Implementation of evidence on management of pleural diseases: insights from a territory-wide survey of clinicians in Hong Kong.

BACKGROUND: Major advances in management of common pleural diseases have taken place in the past decade. However, pleural diseases are often managed by physicians of diverse training background and research on implementation of new knowledge is scanty. We aim to evaluate the practice pattern in pleural medicine among physicians in Hong Kong, for identification of possible gaps for clinical service improvement. METHODS: The Hong Kong Thoracic Society undertook a cross-sectional questionnaire survey in 2019, targeting clinicians of various subspecialties in internal medicine and levels of experience (basic and higher trainees, specialists) from twelve regional hospitals of diverse service scopes throughout Hong Kong. Respondents were selected by non-probability quota sampling. The questionnaire tool consisted of 46 questions covering diagnostic and therapeutic aspects of common pleural diseases. The responses were anonymous, and analysed independently using SPSS statistics software. RESULTS: The survey collected 129 responses, 47(36%) were from clinicians specialized in respiratory medicine. Majority of the respondents (98%) managed pleural diseases, including performing pleural procedures in their practice. Fifty-five percent of all the respondents had not received any formal training in transthoracic ultrasonography. A significant proportion of clinicians were unaware of pleuroscopy for investigation of exudative pleural effusion, indwelling pleural catheter for recurrent malignant pleural effusion, and combined intra-pleural Alteplase plus DNase for treatment of pleural infection (30%, 15% and 70% of non-respiratory clinicians respectively). Significant heterogeneity was found in the management of pleural infection, malignant pleural effusion and pneumothorax among respiratory versus non-respiratory clinicians. Contributing factors to the observed heterogeneity included lack of awareness or training, limited accessibility of drugs, devices, or dedicated service support. CONCLUSION: Significant heterogeneity in management of pleural diseases was observed among medical clinicians in Hong Kong. Continuous medical education and training provision for both specialists and non-specialists has to be strengthened to enhance the implementation of advances, improve quality and equity of healthcare provision in pleural medicine.

Mesenteric fat thickness is associated with metabolic syndrome independently of Apnoea-Hypopnoea Index in subjects with obstructive sleep apnoea.

BACKGROUND AND OBJECTIVE: Mesenteric fat thickness (MFT) was associated with metabolic syndrome (MetS) and obstructive sleep apnoea (OSA) in separate studies. This study aimed to assess whether the association of MFT with MetS was independent of OSA in subjects with suspected OSA. METHODS: Two hundred forty-two subjects (men: 181; women: 61) with suspected OSA underwent ultrasound examinations for measurements of mesenteric, subcutaneous and preperitoneal fat thicknesses after overnight polysomnography. Anthropometric measurements and metabolic risk profile were assessed. RESULTS: Two hundred twenty-one (91%) subjects were confirmed to have OSA with Apnoea-Hypopnoea Index (AHI) >5/h. MFT had significant correlation (P < 0.01) with AHI and most MetS components. In partial correlation with adjustment for AHI, MFT had significant correlation (P < 0.01) with most MetS components including fasting plasma glucose (r = 0.25), triglycerides (r = 0.24), HDL cholesterol (r = -0.29) and waist circumference (r = 0.56). In multivariate logistic regression with adjustments for the confounding variables including AHI, MFT was the only variable independently associated with MetS, with the odds ratio of 5.48 (95% CI: 1.5-20.0) for every 1 cm increase of MFT. When the subjects were subdivided into obese (BMI ≥ 27.5 kg/m(2) ) and non-obese (BMI < 27.5 kg/m(2) ) groups, the positive association of MFT with MetS persisted in the non-obese group only, with the odds ratio of 22 (95% CI 2.8-174.1) for every 1 cm increase of MFT. The AHI had significant association with MetS in male subjects only. CONCLUSION: MFT, rather than AHI, is the major independent determinant of MetS in subjects with suspected OSA, particularly in non-obese subjects. See Editorial, page 408.

Mesenteric fat thickness is associated with increased risk of obstructive sleep apnoea.

