoplastic lesions (squamous metaplasia or above) were detected in respectively 2 (4.2%) and 14 (29.2%) subjects. The proportions of current smokers (75.0% vs. 40.6%, P = 0.03) and asbestos exposure (37.5% vs. 9.4%, P = 0.04) were significantly higher in subjects with the above lesions compared with those without. Sputum examination followed by autofluorescence bronchoscopy may be a useful way of identifying cancerous/pre-cancerous lesions among silicotic smokers. Current smoking and asbestos exposure were associated with these lesions.
    The international journal of tuberculosis and lung disease: the official journal of the International Union against Tuberculosis and Lung Disease 04/2011; 15(4):523-7. · 2.61 Impact Factor
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    ABSTRACT: The practice of pleurodesis for the management and prevention of spontaneous pneumothorax (SP) is uncertain. A retrospective multicentre analysis of patients admitted to 12 hospitals in Hong Kong with SP in 2004 and who subsequently underwent pleurodesis for the same episode. Pleurodesis was performed in 394 episodes. Initial medical chemical pleurodesis was performed for 258 (65.5%) patients ('initial medical group'), while 136 (34.5%) underwent initial surgical pleurodesis ('initial surgical group'). Secondary spontaneous pneumothorax (SSP; 237 episodes, 60.2%) was the most common indication for pleurodesis; it was also performed after a first episode of primary spontaneous pneumothorax (PSP) in 22 episodes (5.6%). Tetracycline derivatives (172 episodes, 66.7%) were the most popular sclerosing agents in the initial medical group. Those in the initial medical group were older and were more likely to be males, have SSP, chronic obstructive pulmonary disease and a history of past pleurodesis (P < 0.05) compared to the initial surgical group. Compared to the tetracycline group, more patients who initially received talc slurry had the procedure performed by surgeons, had larger (≥2 cm) pneumothorax or required suction during initial drainage (P < 0.05). Despite the availability of international guidelines, there is considerable variation in pleurodesis for SP.
    The international journal of tuberculosis and lung disease: the official journal of the International Union against Tuberculosis and Lung Disease 03/2011; 15(3):385-90. · 2.61 Impact Factor
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    ABSTRACT: BACKGROUND: The practice of pleurodesis for the management and prevention of spontaneous pneumothorax (SP) is uncertain.DESIGN: A retrospective multicentre analysis of patients admitted to 12 hospitals in Hong Kong with SP in 2004 and who subsequently underwent pleurodesis for the same episode.RESULTS: Pleurodesis was performed in 394 episodes. Initial medical chemical pleurodesis was performed for 258 (65.5%) patients (`initial medical group'), while 136 (34.5%) underwent initial surgical pleurodesis (`initial surgical group'). Secondary spontaneous pneumothorax (SSP; 237 episodes, 60.2%) was the most common indication for pleurodesis; it was also performed after a first episode of primary spontaneous pneumothorax (PSP) in 22 episodes (5.6%). Tetracycline derivatives (172 episodes, 66.7%) were the most popular sclerosing agents in the initial medical group. Those in the initial medical group were older and were more likely to be males, have SSP, chronic obstructive pulmonary disease and a history of past pleurodesis (P < 0.05) compared to the initial surgical group. Compared to the tetracycline group, more patients who initially received talc slurry had the procedure performed by surgeons, had larger (≥2 cm) pneumothorax or required suction during initial drainage (P < 0.05).CONCLUSIONS: Despite the availability of international guidelines, there is considerable variation in pleurodesis for SP.
