V L Chan

Lands Department of The Government of the Hong Kong Special Administrative Region, Hong Kong, Hong Kong

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Publications (18)78.33 Total impact

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    ABSTRACT: Background and objectivePatients with chronic obstructive pulmonary disease (COPD) presenting with acute hypercapnic respiratory failure (AHcRF) benefit from non-invasive ventilation (NIV). The best way to withdraw NIV is not known, and we conducted a pilot study comparing stepwise versus immediate withdrawal of NIV in these patients. Methods This was a prospective, single-centre, open-labelled randomized study comparing stepwise versus immediate withdrawal of NIV in patients with COPD exacerbation recovering from AHcRF. The primary end-point was the success rate of NIV withdrawal, defined as no restarting of NIV from randomization to 48 h after complete withdrawal of NIV. ResultsSixty patients were randomized, 35 patients to stepwise withdrawal and 25 patients to immediate withdrawal. The two study arms were clinically comparable. There was no statistically significant difference in the success rate, with NIV successfully stopped in 74.3% and 56% in the stepwise and immediate withdrawal groups, respectively (P = 0.139). Conclusions We could not show any benefits for either strategy to withdraw NIV. The study may have been underpowered to detect differences, and larger prospective studies are required.
    Respirology 07/2013; 18(5). · 2.78 Impact Factor
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    Suet-Lai Cheng, Veronica L Chan, Chung-Ming Chu
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    ABSTRACT: Home non-invasive ventilation (NIV) is being increasingly employed to treat chronic hypercapnic respiratory failure. However, there is little data on compliance with home NIV. Sixty-five patients, aged 72.6 ± 9.4 years, who were using home NIV were administered a questionnaire on symptomatology and adverse effects associated with home NIV. Mean daily use of home NIV was 7.3 ± 2.9 h/day, and the median percentage of days on which home NIV was used for ≥4 h/day was 96.7%.
    Respirology 03/2012; 17(4):735-6. · 2.78 Impact Factor
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    ABSTRACT: Patients with chronic obstructive pulmonary disease (COPD) who survive an episode of acute hypercapnic respiratory failure (AHRF) after treatment with non-invasive ventilation (NIV) have a high risk of recurrent AHRF. We hypothesised that continuation of NIV at home in these patients would reduce the likelihood of recurrent AHRF. A pilot prospective randomised controlled study was designed to compare continuation of active home NIV and continuous positive airway pressure (CPAP) 5 cm H(2)O (controls) in COPD patients who had survived an episode of AHRF treated with acute NIV. Patients with significant obstructive sleep apnoea, non-COPD causes of AHRF, adverse psychosocial circumstances and serious comorbidities were excluded. The primary end-point was recurrent AHRF requiring acute NIV, intubation or resulting in death in the first year. Twenty-three patients were randomised to receive home NIV and 24 received CPAP. There was no significant difference in the baseline characteristics between the two study groups. The proportion of patients developing recurrent AHRF in the NIV and the CPAP groups was 38.5% vs. 60.2% at 1 year (P = 0.039). Four and eight patients, respectively, were withdrawn from the CPAP and NIV groups before the end of the pre-defined study duration. In selected COPD patients with AHRF treated with acute NIV, continuation with home NIV is associated with a lower risk of recurrent severe COPD exacerbation with AHRF when compared with CPAP.
    The International Journal of Tuberculosis and Lung Disease 05/2010; 14(5):642-9. · 2.76 Impact Factor
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    ABSTRACT: Post-traumatic stress disorder (PTSD) is one of the most prevalent long-term psychiatric diagnoses among survivors of severe acute respiratory syndrome (SARS). The objective of this study was to identify the predictors of chronic PTSD in SARS survivors. PTSD at 30 months after the SARS outbreak was assessed by the Structured Clinical Interview for the DSM-IV. Survivors' demographic data, medical information and psychosocial variables were collected for risk factor analysis. Multivariate logistic regression analysis showed that female gender as well as the presence of chronic medical illnesses diagnosed before the onset of SARS and avascular necrosis were independent predictors of PTSD at 30 months post-SARS. Associated factors included higher-chance external locus of control, higher functional disability and higher average pain intensity. The study of PTSD at 30 months post-SARS showed that the predictive value of acute medical variables may fade out. Our findings do not support some prior hypotheses that the use of high dose corticosteroids is protective against the development of PTSD. On the contrary, the adversity both before and after the SARS outbreak may be more important in hindering recovery from PTSD. The risk factor analysis can not only improve the detection of hidden psychiatric complications but also provide insight for the possible model of care delivery for the SARS survivors. With the complex interaction of the biopsychosocial challenges of SARS, an integrated multidisciplinary clinic setting may be a superior approach in the long-term management of complicated PTSD cases.