BACKGROUND AND OBJECTIVE: Mesenteric fat is a type of intraperitoneal adipose tissue draining into portal circulation. The objective of this study was to investigate the relationships between mesenteric fat thickness and obstructive sleep apnoea (OSA) in patients with suspected OSA. METHODS: One hundred forty-nine subjects (men: 114; women: 35) with suspected OSA underwent ultrasound examinations of mesenteric, preperitoneal and subcutaneous fat thickness after overnight polysomnography. Body mass index (BMI) and neck circumference were recorded. RESULTS: The subjects with OSA (n = 130, apnoea/hypopnoea index (AHI) >5/h) had greater neck circumference, higher BMI, and greater mesenteric and preperitoneal fat thickness than those without OSA (n = 19, AHI ≤ 5/h). There was positive correlation of AHI with mesenteric (r = 0.43, P < 0.001) and preperitoneal fat thickness (r = 0.3, P < 0.001), whereas no significant association was observed between AHI and subcutaneous fat thickness (r = 0.09, P = 0.27). On multivariate logistic regression, after adjustments for gender, age, BMI, neck circumference, and preperitoneal and subcutaneous fat thickness, the mesenteric fat thickness had a positive association with the presence of moderate OSA and severe OSA, with odds ratios of 7.18 and 7.45 for every 1 cm increase in mesenteric fat thickness when AHI was defined as ≥15/h and AHI ≥ 30/h, respectively. CONCLUSIONS: Mesenteric fat thickness is associated with increased risk of OSA, independent of other abdominal fat thickness, BMI and neck circumference. Sonographic measurement is potentially a useful tool for further evaluating the complex association of visceral fat, metabolic syndrome and OSA.

Pneumomediastinum and subcutaneous emphysema complicating a patient with a lung abscess.

Pneumomediastinum and subcutaneous emphysema are conditions that carry significant morbidity. They are uncommonly seen as complications of lung abscess formation and prompt recognition and treatment is necessary. We present a 59-year-old male patient who complained of shortness of breath and chest pain for 2 weeks. Computed tomography (CT) of the thorax showed a left lower lobe lung abscess. This was associated with leucocytosis and raised C-reactive protein. Ultrasound-guided drainage revealed viscous pus requiring manual aspiration for adequate drainage. The patient later developed extensive pneumomediastinum and subcutaneous emphysema involving the pretracheal space, without evidence of pneumothorax. Left lower lobectomy was performed to control sepsis. The patient achieved a complete recovery following his surgery and antibiotic treatment, with interval resolution of pneumomediastinum and subcutaneous emphysema. We present the radiological and clinical features leading to the diagnosis of pneumomediastinum and subcutaneous emphysema.

1-Year Prospective Study of the Relationship of Serial Exhaled Nitric Oxide Level and Asthma Control.

Background and Objective: Previous studies found that the fractional nitric oxide concentration in exhaled breath (FeNO) levels in healthy Chinese adults was higher than in White adults. More understanding of serial changes of FeNO levels with asthma control in a real-life clinical setting would be important to explore the utility of this biomarker in routine asthma management. This study assessed the FeNO levels of Chinese asthma subjects with different levels of asthma control and the serial changes with respect to the changes in asthma control over 1 year. Methods: A 12-month prospective study (subjects recruited between November 2019 and January 2021) with serial measurement of FeNO levels at baseline, 4, 8 and 12 months. Asthma control was assessed by the Global Initiative for Asthma classification, Asthma Control Test (ACT) and Asthma Control Questionnaire (ACQ). Results: Altogether, 136 subjects (mean age 51.51±15.09 years, 46[33.8%] male) had successful baseline FeNO measurements. At baseline, the FeNO levels did not show a statistically significant difference for controlled, partly controlled and uncontrolled asthma according to GINA classification, ACT and ACQ. FeNO levels decreased with improving asthma control and stayed at similar levels with unchanged or worsening asthma control for all subjects. For subjects with baseline blood eosinophil levels ≥300 cells/µL(n=59), FeNO levels decreased with improving asthma control, stayed similar without change for asthma control and increased with worsening asthma control. Receiver operating characteristic (ROC) analysis with the highest area under curve (AUC) for changes in FeNO levels for improving asthma control was between ≤ -10 to -25 ppb at various time points in the 12-month study. Conclusion: Changes in FeNO levels over time were associated with changes in clinical asthma control, particularly in those with higher blood eosinophil count and are likely more useful than a single time point measurement in managing asthma.