    The international journal of tuberculosis and lung disease: the official journal of the International Union against Tuberculosis and Lung Disease 02/2011; 15(3):385-390. · 2.61 Impact Factor
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    ABSTRACT: Bronchiolitis obliterans syndrome (BOS) is an important complication after hematopoietic SCT (HSCT). Recent observations suggested that azithromycin might improve lung function in BOS after HSCT. We conducted a randomized double-blinded placebo-controlled study on azithromycin in patients with BOS after HSCT. The treatment group (n=10) received oral azithromycin 250 mg daily while the control group (n=12) received placebo daily for 12 weeks. Respiratory symptoms were assessed by the St George Respiratory Questionnaires and spirometry at baseline (drug commencement), 1, 2, 3 (drug cessation) and 4 months (1 month after drug cessation). There was no significant difference in the baseline demographic characteristics between the treatment and the control groups in age, gender, time from HSCT to BOS, time since diagnosis of BOS, chronic GVHD, baseline respiratory symptom scores and baseline forced expiratory volume in 1 s (FEV(1)). Throughout and after 3 months of treatment, there were no significant changes in respiratory symptom scores and FEV(1) measurements between the treatment and the control groups. In conclusion, there was no significant benefit of 3 months of oral azithromycin on the respiratory symptoms and lung function in patients with relatively late BOS after HSCT in this randomized placebo-controlled study.
    Bone marrow transplantation 02/2011; 46(12):1551-6. · 3.00 Impact Factor
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    ABSTRACT: The purpose of this study is to evaluate the efficacy of oral appliance (OA) treatment for subjects with severe obstructive sleep apnea (OSA) and to determine the dental parameters associated with treatment outcomes. This study uses a prospective longitudinal design. Consecutive Chinese subjects with severe OSA who refused continuous positive airway pressure treatment were recruited. Their dental measurements were taken from lateral cephalometric radiographs. Polysomnograms with OA were repeated at 3 months and 1 year. Blood pressure was taken in the morning after sleep studies. Thirty-four subjects were evaluated at 3 months and 1 year according to the principle of intention-to-treat analysis. OA reduced AHI significantly in subjects with favorable responses, from 49.3 (37.4-67) to 12.5 (6.1-15.7), p < 0.001 at 3 months and from 47.5 (41.1-72.9) to 13.1 (6.0-14.0), p < 0.001 at 1 year. These OSA subjects had an increased overjet at baseline compared to those with unfavorable responses (p ≤ 0.05). Systolic blood pressure was significantly reduced in those hypertensive OSA subjects after 3 months and 1 year of treatment. OA reduces the severity of sleep apnea, and the effect is maintained at 1 year in subjects with retrognathism. OA appears to reduce systolic blood pressure in hypertensive OSA subjects at 3 months and 1 year.
    Sleep And Breathing 02/2011; 15(2):195-201. · 2.26 Impact Factor
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    ABSTRACT: Few studies have evaluated the sclerosing efficacy of minocycline, and none have specifically compared its sclerosing efficacy and safety profiles with talc slurry in secondary spontaneous pneumothorax (SSP). A retrospective analysis was conducted in patients with SSP who underwent chemical pleurodesis from January to December 2004 with minocycline or talc slurry in 12 public hospitals of Hong Kong. There were 121 episodes of minocycline pleurodesis and 64 episodes of talc slurry pleurodesis. Immediate procedural failure were similar in the minocycline and talc slurry groups (21.5% vs. 28.1%, P = 0.31). Presence of interstitial lung disease, ≥ 2 previous episodes of pneumothorax, requiring mechanical ventilation during pleurodesis and persistent air leak before pleurodesis were independently associated with procedural failure. Pain was experienced in respectively 44.6% and 37.5% of the minocycline and the talc slurry groups. Pain was more common in patients receiving high doses of talc (≥ 5 g; P = 0.03). Respiratory distress was found in respectively 1.7% and 1.6% of the minocycline and talc slurry groups. Minocycline and talc slurry had comparable sclerosing efficacy in SSP, with immediate success rates of >70%. Pain was the most common adverse effect and respiratory distress was uncommon. Both appeared to be effective and safe for chemical pleurodesis in SSP.
