Treatment-emergent central sleep apnoea managed by CPAP with adjunctive acetazolamide: A case report.

Treatment-emergent central sleep apnoea (TECSA) refers to the emergence of central apnoea during treatment for obstructive sleep apnoea (OSA), most commonly continuous positive airway pressure (CPAP). It has been reported in 8% of OSA patients treated with CPAP and spontaneous resolution rate varies between 60% and 80%. Management options include watchful waiting with continuation of CPAP, bi-level positive pressure ventilation, adaptive servo-ventilation and CPAP with supplemental oxygen. Acetazolamide has been shown to be effective in other forms of central sleep apnoea; its use as adjunct to CPAP in TECSA is sparsely reported. We report a 74-year-old man with severe OSA who developed moderate central apnoea upon CPAP initiation. Subsequent addition of acetazolamide led to gratifying resolution of the TECSA. In TECSA patients with significant symptoms and high central apnoea index, treatment with acetazolamide as adjunct to CPAP may be considered, particularly in patients in whom CPAP adherence is imperative.

A territory-wide study on the factors associated with recurrent asthma exacerbations requiring hospitalization in Hong Kong.

BACKGROUND: The real-world relationships between the demographic and clinical characteristics of asthma patients, their prehospitalization management and the frequency of hospitalization due to asthma exacerbation is poorly established. OBJECTIVE: To determine the risk factors of recurrent asthma exacerbations requiring hospitalizations and evaluate the standard of baseline asthma care. METHODS: A territory-wide, multicentre retrospective study in Hong Kong was performed. Medical records of patients aged ≥18 years admitted to 11 acute general hospitals from January 1 to December 31, 2016 for asthma exacerbations were reviewed. RESULTS: There were 2280 patients with 3154 admissions (36.7% male, median age 66.0 [interquartile range: 48.0-81.0] years, 519 had ≥2 admissions). Among them, 1830 (80.3%) had at least one asthma-associated comorbidity, 1060 (46.5%) and 885 (38.9%) of patients had Accident and Emergency Department (AED) attendance and hospitalization in the preceding year, respectively. Patients with advancing age (incidence rate ratio [IRR]: 1.003 for every year increment), a history of AED visits or hospitalization (IRR: 1.018 and 1.070 for every additional episode, respectively) for asthma exacerbation in the preceding year, the presence of neuropsychiatric (IRR: 1.142) and gastrointestinal (IRR: 1.154) comorbidities were risk factors for an increasing number of admissions for asthma exacerbation. For patients with ≥2 admissions, 17.1% were not prescribed inhaled corticosteroid and only 44.6% had spirometry checked before the index admission. Asthma phenotyping was often incomplete, as assessment of atopy (total serum immunoglobulin E level and senitization to aeroallergens) was only performed in 30 (5.8%) patients with ≥2 admissions. CONCLUSIONS AND CLINICAL RELEVANCE: Improving asthma care, especially in elderly patients with a prior history of urgent healthcare utilization and comorbidities, may help reduce healthcare burden. Suboptimal management before the index admission was common in patients hospitalized for asthma exacerbations. Early identification of patients at risk and enhancement of baseline asthma management may help to prevent recurrent asthma exacerbation and subsequent hospitalization.

Accuracy of forced oscillation technique to assess lung function in geriatric COPD population.