Evaluation of the asthma control test: a reliable determinant of disease stability and a predictor of future exacerbations.

BACKGROUND AND OBJECTIVE: This study assessed the asthma control test (ACT) cut-off values for asthma control according to the Global Initiative for Asthma guideline in adults and the effectiveness of ACT scores in predicting exacerbations and serial changes in ACT scores over time in relation to treatment decisions. METHODS: Subjects completed ACT together with same-day spirometry and fractional concentration of exhaled nitric oxide (FeNO) measurement at baseline and at 3 months. Physicians, blinded to the ACT scores and FeNO values, assessed the patient's asthma control in the past month and adjusted the asthma medications according to management guidelines. Asthma exacerbations and urgent health-care utilization (HCU) at 6 months were recorded. RESULTS: Three hundred seventy-nine (120 men) asthmatics completed the study. The ACT cut-off for uncontrolled and partly controlled asthma were ≤19 (sensitivity 0.74, specificity 0.67, % correctly classified 69.5) and ≤22, respectively (sensitivity 0.73, specificity 0.71, % correctly classified 72.1). Baseline ACT score had an odds ratio of 2.34 (95% confidence interval: 1.48-3.69) and 2.66 (1.70-4.18) for urgent HCU and exacerbations, respectively, at 6 months (P < 0.0001). However, baseline FeNO and spirometry values had no association with urgent HCU and exacerbations. The 3-month ACT score of ≤20 correlated best with step-up of asthma medications (sensitivity 0.65, specificity 0.81, % correctly classified 72.8). For serial changes of ACT scores over 3 months, the cut-off value was best at ≤3 for treatment decisions with low sensitivity (0.23) and % correctly classified (57.3%) values. CONCLUSIONS: Single measurement of ACT is useful for assessing asthma control, prediction of exacerbation and changes in treatment decisions.

Collection of lower respiratory specimen by bronchoscopy for the diagnosis of COVID-19.

Bronchoscopy, as an aerosol-generating procedure, is not routinely performed in patients with high-risk of coronavirus disease-2019 (COVID-19) owing to potential transmission to healthcare workers. However, to obtain lower respiratory specimens from bronchoscopy with bronchoalveolar lavage (BAL) is necessary to confirm COVID-19 or other diagnosis that will change clinical management. We report a case of diagnostic difficulty with five negative SARS-CoV-2 RT-PCR testing in four upper respiratory tract and one stool samples following presentation with fever during the quarantine period and a strong epidemiological linkage to an index patient with COVID-19. The final diagnosis was confirmed by BAL. Special precautions to be taken when performing bronchoscopy in high-risk non-intubated patients were discussed.

Transbronchial microwave ablation of lung nodules with electromagnetic navigation bronchoscopy guidance-a novel technique and initial experience with 30 cases.