    General hospital psychiatry 01/2010; 32(6):590-8. · 2.67 Impact Factor
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    ABSTRACT: Tertiary referral centres. To provide comprehensive updates on the aetiologies, angiographic findings and outcomes of bronchial artery embolisation (BAE) for life-threatening haemoptysis in Hong Kong. Retrospective review of clinical records of consecutive patients presenting with life-threatening haemoptysis from 2000 to 2006. There were 3006 admissions due to haemoptysis involving 2260 patients during the study period; of these, 251 patients had life-threatening haemoptysis. Pulmonary tuberculosis (PTB) (active or inactive) and bronchiectasis were the main underlying causes. BAE was attempted in 167 patients. There was a high prevalence of bilateral bronchial arterial abnormalities (31.7%), presence of abnormal non-bronchial arteries (41.3%) and presence of broncho-pulmonary shunt (38.9%). BAE had a high immediate success rate of 95.7%, with a 5-year recurrence rate of 45.0%. Recurrent life-threatening haemoptysis was independently associated with past history of haemoptysis (P = 0.024), presence of broncho-pulmonary shunt (P = 0.013), and incomplete embolisation (P = 0.002). Complications were uncommon (<5%) and self-limiting. In Hong Kong, about one tenth of admissions due to haemoptysis were life-threatening. PTB and bronchiectasis were the major causes. Complications due to BAE were uncommon and self-limiting, with super-selective catheters.
    The International Journal of Tuberculosis and Lung Disease 09/2009; 13(9):1167-73. · 2.76 Impact Factor
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    ABSTRACT: Severe acute respiratory syndrome (SARS) was the first massive infectious disease outbreak of the 21st century. However, it is unlikely that this outbreak will be the last. This study aimed to evaluate the long-term psychiatric morbidities in survivors of SARS. This is a cohort study designed to investigate psychiatric complications among SARS survivors treated in the United Christian Hospital 30 months after the SARS outbreak. Psychiatric morbidities were assessed by the Structured Clinical Interview for DSM-IV, the Impact of Events Scale-Revised and the Hospital Anxiety and Depression Scale. Functional outcomes were assessed by the Medical Outcomes Study 36-Item Short-Form Health Survey. Ninety subjects were recruited, yielding a response rate of 96.8%. Post-SARS cumulative incidence of DSM-IV psychiatric disorders was 58.9%. Current prevalence for any psychiatric disorder at 30 months post-SARS was 33.3%. One-fourth of the patients had post-traumatic stress disorder (PTSD), and 15.6% had depressive disorders. The outbreak of SARS can be regarded as a mental health catastrophe. PTSD was the most prevalent long-term psychiatric condition, followed by depressive disorders. Our results highlight the need to enhance preparedness and competence of health care professionals in detecting and managing the psychological sequelae of future comparable infectious disease outbreaks.
