Electromagnetic navigation bronchoscopy: the initial experience in Hong Kong.

BACKGROUND: Pulmonary nodules (PNs) are increasingly detected by thoracic computed tomography (CT). Traditional diagnostic modalities have their drawbacks. Electromagnetic navigation bronchoscopy (ENB) is gaining popularity in diagnosing small PNs. This study describes the diagnostic yield and complication rate of ENB in diagnosing PNs in which other diagnostic methods are considered to have low yield. METHODS: This is a retrospective study of the diagnostic yield and complication rate of ENB performed in the United Christian Hospital, Hong Kong, from April 2015 to June 2016. If a histological diagnosis was deemed necessary and flexible bronchoscopy (FB) was the preferred modality, patients were offered ENB if they have failed a conventional FB with fluoroscopy and radial endobronchoscopic ultrasonography (R-EBUS), or were perceived to have low yield because of the size or position of the PN. RESULTS: During the study period, 99 patients received ENB. An overall of 87 patients had non-resolved CT lesions and had specific pathologies identified (87.9%). The total number of malignant PNs was 67 (67.7%) in the entire cohort and tuberculosis (TB) accounted for 14 PNs (14.1%). The overall accuracy by ENB was 71.7%, sensitivity 67.8%, specificity 100% and negative predictive value 30%. Complications occurred in 3 patients: 1 pneumothorax (1.0%), 1 post-transbronchial biopsy (TBBx) bleeding (1.0%), 1 respiratory failure (1.0%). No patient died as a result of ENB or its complications. CONCLUSIONS: For PNs not accessible by conventional FB/R-EBUS, ENB provides good diagnostic yield with low complication rate. It is a useful armamentarium to respiratory physicians and thoracic surgeons.

Electromagnetic navigation bronchoscopy under intravenous sedation-tips and tricks.

Electromagnetic navigation bronchoscopy (ENB) is gaining acceptance and popularity amongst bronchoscopists as one of the tools to diagnose pulmonary nodules (PNs). Although the majority of ENBs in earlier studies were performed under general anaesthesia (GA), later reports suggest that the diagnostic yield of ENB under intravenous sedation (IVS) was comparable, and was time saving. ENB under IVS may potentially improve access of the techniques to practitioners and patients. However, it is technically challenging when compared to its performance under GA. This article reviews the techniques required for ENB under IVS to maximize its diagnostic yield and safety.

Delirium is a Strong Predictor of Mortality in Patients Receiving Non-invasive Positive Pressure Ventilation.

PURPOSE: Non-invasive positive pressure ventilation (NIPPV) has gained popularity over the years in the treatment of acute respiratory failure (ARF). Preliminary evidence suggests that delirium is an important factor contributing to NIPPV failure and death. This study was conducted to evaluate delirium and other associated factors of deaths in patients with ARF requiring the use of NIPPV. METHODS: A prospective observational study was conducted in a specialised NIPPV unit. Consecutive patients admitted for ARF requiring NIPPV were assessed by a psychiatrist for presence of delirium using the Diagnostic and Statistical Manual Version IV (DSM-IV). APACHE II score, co-morbidities-, and lung function were also assessed. Patients were followed until their deaths for a minimum of 1 year. Univariate and multivariate Cox's regression analyses were performed to explore predictive factors for death. RESULTS: A total of 153 subjects were recruited, 49 (32.0 %) of whom had delirium. On univariate analysis, higher APACHE II score, lower BMI, presence of delirium, higher Charlson's co-morbidity index but not FEV1 were associated with earlier death. On multivariate analysis, delirium (HR 4.4; 95 % CI 2.6-7.4; p < 0.001) and lower BMI (HR 0.92; 95 % CI 0.86-0.98; p = 0.013) were independently associated with earlier death within 1 year. CONCLUSIONS: There is a high prevalence of delirium in patients requiring NIPPV. The presence of delirium is a strong predictor of mortality. There is strong need to identify and manage these high-risk patients to improve their mortality. The collaboration between psychiatrists and physicians should be strengthened.

Evaluation of Pulmonary Nodules: Clinical Practice Consensus Guidelines for Asia.