    The international journal of tuberculosis and lung disease: the official journal of the International Union against Tuberculosis and Lung Disease 10/2010; 14(10):1342-6. · 2.61 Impact Factor
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    ABSTRACT: SETTING: Few studies have evaluated the sclerosing efficacy of minocycline, and none have specifically compared its sclerosing efficacy and safety profiles with talc slurry in secondary spontaneous pneumothorax (SSP).DESIGN: A retrospective analysis was conducted in patients with SSP who underwent chemical pleurodesis from January to December 2004 with minocycline or talc slurry in 12 public hospitals of Hong Kong.RESULT: There were 121 episodes of minocycline pleurodesis and 64 episodes of talc slurry pleurodesis. Immediate procedural failure were similar in the minocycline and talc slurry groups (21.5% vs. 28.1%, P = 0.31). Presence of interstitial lung disease, ≥2 previous episodes of pneumothorax, requiring mechanical ventilation during pleurodesis and persistent air leak before pleurodesis were independently associated with procedural failure. Pain was experienced in respectively 44.6% and 37.5% of the minocycline and the talc slurry groups. Pain was more common in patients receiving high doses of talc (≥5 g; P = 0.03). Respiratory distress was found in respectively 1.7% and 1.6% of the minocycline and talc slurry groups.CONCLUSION: Minocycline and talc slurry had comparable sclerosing efficacy in SSP, with immediate success rates of >70%. Pain was the most common adverse effect and respiratory distress was uncommon. Both appeared to be effective and safe for chemical pleurodesis in SSP.
    The international journal of tuberculosis and lung disease: the official journal of the International Union against Tuberculosis and Lung Disease 09/2010; 14(10):1342-1346. · 2.61 Impact Factor
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    ABSTRACT: Sleep apnea syndrome is increasingly recognized in peritoneal dialysis patients; however, its prognostic implication in this population is unknown. To study this, we prospectively followed the clinical outcome of 93 peritoneal dialysis patients with baseline polysomnography. Of these, 51 were diagnosed with the syndrome defined by an apnea-hypopnea index (AHI) of at least 15 per hour. During a median follow-up of 41 months, there were 30 deaths, of which 17 were due to cardiovascular causes. Kaplan-Meier analysis for the entire follow-up period indicated that patients with sleep apnea at baseline had significantly higher all-cause and cardiovascular mortality during follow-up than those without. Minimal nocturnal saturation and desaturation indices were predictors of mortality and cardiovascular events at univariate analysis. Multivariable Cox regression analysis identified significant sleep apnea syndrome at baseline as an independent predictor of increased all-cause mortality independent of age, male gender, and diabetic status. Further, an absolute increase in the AHI was associated with an incremental risk of cardiovascular events. Thus, sleep apnea syndrome, detected at the start of peritoneal dialysis, is a novel risk predictor for subsequent mortality and cardiovascular events.
    Kidney International 03/2010; 77(11):1031-8. · 7.92 Impact Factor
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    ABSTRACT: Obstructive sleep apnoea (OSA) is increasingly being recognized as an important health issue in the last two to three decades. It is characterized by frequent episodes of upper airway collapse during sleep, causing recurrent arousals, intermittent hypoxaemia, sleep fragmentation and poor sleep quality. There is accumulating evidence that OSA is being considered as an independent risk factor for hypertension, glucose intolerance / diabetes mellitus, cardiovascular diseases and stroke, leading to increased cardiometabolic morbidity and mortality. The prevalence rates of OSA have been estimated in the range of 2 to 10 per cent worldwide, and the risk factors for obstructive sleep apnoea include advanced age, male sex, obesity, family history, craniofacial abnormalities, smoking and alcohol consumption. The common clinical presenting symptoms are heavy snoring, witnessed apnoeas and daytime hypersomnolence, which would help to identify the affected individuals. With increasing awareness of this disease entity and associated complications in our society, there have been increased referrals to sleep physicians or expertise for further investigations and diagnostic evaluation. Early recognition and treatment of obstructive sleep apnoea may prevent from adverse health consequences. Some of the epidemiological aspects of obstructive sleep apnoea in adults are reviewed.