    General hospital psychiatry 07/2009; 31(4):318-26. · 2.67 Impact Factor
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    K Y Tsang, W S Leung, Veronica L Chan, Alsa W L Lin, C M Chu
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    ABSTRACT: To describe the microbiological characteristics of a cohort of patients with complicated parapneumonic effusion and empyema thoracis, and to identify the potential risk factors for adverse outcomes, with particular reference to the choice of empirical antibiotics, intrapleural fibrinolytics, adherence to management guidelines, and input from pulmonologists. Retrospective review. Regional hospital, Hong Kong. All patients with a diagnosis of complicated parapneumonic effusion/empyema thoracis admitted between January 2003 and June 2005. Microbiological characteristics, mortality, and surgery-free survival. RESULTS. There were 63 patients, with a mean age of 64 (standard deviation, 16) years and a male-to-female ratio of 45:18. The pleural fluid culture positivity rate was 68%; Streptococcus milleri (19%), Bacteroides (14%), Klebsiella pneumoniae (12%), and Peptostreptococcus (7%) were the most common organisms. Thirteen (21%) patients died during their index admission. Use of intrapleural fibrinolytics according to the guideline was associated with survival (P=0.001) while discordant initial antibiotic use was associated with mortality (P=0.002). Discordant initial antibiotic use was also independently associated with reduced surgery-free survival (P<0.001). Subgroup analysis showed that early intrapleural fibrinolytic use (within 4 days of diagnosis) was associated with decreased mortality (P<0.001), increased surgery-free survival (P=0.005), and shorter hospital stay (P=0.039). Organisms identified from complicated parapneumonic effusion and empyema thoracis differ from those giving rise to community-acquired pneumonia. In these patients, adherence to guidelines, early concordant antibiotic treatment, intrapleural fibrinolytics, and input from a pulmonologist were associated with improved outcomes.
    Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine 07/2007; 13(3):178-86.
  • Chest 10/2006; 130(3):924-7. · 7.13 Impact Factor
  • Chest 03/2006; 129(2):488-92. · 7.13 Impact Factor
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    ABSTRACT: Severe acute respiratory syndrome (SARS) is a highly infectious respiratory infection with a high mortality. The duration of infectivity is unknown. The RT-PCR positivity for SARS-associated coronavirus (SARS-CoV) was followed in 45 virologically confirmed SARS patients. Serial RT-PCRs for SARS-CoV were performed in the nasopharyngeal aspirate, stool and urine of 45 SARS patients who survived until discharge. All patients had at least one site that was positive for SARS-CoV on presentation. Time to RT-PCR conversion was studied in all patients. There were 15 males (33.3%) and 30 females (66.7%), with a mean+/- SD age of 40.7+/-14.7 yrs. The median (range) time of RT-PCR conversion was 30 days (2-81). On discharge from the hospital, 18 (40%) remained RT-PCR positive in at least one site. For patients with positive RT-PCR on discharge, the median (range) time to RT-PCR conversion after discharge was 13 days (2-60). A significant proportion of severe acute respiratory syndrome patients remained RT-PCR positive for severe acute respiratory syndrome-associated coronavirus for a substantial duration after discharge. The clinical significance is unknown and this finding merits further study. It is prudent to advise patients to adhere to strict personal hygiene on discharge until RT-PCR becomes negative.
    European Respiratory Journal 02/2005; 25(1):12-4. · 6.36 Impact Factor
  • Hong Kong Journal of Nephrology 01/2005; 7(2).
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    ABSTRACT: Non-invasive ventilation (NIV) has been shown to reduce intubation and in-hospital mortality in patients with chronic obstructive pulmonary disease (COPD) and acute hypercapnic respiratory failure (AHRF). However, little information exists on the outcomes following discharge. A study was undertaken to examine the rates of readmission, recurrent AHRF, and death following discharge and the risk factors associated with them. A cohort of COPD patients with AHRF who survived after treatment with NIV in a respiratory high dependency unit was prospectively followed from July 2001 to October 2002. The times to readmission, first recurrent AHRF, and death were recorded and analysed against potential risk factors collected during the index admission. One hundred and ten patients (87 men) of mean (SD) age 73.2 (7.6) years survived AHRF after NIV during the study period. One year after discharge 79.9% had been readmitted, 63.3% had another life threatening event, and 49.1% had died. Survivors spent a median of 12% of the subsequent year in hospital. The number of days in hospital in the previous year (p = 0.016) and a low Katz score (p = 0.018) predicted early readmission; home oxygen use (p = 0.002), APACHE II score (p = 0.006), and a lower body mass index (p = 0.041) predicted early recurrent AHRF or death; the MRC dyspnoea score (p<0.001) predicted early death. COPD patients with AHRF who survive following treatment with NIV have a high risk of readmission and life threatening events. Further studies are urgently needed to devise strategies to reduce readmission and life threatening events in this group of patients.
