Search

Obstructive sleep apnoea (OSA) is a common disease, recognized as an independent risk factor for a range of clinical conditions, such as hypertension, stroke, depression and diabetes. Despite extensive research over the past two decades, the mechanistic links between OSA and other associated clinical conditions, including metabolic disorders and cardiovascular disease, remain unclear. Indeed, the pathogenesis of OSA itself remains incompletely understood. This review provides opinions from a number of leading experts on issues related to OSA and its pathogenesis, interaction with anaesthesia, metabolic consequences and comorbidities, cardiovascular disease, genetics, measurement and diagnosis, surgical treatment and pharmacotherapeutic targets.

The treatment of atypical pneumonia, subsequently termed severe acute respiratory syndrome (SARS), is controversial, and the efficacy of corticosteroid therapy is unknown. We have evaluated the clinical and radiographic outcomes of 72 patients with probable SARS (median age 37 years, 30 M), who received ribavirin and different steroid regimens in two regional hospitals. Chest radiographs were scored according to the percentage of lung field involved. Seventeen patients initially received pulse steroid (PS) (methylprednisolone > or =500 mg/day) and 55 patients initially received nonpulse steroid (NPS) (methylprednisolone

Background Information on the clinical features of the severe acute respiratory syndrome (SARS) will be of value to physicians caring for patients suspected of having this disorder. Methods We abstracted data on the clinical presentation and course of disease in 10 epidemiologically linked Chinese patients (5 men and 5 women 38 to 72 years old) in whom SARS was diagnosed between February 22, 2003, and March 22, 2003, at our hospitals in Hong Kong, China. Results Exposure between the source patient and subsequent patients ranged from minimal to that between patient and health care provider. The incubation period ranged from 2 to 11 days. All patients presented with fever (temperature, >38°C for over 24 hours), and most presented with rigor, dry cough, dyspnea, malaise, headache, and hypoxemia. Physical examination of the chest revealed crackles and percussion dullness. Lymphopenia was observed in nine patients, and most patients had mildly elevated aminotransferase levels but normal serum creatinine levels...

The pattern of pulmonary infections in 59 consecutive bone marrow transplantations in Hong Kong was reviewed. Compared with published data from other marrow transplant units, we had a lower incidence of cytomegalovirus pneumonitis (1.7%) and a higher incidence of mycobacterial infections (5%). The latter is probably related to the high background prevalence of tuberculosis in the local population. Treatment with antituberculous drugs was effective.

Session B71. Crazy Muscles: Airway and Lymphatic Smooth Muscle and Lymphangioleiomyomatosis (LAM): abstract no. A3656

We studied the changes in sputum neutrophil chemotactic activity (NCA) and elastolytic activity (EA) in acute exacerbations of bronchiectasis before and after treatment with oral antibiotics. Twelve patients who chronically produced sputum were assessed in the stable state, and when they subsequently developed symptoms of acute exacerbations, prior to initiation of antibiotics, during 2 weeks of antibiotics, and at 2 and 6 weeks after stopping antibiotics. NCA was measured using modified Boyden's technique with multiwell chemotaxis chamber, and EA with N-succiny-trialanine-p-nitroanilide as elastase substrate. All 12 patients had NCA (49·3 ± 8·69% FMLP response) and EA (50·5 ± 17·1 mU per 100 μl) in their sputum in the stable state. At acute exacerbation, there was significant increase in NCA (P < 0·001) and EA (P < 0·05). All responded clinically after 1 week of antibiotics, and this was associated with a decrease in NCA and EA back to the levels in stable state. A further week of antibiotics did not result in further decline of NCA or EA. Three patients had another acute exacerbation clinically between 2–6 weeks after stopping antibiotics and their NCA and EA rose again. In the other nine patients, both NCA and EA at 2 and 6 weeks post-treatment were similar to pre-exacerbation levels. Our findings suggest that short course antibiotics effectively control the upsurge in inflammatory activity in acute axacerbations, but has little effect on chronic airway inflammation. This would challenge the validity of such a treatment strategy which is still the most common in clinical practice, when persistent airway inflammation is believed to lead to progressive lung destruction.

To audit the clinical practice in drug treatment of bronchial asthma in Hong Kong, two questionnaire surveys were conducted in 1987 and 1992. The questionnaire was adapted from the 1984 European Audit. The response rate was 40% (248 of 615 mailings) in 1987 and 32% (207 of 652 mailings) in 1992. A total of 86% and 87% of responders were general practitioners (GP), respectively, and the others were chest physicians (CP). For treatment of acute severe asthma in adults, parenteral aminophylline was the first drug used by GP in 1987, whereas inhaled beta-agonist was used in 1992. Parenteral steroid was more often used by both GP and CP in 1992. In children, inhaled beta-agonist was always the first choice and parenteral steroid ranked higher in 1992, overtaking parenteral aminophylline. For maintenance therapy of chronic asthma in adults, inhaled beta-agonist ranked first in both surveys. Inhaled steroid has become much more popular with GP, ranking second in 1992, overtaking oral bronchodilators. With CP, inhaled steroid was already ranking second in 1987, and it was used as the first drug, as frequently as inhaled beta-agonist, in 1992. In children, in 1987, inhaled beta-agonist was the first drug of choice, and prophylactic drugs ranked lower than oral bronchodilators with both GP and CP. In 1992, cromoglycate and inhaled steroids were much more often used, so much so that among CP, inhaled steroid ranked first, just ahead of inhaled beta-agonist.(ABSTRACT TRUNCATED AT 250 WORDS)

Session - B73 Sleep Disordered Breathing and Control of Ventilation: Basic and Translational Aspects

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.