INTRODUCTION: Performing lung function test in geriatric patients has never been an easy task. With well-established evidence indicating impaired small airway function and air trapping in patients with geriatric COPD, utilizing forced oscillation technique (FOT) as a supplementary tool may aid in the assessment of lung function in this population. AIMS: To study the use of FOT in the assessment of airflow limitation and air trapping in geriatric COPD patients. STUDY DESIGN: A cross-sectional study in a public hospital in Hong Kong. ClinicalTrials.gov ID: NCT01553812. METHODS: Geriatric patients who had spirometry-diagnosed COPD were recruited, with both FOT and plethysmography performed. "Resistance" and "reactance" FOT parameters were compared to plethysmography for the assessment of air trapping and airflow limitation. RESULTS: In total, 158 COPD subjects with a mean age of 71.9±0.7 years and percentage of forced expiratory volume in 1 second of 53.4±1.7 L were recruited. FOT values had a good correlation (r=0.4-0.7) to spirometric data. In general, X values (reactance) were better than R values (resistance), showing a higher correlation with spirometric data in airflow limitation (r=0.07-0.49 vs 0.61-0.67), small airway (r=0.05-0.48 vs 0.56-0.65), and lung volume (r=0.12-0.29 vs 0.43-0.49). In addition, resonance frequency (Fres) and frequency dependence (FDep) could well identify the severe type (percentage of forced expiratory volume in 1 second <50%) of COPD with high sensitivity (0.76, 0.71) and specificity (0.72, 0.64) (area under the curve: 0.8 and 0.77, respectively). Moreover, X values could stratify different severities of air trapping, while R values could not. CONCLUSION: FOT may act as a simple and accurate tool in the assessment of severity of airflow limitation, small and central airway function, and air trapping in patients with geriatric COPD who have difficulties performing conventional lung function test. Moreover, reactance parameters were better than resistance parameters in correlation with air trapping.

Frequent Exacerbator: The Phenotype at Risk of Depressive Symptoms in Geriatric COPD Patients.

INTRODUCTION: Depression is associated with a poorer quality of life and higher rate of COPD exacerbations and mortality. However, with multiple confounding factors, 'independent' risk factor for depression among COPD patients remains ambiguous. Our study aims to identify independent risk factors for depression by specifically evaluating for any independent relationship between frequent exacerbations and various domains of the BODE index on depression. METHODS: This study is a cross-sectional study, conducted in Hong Kong SAR. Age and comorbidity-matched COPD and control subjects were recruited. Depressive symptoms were measured by a validated Chinese version of the Geriatric Depression Scale (GDS-15 items). Prevalence rates of depressive symptoms were compared between COPD and control groups. Predictors for depression (GDS ≥ 8) were determined using univariate and multivariate analyses. RESULTS: A total of 161 patients (89 and 72 patients, mean ages 75.2 and 75.6 in COPD and control group, respectively) were recruited. Higher prevalence rate of significant depressive symptoms was seen in COPD patients (20.2 vs. 4.2 %, p = 0.006*). Univariate analysis suggested that predictors for depression in COPD patients included (i) exacerbation frequencies in prior year, (ii) dyspnea level, (iii) BMI, (iv) functional status (Barthel index, 6MWD, activity domain of SGRQ), and (v) BODE index. In multivariate analysis, only the 'exacerbation frequencies in prior year' (OR 1.46, p = 0.042*) and 'dyspnea level' (MMRC) (OR 2.75, p = 0.001*) remained significant independent predictors for depression in COPD patients. CONCLUSIONS: A high prevalence of depressive symptoms was observed in COPD patients. 'Frequent exacerbation phenotype' remained a significant independent predictor for depressive symptoms in COPD. Among the BODE index domains, dyspnea level is the most important predictor for depression in COPD patients.

Benefits of high-dose N-acetylcysteine to exacerbation-prone patients with COPD.

BACKGROUND: Although high-dose N-acetylcysteine (NAC) has been suggested to reduce COPD exacerbations, it is unclear which category of patients with COPD would benefit most from NAC treatment. The objective of this study was to compare the effect of high-dose NAC (600 mg bid) between high-risk and low-risk Chinese patients with COPD. METHODS: Patients with spirometry-confirmed stable COPD were randomized to treatment with either NAC 600 mg bid or placebo in addition to their usual treatments. Patients were followed up every 16 weeks for a total of 1 year. Further analysis was performed according to each patient's exacerbation risk at baseline as defined by the current GOLD (Global Initiative for Chronic Obstructive Lung Disease) strategy to analyze the effect of high-dose NAC in high-risk and low-risk patients. RESULTS: Of the 120 patients with COPD randomized (men, 93.2%; mean age, 70.8 ± 0.74 years; prebronchodilator FEV1, 53.9 ± 2.0%; baseline characteristics comparable between treatment groups), 108 (NAC, 52; placebo, 56) completed the 1-year study. For high-risk patients (n = 89), high-dose NAC compared with placebo significantly reduced exacerbation frequency (0.85 vs 1.59 [P = .019] and 1.08 vs 2.22 [P = .04] at 8 and 12 months, respectively), prolonged time to first exacerbation (P = .02), and increased the probability of being exacerbation free at 1 year (51.3% vs 24.4%, P = .013). This beneficial effect of high-dose NAC vs placebo was not significant in low-risk patients. CONCLUSIONS: High-dose NAC (600 mg bid) for 1 year reduces exacerbations and prolongs time to first exacerbation in high-risk but not in low-risk Chinese patients with COPD. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01136239; URL: www.clinicaltrials.gov.