    The Indian Journal of Medical Research 02/2010; 131:165-70. · 2.06 Impact Factor
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    ABSTRACT: To examine the management practice of pneumothorax in hospitalised patients in Hong Kong, especially the choice of drainage options and their success rates, as well as the factors associated with procedural failures. Retrospective study. Multi-centre study involving 12 public hospitals in Hong Kong. All adult patients admitted as an emergency in the year 2004 with a discharge diagnosis of 'pneumothorax' were included. Data on the management and outcomes of the various types of pneumothoraces were collected from their case records. Altogether these patients had 1091 episodes (476 primary spontaneous pneumothoraces, 483 secondary spontaneous pneumothoraces, 87 iatrogenic pneumothoraces, and 45 traumatic pneumothoraces). Conservative treatment was offered in 182 (17%) episodes, which were more common among patients with small primary spontaneous pneumothoraces (71%). Simple aspiration was performed to treat 122 (11%) of such episodes, and had a success rate of 15%. Aspiration failure was associated with having a pneumothorax of size 2 cm or larger (odds ratio=3.7; 95% confidence interval, 1.2-11.5; P=0.03) and a smoking history (4.1; 1.2-14.3; P=0.03). Intercostal tube drainage was employed in 890 (82%) episodes, with a success rate of 77%. Failure of intercostal tube drainage was associated with application of suction (odds ratio=4.1; 95% confidence interval, 2.8-5.9; P<0.001) and presence of any tube complications (1.55; 1.0-2.3; P=0.03). Small-bore catheters (<14 French) were used in 12 (1%) of the episodes only. Tube complications were encountered in 214 (24%) episodes. Notwithstanding recommendations from international guidelines, simple aspiration and intercostal tube drainage with small-bore catheters were not commonly employed in the management of hospitalised patients with the various types of pneumothoraces in Hong Kong.
    Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine 12/2009; 15(6):427-33.
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    ABSTRACT: Lymphoepithelioma-like carcinoma (LELC) of lung has previously demonstrated good clinical response to 5-fluorouracil containing chemotherapy regimen, similar to the observation in undifferentiated nasopharyngeal carcinoma. Capecitabine, which is converted into active 5-fluorouracil within tumor cells, has been found effective in colorectal, breast, and recently nasopharyngeal carcinomas. We report our experience in five patients with advanced or metastatic LELC of lung who were treated with single agent capecitabine as salvage chemotherapy. The finding of disease control in three of five patients, especially with exceptionally durable stable disease (14.8 months) in one patient, suggests the potential clinical activity of capecitabine in LELC of lung. Future studies on capecitabine-containing chemotherapy regimens in LELC of lung are warranted.
    Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer 10/2009; 4(9):1174-7. · 4.55 Impact Factor
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    ABSTRACT: Chemotherapy is the mainstay treatment for advanced non-small cell lung cancer (NSCLC). Gefitinib, an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), has been recently shown to be effective as a first-line treatment in Asian patients with advanced NSCLC, especially for those with favourable clinical features such as female, non-smoker and adenocarcinoma. However, resistance to gefitinib ensues invariably and there is little evidence as for the effectiveness of subsequent salvage treatment. The purpose of this study is to evaluate the efficacy of erlotinib, another EGFR-TKI, after failed first-line use of gefitinib. Retrospective review of NSCLC patients with favourable clinical features who received gefitinib as first-line treatment and subsequent salvage treatment with erlotinib. A total of 21 patients with NSCLC were included in the study. Among them, 18 (85.7%) patients had disease control with gefitinib and 12 (57.1%) patients with salvage erlotinib. There was an association between the disease control with gefitinib and erlotinib (p = 0.031). The disease control rate of erlotinib was independent of the chemotherapy use between the two EGFR-TKIs. For NSCLC patients with favourable clinical features, erlotinib was effective in those who had prior disease control with first-line gefitinib.