BACKGROUND: American College of Chest Physicians (CHEST) clinical practice guidelines on the evaluation of pulmonary nodules may have low adoption among clinicians in Asian countries. Unique patient characteristics of Asian patients affect the diagnostic evaluation of pulmonary nodules. The objective of these clinical practice guidelines was to adapt those of CHEST to provide consensus-based recommendations relevant to practitioners in Asia. METHODS: A modified ADAPTE process was used by a multidisciplinary group of pulmonologists and thoracic surgeons in Asia. An initial panel meeting analyzed all CHEST recommendations to achieve consensus on recommendations and identify areas that required further investigation before consensus could be achieved. Revised recommendations were circulated to panel members for iterative review and redrafting to develop the final guidelines. RESULTS: Evaluation of pulmonary nodules in Asia broadly follows those of the CHEST guidelines with important caveats. Practitioners should be aware of the risk of lung cancer caused by high levels of indoor and outdoor air pollution, as well as the high incidence of adenocarcinoma in female nonsmokers. Furthermore, the high prevalence of granulomatous disease and other infectious causes of pulmonary nodules need to be considered. Therefore, diagnostic risk calculators developed in non-Asian patients may not be applicable. Overall, longer surveillance of nodules than those recommended by CHEST should be considered. CONCLUSIONS: TB in Asia favors lesser reliance on PET scanning and greater use of nonsurgical biopsy over surgical diagnosis or surveillance. Practitioners in Asia are encouraged to use these adapted consensus guidelines to facilitate consistent evaluation of pulmonary nodules.

Differences in baseline factors and survival between normocapnia, compensated respiratory acidosis and decompensated respiratory acidosis in COPD exacerbation: A pilot study.

BACKGROUND AND OBJECTIVE: Patients with chronic obstructive pulmonary disease (COPD) experiencing acute exacerbation (AE-COPD) with decompensated respiratory acidosis are known to have poor outcomes in terms of recurrent respiratory failure and death. However, the outcomes of AE-COPD patients with compensated respiratory acidosis are not known. METHODS: We performed a 1-year prospective, single-centre, cohort study in patients surviving the index admission for AE-COPD to compare baseline factors between groups with normocapnia, compensated respiratory acidosis and decompensated respiratory acidosis. Survival analysis was done to examine time to readmissions, life-threatening events and death. RESULTS: A total of 250 patients fulfilling the inclusion and exclusion criteria were recruited and 245 patients were analysed. Compared with normocapnia, both compensated and decompensated respiratory acidosis are associated with lower FEV1 % (P < 0.001), higher GOLD stage (P = 0.003, <0.001) and higher BODE index (P = 0.038, 0.001) and a shorter time to life-threatening events (P < 0.001). Comparing compensated and decompensated respiratory acidosis, there was no difference in FEV1 (% predicted) (P = 0.15), GOLD stage (P = 0.091), BODE index (P = 0.158) or time to life-threatening events (P = 0.301). High PaCO2 level (P = 0.002) and previous use of non-invasive ventilation (NIV) in acute setting (P < 0.001) are predictive factors of future life-threatening events by multivariate analysis. CONCLUSIONS: Compared with normocapnia, both compensated and decompensated respiratory acidosis are associated with poorer lung function and higher risk of future life-threatening events. High PaCO2 level and past history of NIV use in acute settings were predictive factors for future life-threatening events. Compensated respiratory acidosis warrants special attention and optimization of medical therapy as it poses risk of life-threatening events.

The effect of free-standing GaN substrate on carrier localization in ultraviolet InGaN light-emitting diodes.

In this study, we have grown 380-nm ultraviolet light-emitting diodes (UV-LEDs) based on InGaN/AlInGaN multiple quantum well (MQW) structures on free-standing GaN (FS-GaN) substrate by atmospheric pressure metal-organic chemical vapor deposition (AP-MOCVD), and investigated the relationship between carrier localization degree and FS-GaN. The micro-Raman shift peak mapping image shows low standard deviation (STD), indicating that the UV-LED epi-wafer of low curvature and MQWs of weak quantum-confined Stark effect (QCSE) were grown. High-resolution X-ray diffraction (HRXRD) analyses demonstrated high-order satellite peaks and clear fringes between them for the UV-LEDs grown on the FS-GaN substrate, from which the interface roughness (IRN) was estimated. The temperature-dependent photoluminescence (PL) measurement confirmed that the UV-LEDs grown on the FS-GaN substrate exhibited better carrier confinement. Besides, the high-resolution transmission electron microscopy (HRTEM) and energy-dispersive spectrometer (EDS) mapping images verified that the UV-LEDs on FS-GaN have fairly uniform distribution of indium and more ordered InGaN/AlInGaN MQW structure. Clearly, the FS-GaN can not only improve the light output power but also reduce the efficiency droop phenomenon at high injection current. Based on the results mentioned above, the FS-GaN can offer UV-LEDs based on InGaN/AlInGaN MQW structures with benefits, such as high crystal quality and small carrier localization degree, compared with the UV-LEDs on sapphire.