BACKGROUND: Microwave ablation of lung nodules may provide a faster, larger and more predictable ablation zone than other energy sources, while bronchoscopic transbronchial ablation has theoretical advantage of fewer pleural-based complications than percutaneous approach. Our study aims to determine whether the novel combination of bronchoscopic approach and microwave ablation in management of lung nodules is technically feasible, safe and effective. METHODS: This is a retrospective analysis of a single center experience in electromagnetic navigation bronchoscopy microwave ablation in hybrid operating room. Patients had high surgical risks while lung nodules were either proven malignant or radiologically suspicious. Primary endpoints include technical feasibility and safety. RESULTS: Total of 30 lung nodules from 25 patients were treated. Mean nodule size was 15.1 mm, and bronchus directly leads to the nodules (bronchus sign positive) in only half of them. Technical success rate was 100%, although some nodules required double ablation for adequate coverage. Mean minimal ablation margin was 5.51 mm. The mean actual ablation zone volume was -21.4% compared to predicted, likely due to significant tissue contraction ranging from 0-43%. There was no significant heat sink effect. Mean hospital stay was 1.73 days, and only 1 patient stayed for more than 3 days. Complications included pain (13.3%), pneumothorax requiring drainage (6.67%), post-ablation reaction (6.67%), pleural effusion (3.33%) and hemoptysis (3.33%). After median follow up of 12 months, none of the nodules had evidence of progression. CONCLUSIONS: Bronchoscopic transbronchial microwave ablation is safe and feasible for treatment of malignant lung nodules. Prospective study on clinical application of this novel technique is warranted.

The long-term impact of severe acute respiratory syndrome on pulmonary function, exercise capacity and health status.

BACKGROUND AND OBJECTIVE: Severe acute respiratory syndrome (SARS) emerged in 2003 and its long-term sequelae remain largely unclear. This study examined the long-term outcome of pulmonary function, exercise capacity, health and work status among SARS survivors. METHODS: A prospective cohort study of SARS patients at the Prince of Wales Hospital, Hong Kong was conducted, with serial assessments of lung function, 6MWD and 36 item Short Form General Health Survey at 3, 6, 12, 18 and 24 months after disease onset. The work status was also recorded. RESULTS: Serial assessments were completed by 55 of the 123 (39.9%) subjects, of whom 27 were health-care workers (HCW). The mean age of the group was 44.4 (SD 13.2) years and 19 (34.5%) were males. At 24 months, 10 (18.2%), 9 (16.4%), 6 (10.9%) and 29 (52.7%) subjects had FEV(1), FVC, TLC and DL(CO) < 80% of predicted values, respectively. The mean (SD) 6MWD increased significantly from 439.0 (89.1) m at 3 months to 460.1 (102.8) m at 6 months (P 0.016) and became steady after 6 months. However, 6MWD and 36 item Short Form General Health Survey scores were lower than the normal population throughout the study. Moreover, 29.6% of HCW and 7.1% of non-HCW had not returned to work 2 years after illness onset. CONCLUSIONS: This 2-year study of a selected population of SARS survivors, showed significant impairment of DL(CO), exercise capacity and health status persisted, with a more marked adverse impact among HCW.

A 1-year prospective study of the infectious etiology in patients hospitalized with acute exacerbations of COPD.

INTRODUCTION: Infection is a major cause of acute exacerbations of COPD (AECOPDs). We aimed to study the infectious etiology related to AECOPD. METHODS: Patients admitted to an acute care hospital in Hong Kong with an AECOPD were recruited prospectively from May 1, 2004, to April 30, 2005. Sputum samples, nasopharyngeal aspirate (NPA) samples, and paired serology specimens were collected. Spirometry was performed with patients in the stable phase 2 to 3 months after hospital discharge. RESULTS: There were 643 episodes of AECOPD among 373 patients. Their mean age was 75.3 years (SD, 7.9 years) with 307 male patients. The mean FEV(1) was 40.4% predicted (SD, 18.7% predicted), and the mean FEV(1)/FVC ratio was 58.4% (SD, 16.0%). Among sputum samples from the 530 episodes of AECOPD hospital admissions that were saved, 13.0%, 6.0%, and 5.5%, respectively, had positive growth of Haemophilus influenzae, Pseudomonas aeruginosa, and Streptococcus pneumoniae. Among the 505 hospital admissions with patients who had NPA samples saved, 5.7%, 2.3%, 0.8%, and 0.8%, respectively, had influenza A, respiratory syncytial virus (RSV), influenza B, and parainfluenza 3 isolated from viral cultures. Paired serology test results revealed a fourfold rise in viral titers in 5.2%, 2.2%, and 1.4% of patients, respectively, for influenza A, RSV, and influenza B. Very severe airflow obstruction (stable-state spirometry) was associated with a higher chance of a positive sputum culture (FEV(1) >/= 30% predicted, 28.2%; FEV(1) < 30% predicted, 40.4%; p = 0.006). CONCLUSION: H influenzae and influenza A were the most common etiologic agents in patients who were hospitalized with AECOPDs. More severe airflow obstruction was associated with a higher chance of a positive sputum culture finding.