    Cancer Chemotherapy and Pharmacology 09/2009; 65(6):1023-8. · 2.80 Impact Factor
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    ABSTRACT: This study investigated the roles of different potential pathophysiological mechanisms in the determination of blood pressure in relation to obstructive sleep apnea. The study was designed as a cross-sectional study. Consecutive healthy male subjects who were to undergo polysomnography were recruited. Demographic and anthropometric data were collected. Blood pressure measurements were taken in the evening before sleep and the next morning on waking. Overnight urinary samples for catecholamines and fasting blood for cortisol, insulin, glucose, and lipids were taken. Ninety-four men were analyzed, with a mean age of 43.7 +/- 9.3 years and mean apnea-hypopnea index (AHI) of 27.5 +/- 26.2 events/h. Sixty-nine patients (73%) had obstructive sleep apnea (AHI >or= 5). Urinary catecholamines were positively correlated with severity of sleep apnea, independent of obesity. Blood pressure measurements correlated with age, obesity, severity of sleep apnea, and urinary catecholamines. Regression analysis showed that sleep indices and urinary catecholamines were independent determinants of morning systolic and diastolic blood pressure, respectively, while total cholesterol and waist circumference were respective additional factors. Urinary catecholamines and waist circumference were determinants of evening blood pressure, with morning cortisol being an additional determinant for diastolic blood pressure. Obstructive sleep apnea and related sympathetic activity contributed significantly to the determination of daytime blood pressure in overweight middle-aged men without overt cardiometabolic diseases, and other contributing factors include abdominal obesity, total cholesterol, and cortisol levels.
    Beiträge zur Klinik der Tuberkulose 08/2009; 187(5):291-8. · 2.06 Impact Factor
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    ABSTRACT: The effects of treatment of obstructive sleep apnoea (OSA) on glucose metabolism have been investigated previously with conflicting results. This study evaluated the impact of nasal continuous positive airway pressure (nCPAP) treatment of OSA on insulin sensitivity. Males with moderate/severe OSA and no significant comorbidity were randomised to a therapeutic or sham nCPAP treatment group for 1 week and then reassessed. Those who received therapeutic nCPAP were further evaluated at 12 weeks. Insulin sensitivity (K(itt)) was estimated by the short insulin tolerance test. Other evaluations included blood pressure, metabolic profile, urinary catecholamines and intra-abdominal fat. In total, 61 Chinese subjects were randomised. 31 subjects receiving therapeutic nCPAP showed an increase in K(itt) (6.6+/-2.9 to 7.6+/-3.2 % x min(-1); p = 0.017), while the 30 patients on sham CPAP had no significant change, and the changes in K(itt) were different between the two groups (p = 0.022). At 12 weeks, improvement in K(itt) was seen in 20 subjects with BMI >or=25 kg x m(-2) (median (interquartile range) 28.3 (26.6-31.5); p = 0.044), but not in the nine subjects with BMI<25 kg x m(-2), or the entire group. The findings indicate that therapeutic nCPAP treatment of OSA for 1 week improved insulin sensitivity in nondiabetic males, and the improvement appeared to be maintained after 12 weeks of treatment in those with moderate obesity.
    European Respiratory Journal 07/2009; 35(1):138-45. · 6.36 Impact Factor
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    ABSTRACT: Obstructive sleep apnoea (OSA) is associated with insulin resistance and metabolic syndrome. There is evidence that adipocyte-fatty acid binding protein (A-FABP) may be involved in the development of cardiometabolic dysfunction. The present authors hypothesise that A-FABP is upregulated in OSA. A total of 124 males without hypertension, diabetes mellitus, hyperlipidaemia or cardiovascular disease were recruited and underwent polysomnography. Serum A-FABP levels showed significant positive correlations with duration of oxygen desaturation and minimal oxygen saturation, fasting insulin and insulin resistance index by homeostasis model assessment. When subjects were divided into tertiles according to apnoea/hypopnoea index (AHI), serum A-FABP levels were significantly higher in the group with AHI >/=34.4 events.h(-1) than the groups with AHI 13.2-34.4 events.h(-1) or with AHI <13.2 events.h(-1). Serum A-FABP levels were significantly higher in the AHI >/=34.4 group than obesity-matched subjects with AHI <34.4 events.h(-1). Serum adipocyte-fatty acid binding protein levels correlated with obstructive sleep apnoea and insulin resistance, independently of obesity, and were significantly higher in severe obstructive sleep apnoea. Adipocyte-fatty acid binding protein may play a role in obstructive sleep apnoea and metabolic dysfunction.