A pilot randomized study comparing two methods of non-invasive ventilation withdrawal after acute respiratory failure in chronic obstructive pulmonary disease.

BACKGROUND AND OBJECTIVE: Patients 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. RESULTS: Sixty 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.

Compliance with home non-invasive ventilation.

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%.

Daptomycin as successful treatment for a refractory case of prosthetic valve endocarditis because of methicillin-sensitive Staphylococcus aureus.

We report on an intravenous drug user who presented with methicillin-sensitive Staphylococcus aureus bacteremia and endocarditis of a prosthetic tricuspid valve, with a 4-cm vegetation refractory to standard antibiotic treatment. The patient responded to intravenous daptomycin therapy clinically and microbiologically, despite an absence of surgical intervention.

Risk factors for chronic post-traumatic stress disorder (PTSD) in SARS survivors.

BACKGROUND: Post-traumatic stress disorder (PTSD) is one of the most prevalent long-term psychiatric diagnoses among survivors of severe acute respiratory syndrome (SARS). OBJECTIVES: The objective of this study was to identify the predictors of chronic PTSD in SARS survivors. DESIGN: 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. RESULTS: 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. CONCLUSION: 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.

Prevention of acute myocardial infarction and stroke among elderly persons by dual pneumococcal and influenza vaccination: a prospective cohort study.

BACKGROUND: Despite World Health Organization recommendations, the rate of 23-valent pneumococcal (PPV) and influenza (TIV) vaccination among elderly persons in Hong Kong, China, is exceptionally low because of doubts about effectiveness of vaccination. The efficacy of dual vaccination remains unknown. METHODS: From 3 December 2007 to 30 June 2008, we conducted a prospective cohort study by recruiting outpatients aged ≥65 years with chronic illness to participate in a PPV and TIV vaccination program. All were observed until 31 March 2009. The outcome of subjects, including the rates of death, hospitalization, pneumonia, ischemic stroke, acute myocardial infarction, and coronary and intensive care admissions, were determined. RESULTS: Of the 36,636 subjects recruited, 7292 received both PPV and TIV, 2076 received TIV vaccine alone, 1875 received PPV alone, and 25,393 were unvaccinated, with a duration of follow-up of 45,834 person-years. Baseline characteristics were well matched between the groups, except that there were fewer male patients in the PPV and TIV group and fewer cases of comorbid chronic obstructive pulmonary disease among unvaccinated persons. At week 64 from commencement of the study, dual-vaccinees experienced fewer deaths (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.55-0.77]; P<.001) and fewer cases of pneumonia (HR, 0.57; 95% CI, 0.51-0.64; P<.001), ischemic stroke (HR, 0.67; 95% CI, 0.54-0.83; P<.001), and acute myocardial infarction (HR, 0.52; 95% CI, 0.38-0.71; P<.001), compared with unvaccinated subjects. Dual vaccination resulted in fewer coronary (HR, 0.59; 95% CI, 0.44-0.79; P<.001) and intensive care admissions (HR, 0.45; 95% CI, 0.22-0.94; P=.03), compared with among unvaccinated subjects. CONCLUSIONS: Dual vaccination with PPV and TIV is effective in protecting elderly persons with chronic illness from developing complications from respiratory, cardiovascular, and cerebrovascular diseases, thereby reducing hospitalization, coronary or intensive care admissions, and death.

CD209 (DC-SIGN) -336A>G promoter polymorphism and severe acute respiratory syndrome in Hong Kong Chinese.

CD209 (DC-SIGN) is an important C-type lectin which acts a receptor of many pathogens. The single nucleotide polymorphism (SNP) -336A>G in the CD209 promoter has been demonstrated to regulate promoter activity and to be associated with several important infectious diseases, such as human immunodeficiency virus-1 (HIV-1), Mycobacterium tuberculosis, and Dengue fever. CD209 facilitates severe acute respiratory syndrome (SARS)-coronavirus spike protein-bearing pseudotype driven infection of permissive cells in vitro. In keeping with previously published findings, our in vitro studies confirmed that this SNP modulates gene promoter activity. Genetic association analysis of this SNP with clinico-pathologic outcomes in 824 serologic confirmed SARS patients showed that the -336AG/GG genotype SARS patients was associated with lower standardized lactate-dehydrogenase (LDH) levels compared with the -336AA patients (p = 0.014, odds ratio = 0.40). High LDH levels are known to be an independent predictor for poor clinical outcome, probably related to tissue destruction from immune hyperactivity. Hence, SARS patients with the CD209 -336 AA genotype carry a 60% chance of having a poorer prognosis. This association is in keeping with the role of CD209 in modulating immune response to viral infection. The relevance of these findings for other infectious diseases and inflammatory conditions would be worth investigating.