High-dose N-acetylcysteine in stable COPD: the 1-year, double-blind, randomized, placebo-controlled HIACE study.

BACKGROUND: The mucolytic and antioxidant effects of N-acetylcysteine (NAC) may have great value in COPD treatment. However, beneficial effects have not been confirmed in clinical studies, possibly due to insufficient NAC doses and/or inadequate outcome parameters used. The objective of this study was to investigate high-dose NAC plus usual therapy in Chinese patients with stable COPD. METHODS: The 1-year HIACE (The Effect of High Dose N-acetylcysteine on Air Trapping and Airway Resistance of Chronic Obstructive Pulmonary Disease-a Double-blinded, Randomized, Placebo-controlled Trial) double-blind trial conducted in Kwong Wah Hospital, Hong Kong, randomized eligible patients aged 50 to 80 years with stable COPD to NAC 600 mg bid or placebo after 4-week run-in. Lung function parameters, symptoms, modified Medical Research Council (mMRC) dyspnea and St. George's Respiratory Questionnaire (SGRQ) scores, 6-min walking distance (6MWD), and exacerbation and admission rates were measured at baseline and every 16 weeks for 1 year. RESULTS: Of 133 patients screened, 120 were eligible (93.2% men; mean age, 70.8±0.74 years; %FEV1 53.9±2.0%). Baseline characteristics were similar in the two groups. At 1 year, there was a significant improvement in forced expiratory flow 25% to 75% (P=.037) and forced oscillation technique, a significant reduction in exacerbation frequency (0.96 times/y vs 1.71 times/y, P=.019), and a tendency toward reduction in admission rate (0.5 times/y vs 0.8 times/y, P=.196) with NAC vs placebo. There were no significant between-group differences in mMRC dypsnea score, SGRQ score, and 6MWD. No major adverse effects were reported. CONCLUSION: In this study, 1-year treatment with high-dose NAC resulted in significantly improved small airways function and decreased exacerbation frequency in patients with stable COPD. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01136239; URL: www.clinicaltrials.gov.

A comparative study of clinical features and outcomes in young and older adults with severe acute respiratory syndrome.

OBJECTIVES: To determine the clinical presentation, findings, and outcomes of older adults (> 60) with severe acute respiratory syndrome (SARS) and compare these with a control group of younger patients (< or or =60). DESIGN: Retrospective cohort study. SETTING: A community-based, acute hospital in Hong Kong. PARTICIPANTS: All adult inpatients with a clinical diagnosis of SARS. MEASUREMENTS: Clinical presentations, investigations, treatment, and 30- and 150-day mortality. RESULTS: There were 52 young and 25 older patients with a mean age +/- standard deviation of 39.5+/-11.7 and 72.1+/-7.2, respectively. Fever, chills, and diarrhea were more common in younger patients, whereas decrease in appetite and general condition occurred only in older patients. The prevalence of positive reverse-transcriptase polymerase chain reaction for SARS-associated coronavirus (SARS-CoV) in nasopharyngeal secretions and stool samples was similar in the two groups. The prevalence of positive serological tests for SARS-CoV was significantly lower in older patients (42% vs 92%, P<.001). This was largely due to incomplete testing in elderly patients. Older patients were more likely to develop secondary nosocomial infection, be admitted to an intensive care unit, and require mechanical ventilation. The cumulative 30- and 150-day mortality rates were 3.8% and 7.6%, respectively, in young patients with SARS and 56% and 60%, respectively, in older patients (P<.001). CONCLUSION: Older patients with SARS more often presented with nonspecific symptoms, and the prognosis was poor. Reverse-transcriptase polymerase chain reaction was useful in diagnosing SARS in older patients, but the role of serological tests in individual elderly is limited.