    European Respiratory Journal 02/2009; 33(2):346-51. · 6.36 Impact Factor
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    ABSTRACT: Among peritoneal dialysis (PD) patients, nocturnal PD (NPD) is known to improve sleep apnea compared with continuous ambulatory peritoneal dialysis (CAPD), but the contributing factors are unclear. Thirty-eight incident ESRD patients underwent overnight polysomnography (PSG) during NPD and CAPD. Bioelectrical impedance analysis, magnetic resonance imaging of the upper airway, and urea kinetics (Kt/V) during sleep were measured on both occasions. The prevalence of severe sleep apnea (apnea-hypopnea index, AHI > or = 15/h) was 21.1% during NPD, and 42.1% during CAPD. Mean AHI increased from 9.6 +/- 2.7/h during NPD to 21.5 +/- 4.2/h during CAPD. Both obstructive and central apnea worsened after conversion to CAPD. NPD achieved greater reductions in total body water, hydration fraction, and net ultrafiltration than CAPD during sleep. Overnight peritoneal Kt/V and creatinine clearance were lower after conversion. Both peritoneal Kt/V and peritoneal creatinine clearance correlated with AHI, as did their changes after conversion. Volumetric magnetic resonance imaging revealed reduced pharyngeal volumes and cross-sectional area, and tongue enlargement after conversion. Improvement in sleep apnea during NPD versus CAPD is associated with better fluid and uremic clearance and reduced upper airway congestion during sleep.
    Clinical Journal of the American Society of Nephrology 01/2009; 4(2):410-8. · 5.07 Impact Factor
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    ABSTRACT: Recent studies have demonstrated that cardiac resynchronization therapy (CRT) reduces sleep apnea in heart failure (HF); however, the mechanism of benefit remains unclear. Overnight polysomnography (PSG) was performed in consecutive HF patients who were scheduled for CRT implant. Patients with sleep apnea defined by an apnea-hypopnea index (AHI) of >10/hour were recruited and underwent echocardiogram examination at baseline and 3 months after CRT. Among 37 HF patients screened, 20 patients (54%) had sleep apnea and 15 of them consented for the study. After 3 months of CRT, there was a significant improvement in New York Heart Association functional class (3.1+/-0.1 vs 2.1+/-0.1, P<0.01), quality-of-life (QoL) score (62.9+/-3.3 vs 56.1+/-4.5, P=0.02), left ventricular ejection fraction (LVEF, 28.8+/-2.5% vs 38.1+/-2.3%, P<0.01), and reduction in pulmonary artery systolic pressure (PASP, 41.0+/-2.7 vs 28.6+/-2.2 mmHg; P<0.01) compared with baseline. Repeated PSG after CRT demonstrated a reduction in the duration of arterial oxygen desaturation<or=95% (251.2+/-36.7 vs 141.0+/-37.1 minutes), AHI (27.5+/-4.7 vs 18.1+/-3.0, P=0.05), and number of central sleep apnea (CSA) (7.8+/-2.6 vs 3.0+/-1.3/hour, P=0.03), but not number of obstructive sleep apnea (OSA, 8.6+/-3.3 vs 7.2+/-2.3/hour, P=0.65) compared to baseline. Percentage change in PASP was significantly correlated with percentage changes in LVEF (r=-0.57, P=0.04), AHI (r=0.5, P=0.05), and number of CSA episodes (r=0.55, P=0.02). The results demonstrated that CRT significantly reduces CSA in patients with HF. Importantly, we have noted a decrement of PASP correlated to drop in CSA which maybe one of the mechanisms explaining this observation. Future studies are required to confirm our finding and elucidate other possible mechanisms in this regard.