    Thorax 12/2004; 59(12):1020-5. · 8.38 Impact Factor
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    ABSTRACT: Severe acute respiratory syndrome (SARS) is caused by a novel coronavirus. It may progress to respiratory failure, and a significant proportion of patients die. Preliminary data suggest that a high viral load of the SARS coronavirus is associated with adverse outcomes in the intensive care unit, but the relation of viral load to survival is unclear. We prospectively studied an inception cohort of 133 patients with virologically confirmed SARS who were admitted to 2 general acute care hospitals in Hong Kong from Mar. 24 to May 4, 2003. The patients were followed until death or for a minimum of 90 days. We used Cox proportional hazard modelling to analyze potential predictors of survival recorded at the time of presentation, including viral load from nasopharyngeal specimens (measured by quantitative reverse transcriptase polymerase chain reaction [PCR] of the SARS-associated coronavirus). Thirty-two patients (24.1%) met the criteria for acute respiratory distress syndrome, and 24 patients (18.0%) died. The following baseline factors were independently associated with worse survival: older age (61-80 years) (adjusted hazard ratio [HR] 5.24, 95% confidence interval [CI] 2.03-13.53), presence of an active comorbid condition (adjusted HR 3.36, 95% CI 1.44-7.82) and higher initial viral load of SARS coronavirus, according to quantitative PCR of nasopharyngeal specimens (adjusted HR 1.21 per log10 increase in number of RNA copies per millilitre, 95% CI 1.06-1.39). We found preliminary evidence that higher initial viral load is independently associated with worse prognosis in SARS. Mortality data for patients with SARS should be interpreted in light of age, comorbidity and viral load. These considerations will be important in future studies of SARS.
    Canadian Medical Association Journal 12/2004; 171(11):1349-52. · 6.47 Impact Factor
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    ABSTRACT: Spontaneous pneumomediastinum (SP) unrelated to assisted ventilation is a newly recognised complication of severe acute respiratory syndrome (SARS). The objective of the present study was to examine the incidence, risk factors and the outcomes of SP in a cohort of SARS victims from a community outbreak. Data were retrieved from a prospectively collected database of virologically confirmed SARS patients. One hundred and twelve cases were analysable, with 13 patients developing SP (11.6%) at a mean +/- SD of 19.6 +/- 4.6 days from symptom onset. Peak lactate dehydrogenase level was associated with the development of SP. SP was associated with increased intubation and a trend towards death. Drainage was required in five cases. For patients who survived, the SP and/or the associated pneumothoraces took a median of 28 days (interquartile range: 15-45 days) to resolve completely. In conclusion, spontaneous pneumomediastinum appeared to be a frequent complication of severe acute respiratory syndrome. Further research is needed to investigate its pathogenesis.
    European Respiratory Journal 07/2004; 23(6):802-4. · 6.36 Impact Factor
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    ABSTRACT: Old tuberculosis and bronchiectasis are the two most important causes of chronic structural changes of lungs in our locality. In the absence of radiologically visible mycetoma, the cause of hemoptysis in these two groups of patients is largely unknown. A 17-month prospective study was carried out to compare the prevalence of Aspergillus fumigatus and Aspergillus flavus antibodies in hemoptysis patients with old tuberculosis or bronchiectasis but no radiologically visible mycetoma (cases, n = 38), hemoptysis patients with other diagnosis (control group 1, n = 29), and patients with old tuberculosis or bronchiectasis but no hemoptysis (control group 2, n = 47) by a recently developed sensitive and specific A. fumigatus and A. flavus antibody assay. There were a significantly larger number of patients with antibody against A. fumigatus or A. flavus among the cases than among the patients in control groups 1 and 2 (P < 0.05 in both comparisons). Molds were not recovered from any of the patients. Among the 10 cases with Aspergillus antibody, eight and two had antibody against A. flavus and A. fumigatus, respectively. We conclude that there was an association between the presence of Aspergillus antibodies and hemoptysis in patients with old tuberculosis or bronchiectasis, suggesting that these patients probably had occult infections caused by the corresponding fungi. Development of serological tests against other Aspergillus species as well as other causes of mycetoma will probably increase the detection of occult mold infections in patients with existing parenchymal lung diseases, and treatment of fungal microinvasion may help to alleviate hemoptysis in these patients with bronchiectasis or old tuberculosis who have Aspergillus antibodies.