Sleep apnea is a novel risk predictor of cardiovascular morbidity and death in patients receiving peritoneal dialysis.

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.

Antibiotic resistance in community-acquired pneumonia caused by Streptococcus pneumoniae, methicillin-resistant Staphylococcus aureus, and Acinetobacter baumannii.

Antimicrobial therapy is the mainstay of management for community-acquired pneumonia (CAP). Accordingly, the choices of treatment are influenced by the likely etiologies, local resistance patterns of the pathogens, as well as patient factors. As the leading cause of acute CAP, the susceptibility patterns of Streptococcus pneumoniae have greatly influenced antimicrobial agents and dosage recommended for empirical treatment of this condition. The worldwide emergence of community-acquired methicillin-resistant Staphylococcus aureus has also led to discussion of this pathogen in recent revisions of the international CAP guidelines. This pathogen is important because of its resistance to antibiotics commonly recommended for the empirical treatment of CAP and the association with a rapidly fatal form of pneumonia characterized by tissue necrosis, pulmonary hemorrhage, and rapid progression to respiratory failure. In tropical regions of Australia and Asia, CAP due to Acinetobacter baumannii is also increasingly recognized. This review discusses their recent epidemiology, microbiology, clinical features, and treatment of CAP caused by these antimicrobial-resistant pathogens.

Long-term psychiatric morbidities among SARS survivors.

OBJECTIVE: 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. METHOD: 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. RESULTS: 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. CONCLUSION: 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.

The burden of lung disease in Hong Kong: a report from the Hong Kong Thoracic Society.

BACKGROUND AND OBJECTIVE: The burden of lung disease in Hong Kong is not known. This study determined the mortality and hospitalization rates of respiratory diseases in Hong Kong in 2005, their trend in the past decade and their incidence/prevalence. METHODS: Mortality data were obtained from the Department of Health and hospitalization data from the Hospital Authority, Hong Kong. Incidence/prevalence data were obtained from local registries or local studies. Trends of mortality and hospitalization rates of various respiratory diseases from 1997 and 2005 were calculated after age standardization and were tested for significance using negative binomial regression analysis. Age standardized mortality rates in Hong Kong were compared with those of the UK and globally. RESULTS: Respiratory disease was the most common cause of mortality and hospitalization in Hong Kong in 2005. Globally and in the UK, cardiovascular disease ranked first in mortality. Respiratory infections ranked first in respiratory mortality, followed by respiratory tract cancer and chronic obstructive lung disease. Respiratory infections also ranked first followed by chronic obstructive lung disease in the utilization of respiratory inpatient bed-days. While mortality rates from all respiratory diseases decreased in the past decade, hospitalization rates remained unchanged. Unlike other respiratory diseases, mortality from respiratory infections have increased since 2001. Smoking is the most important risk factor in non-communicable respiratory diseases. CONCLUSIONS: Respiratory disease is responsible for the highest health-care burden locally. Increased efforts in improving management and prevention of these diseases, including tobacco control, improving air quality and vaccination against influenza and pneumococci, are necessary.

Association of ICAM3 genetic variant with severe acute respiratory syndrome.

Genetic polymorphisms have been demonstrated to be associated with vulnerability to human infection. ICAM3, an intercellular adhesion molecule important for T cell activation, and FCER2 (CD23), an immune response gene, both located on chromosome 19p13.3, were investigated for host genetic susceptibility and association with clinical outcome. A case-control study based on 817 patients with confirmed severe acute respiratory syndrome (SARS), 307 health care worker control subjects, 290 outpatient control subjects, and 309 household control subjects unaffected by SARS from Hong Kong was conducted to test for genetic association. No significant association to susceptibility to SARS infection caused by the novel coronavirus (SARS-CoV) was found for the FCER2 and the ICAM3 single nucleotide polymorphisms. However, patients with SARS homozygous for ICAM3 Gly143 showed significant association with higher lactate dehydrogenase levels (P=.0067; odds ratio [OR], 4.31 [95% confidence interval {CI}, 1.37-13.56]) and lower total white blood cell counts (P=.022; OR, 0.30 [95% CI, 0.10-0.89]) on admission. These findings support the role of ICAM3 in the immunopathogenesis of SARS.