    Pacing and Clinical Electrophysiology 01/2009; 31(12):1522-7. · 1.75 Impact Factor
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    ABSTRACT: Both asthma and gastroesophageal reflux disease (GERD) are common, often coexist, and have significant impact on a patient's quality of life. Our aim was to determine the prevalence of GERD in asthmatic patients at a major hospital in Hong Kong, and to examine the impact of GERD and its association with asthma control. Patients with asthma who attended the respiratory clinic at Queen Mary Hospital, Hong Kong, were recruited. Demographic data were collected, and a validated Chinese GERD questionnaire was used. The Medical Outcomes Study 36-item short form (SF-36) was used to assess quality of life, and the Hospital Anxiety and Depression Scale (HADS) was used to assess psychological status. Asthma control was assessed by the asthma control test. A total of 218 patients were recruited; 40.4% of asthmatic patients (88 patients) had GERD, as defined by the GERD questionnaire. Compared with those patients without GERD, those with GERD had significantly worse asthma control (p = 0.022), worse quality of life in all domains of the SF-36 (all p < 0.01), and more anxiety (6.82 vs 4.90, respectively; p < 0.001) and depression (6.09 vs 4.05, respectively; p < 0.001) as reflected by HADSs. A significant proportion of asthmatic patients in Hong Kong have GERD, and this is associated with poorer asthmatic control, quality of life, and psychological status.
    Chest 01/2009; 135(5):1181-5. · 5.85 Impact Factor
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    ABSTRACT: The prognosis of early stage lung cancer was superior to that of late stages. We hypothesize that by using sputum cytology as the first screening method followed by autofluorescence bronchoscopy could detect early stage lung cancer in the central airway. During 18-month recruitment period, subjects at high risk for lung cancer (ever smoker accumulated more than 20 pack-year and above 40 years) followed up at Chest Clinics were invited to submit sputum for cytological examination. Subjects with sputum atypia were invited to have bronchoscopy, and CT thorax. After a mean follow-up of 39+/-14 months, the characteristics of lung cancers detected in the group with sputum atypia and the group with normal sputum at baseline were assessed. 181 subjects submitted sputum and primary lung cancer were diagnosed in 13. 46.2% of the lung cancers were in early stages. Bronchoscopy were performed in 85, and seven were confirmed to have lung cancer (six were in early stages). 81 had CT done and 92.6% had radiological abnormalities, though three lung cancers (all stage 0) were missed by CT. Five more primary lung cancers were diagnosed during the follow-up period: one in sputum atypia group and the other four (three were advanced adenocarcinoma) in normal sputum group. The overall sensitivity of sputum cytology in detecting lung cancer was 71.4% for all histology and 100% for squamous cell lung cancer. Sputum cytology examination followed by bronchoscopy was a practical way of detecting early stage lung cancer in central airway.
    Lung cancer (Amsterdam, Netherlands) 12/2008; 64(3):289-94. · 3.14 Impact Factor

Publication Stats

2k Citations
327.78 Total Impact Points

Institutions

  • 1998–2012
    • The University of Hong Kong
      • • Department of Medicine
      • • Department of Diagnostic Radiology
      Hong Kong, Hong Kong
  • 2011
    • Centro Hospitalar Conde S. Januário
      Macao, Macau, Macao
  • 2009–2011
    • Queen Elizabeth Hospital
      Hong Kong, Hong Kong
  • 2004–2011
    • Queen Mary Hospital
      Hong Kong, Hong Kong
  • 2005
    • Vancouver General Hospital
      Vancouver, British Columbia, Canada