    Journal of Clinical Microbiology 03/2004; 42(2):665-9. · 4.07 Impact Factor
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    ABSTRACT: To determine the long-term outcome of noninvasive ventilation in chronic obstructive pulmonary disease patients who refused intubation for acute hypercapnic respiratory failure. Prospective, observational study. Noninvasive ventilation unit in an acute regional hospital in Hong Kong. The study recruited 37 chronic obstructive pulmonary disease patients who had the do-not-intubate code and developed acute hypercapnic respiratory failure. They were offered noninvasive ventilation, and their long-term outcomes were followed. Survival and event-free survival (an event is death or recurrent acute hypercapnic respiratory failure) were analyzed by survival analysis. Their disease profile and outcome were compared with another 43 chronic obstructive pulmonary disease patients without the do-not-intubate codes, who had acute hypercapnic respiratory failure and received noninvasive ventilation during the study period (usual care group). Patients in the do-not-intubate group were significantly older (p =.029), had worse dyspnea score (p <.001), worse Katz Activities of Daily Living score (p <.001), worse comorbidity score (p =.024), worse Acute Physiology and Chronic Health Evaluation II score (p =.032), lower hemoglobin (p =.001), and longer stay in the hospital during the past year (p =.001) than patients who received usual care. In the do-not-intubate group, the median survival was 179 days, and 1-yr actuarial survival was 29.7%; in the usual care group, the median survival was not reached during follow-up, and 1-yr actuarial survival was 65.1% (p <.0001). In the do-not-intubate group, the median event-free survival was 102 days, and 1-yr event-free survival was 16.2%; in the usual care group, median event-free survival was 292 days, and 1-yr event-free survival was 46.5% (p =.0004). A 1-yr survival of about 30% was recorded in chronic obstructive pulmonary disease patients with the do-not-intubate code who developed acute hypercapnic respiratory failure requiring noninvasive ventilation. The majority of survivors developed another life-threatening event in the following year. Information generated from this study is important to physicians and chronic obstructive pulmonary disease patients when they are considering using noninvasive ventilation as a last resort.
    Critical Care Medicine 02/2004; 32(2):372-7. · 6.12 Impact Factor
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    ABSTRACT: The aim of this study was to examine whether patients with newly diagnosed tuberculosis (TB) discharged to ambulatory treatment are at risk of unplanned readmission through the emergency department within 28 days of discharge, and the risk factors associated with such readmission. A cohort of 134 patients admitted to an acute medical department with TB, who were subsequently discharged to ambulatory treatment of TB, were studied by a retrospective record review for unplanned readmission in 28 days. Potential risk factors associated with the readmission were recorded during hospital stay and follow-up visits, including age, sex, length of stay, substance abuse, need of assistance in the activities of daily living (ADL), comorbidities, non-compliance, drug complications and use of non-standard drug regimen. Up to 20.1% of patients were readmitted. Factors independently associated with early unplanned readmission were need of assistance in ADL, drug complications, the need to use a non-standard drug regimen and more than three non-chest comorbidities. A significant readmission rate was found in these patients and potential risk factors were identified. Ambulatory treatment for TB may not be appropriate for selected patients. Local guidelines for the management of TB patients at high risk of readmission is needed.
    Respirology 07/2001; 6(2):145-9. · 2.78 Impact Factor
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    C M Chu, V L Chan
    Chest 12/1999; 116(5):1495-6. · 7.13 Impact Factor