COPD care programme can reduce readmissions and in-patient bed days.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a common disease worldwide with significant morbidity and mortality. AIM: To investigate the effect of a comprehensive COPD management programme in decreasing COPD readmissions 1 year before and 1 year after the programme. METHOD: 185 (166 males) patients admitted for acute exacerbation of COPD (AECOPD) were recruited between September 2010 and December 2012. COPD care team provided crisis support and maintenance therapy for the COPD patients for a total of 16 weeks. The protocol included COPD clinic run by respiratory physicians, COPD education and nurse clinics by respiratory nurses, out-patient pulmonary rehabilitation programme by physiotherapists, fast track doctor's clinic, telephone hotline for patients and nurse telephone calls to patients. Readmissions over a period of 1 year were assessed. RESULTS: The mean (SD) age of the subjects and FEV1 % predicted normal were 76.9 ± 7.37 yrs and 44.4 ± 20.7% respectively. 40 (21.6%) patients required non-invasive positive pressure ventilation during the recruitment admission. Admissions for AECOPD decreased from 2.39 ± 2.05 one year before programme to 1.65 ± 2.1 one year after programme (mean difference 0.75 ± 2.11 episodes, p < 0.001). The length of hospital stay was reduced from 12.17 ± 9.14 days one year before programme to 9.09 ± 12.1 days one year after the programme (mean difference 3.09 ± 12.1 days, p < 0.001). The FEV1 percentage predicted and quality of life measured by St George's Respiratory Questionnaire showed no significant improvement at 16 weeks after recruitment into the programme as compared to at 6 weeks. CONCLUSION: COPD care programme is effective in decreasing readmissions and length of hospital day for COPD patients.

Sleep-disordered breathing and continuous positive airway pressure compliance in a group of commercial bus drivers in Hong Kong.

OBJECTIVE AND BACKGROUND: Sleep-disordered breathing may predispose drivers to road traffic accidents. However, CPAP acceptance and compliance among commercial bus drivers is unknown. METHODS: We conducted a sleep questionnaire survey at a bus depot followed by random selection of bus drivers for home sleep study with the mesam iv device. Bus drivers with a respiratory disturbance index (RDI)>or=5/h were invited to have hospital-based polysomnography for confirmation followed by nasal CPAP treatment. RESULTS: Out of 1477 bus drivers, 1016 (971 men) were interviewed with mean (SD) age of 45.3 (7.5) years, BMI 24.9 (3.6) kg/m2, neck circumference 38.9 (3.1) cm and Epworth sleepiness score 4.8 (4.0). Sleepiness at work was reported by 60.9%, snoring>or=3 nights per week 23.9%, witnessed apnoea 3.7% and having fallen asleep during driving by 24%. Among 211 who underwent home sleep study, 85 (40.3%), 55 (26.1%) and 37 (17.5%) had RDI>or=5, >or=10 and >or=15/h respectively. BMI, snoring intensity and neck circumference were the positive independent factors associated with the RDI. Of the 25 drivers who attended polysomnography, nine accepted CPAP prescription with improvement of Epworth sleepiness score, trail B and digit span after 3 months with CPAP usage of 4.5 (1.3) h/night. CONCLUSION: The estimated minimum prevalence rates of sleep-disordered breathing and obstructive sleep apnoea syndrome were 8.4% and 5.4% respectively among the bus drivers. Home CPAP acceptance was low among bus drivers with sleep apnoea but there was significant improvement of subjective sleepiness and cognitive function among those on CPAP treatment.