Purpose 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. Method Retrospective review of NSCLC patients with favourable clinical features who received gefitinib as firstline treatment and subsequent salvage treatment with erlotinib. Results 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. Conclusion For NSCLC patients with favourable clinical features, erlotinib was effective in those who had prior disease control with first-line gefitinib. © Springer-Verlag 2009., published_or_final_version, Springer Open Choice, 01 Dec 2010

A group of bronchiectatic subjects in the clinically stable state were studied for systemic evidence of inflammation. The following parameters were evaluated: body weight, serum albumin, serum globulin, serum alpha 1-antitrypsin (alpha 1 AT) and peripheral white cell count. For serum albumin and globulin, comparison was made between subjects with bronchiectasis and control subjects with no known pulmonary disease matched for sex and age, and for serum alpha 1 AT and peripheral white cell count, matched for smoking habit as well. The bronchiectatic subjects showed systemic effects of inflammation as indicated by lower body weight and serum albumin (P less than 0.01), higher serum globulin (P less than 0.001), serum alpha 1 AT (P less than 0.05) and total leucocyte count (P less than 0.05). Differential white cell count showed that the elevation was distributed in most cell types. Correlation matrix was done for the above systemic parameters and indices of airway inflammation including sputum volume, purulence, and polymorph count and FEV1. There was an inverse correlation between total peripheral WBC count and FEV1 in percentage of predicted (P less than 0.01), and a positive correlation between sputum purulence and sputum polymorph score (P less than 0.05). This suggests that host peripheral leucocyte response may be a factor in the determination of lung function.

Objective: To evaluate dentofacial characteristics in relation to obesity and degree of severity of obstructive sleep apnea (OSA) in male Chinese patients and to elucidate the relationship between demographic parameters (age, body weight, height, and body mass index [BMI]) cephalometric parameters and OSA in these subjects. Materials and Methods: Lateral cephalograms of 121 Chinese male patients in natural head posture were obtained. Based on BMI value, the patients were divided into three groups. Based on apnea-hypopnea index (AHI) value, the patients were divided into a mild-to-moderate and a severe group. Results: The hyoid position and soft palate length were significantly different among the three obesity groups. Soft palate length was significantly longer (P < .01) in the severe OSA group than in the mild-to-moderate OSA group. Tongue base was significantly more inferiorly placed (P < .05) in the severe OSA group than in the mild-to-moderate OSA group. Craniocervical extension was significantly increased (P < .05) in the severe OSA group. Statistically significant differences were found among the three obesity groups in mandibular length, mandibular body length, maxillary length, anterior cranial base length, and overbite. The multiple stepwise linear regression analysis identified body weight, lower posterior facial height, mandibular body length, craniocervical extension, and sella-hyoid distance as the significant predictive variables for AHI. Conclusions: This study revealed the existence of craniofacial and upper airway soft tissue differences in relation to obesity and severity of OSA among male Chinese OSA patients. Body weight and certain cephalometric parameters were significant predictors of OSA in Chinese male subjects.

Lymphangioleiomyomatosis (LAM) is a rare parenchymal lung disease, which affects young women of childbearing age and is characterized pathologically by proliferation of interstitial smooth muscle and formation of cysts in the lung. While LAM is usually predominantly a respiratory disorder, it can also initially involve other extrapulmonary organs. We report the case of a 35-year-old Chinese woman, who presented with a 4-week history of left thigh swelling which was found to be secondary to compression of pelvic veins by a mass lesion. The latter was found histologically to show LAM. Despite the patient being asymptomatic and displaying normal lung function, a thoracic high resolution CT scan showed typical features of early LAM. This case further illustrates that LAM can have multisystem involvement, and demonstrates the importance of being aware of the diagnosis in cases presenting with extrapulmonary manifestation, in order that patients are diagnosed and managed appropriately.

A 50-year-old Chinese lady presented with subacute onset of dyspnoea, bilateral infiltrates on chest X-ray and type I respiratory failure. There were minor symptoms of arthralgia and myalgia. Subsequent investigations confirmed that she had organizing pneumonia, polymyositis and serum anti-Jo-1 antibody. Treatment with corticosteroids resulted in prompt improvement of the respiratory condition and myositis.

A case of subclinical disseminated intravascular coagulopathy due to antituberculosis drugs, probably rifampicin, is described. The patient also developed marked leucocytosis, a 'flu-like illness, intravascular haemolysis, and acute renal failure as part of the drug reaction.

Helicobacter pylori causes chronic inflammation of the gastric mucosa and has been identified in tracheobronchial secretions. Serum IgG against H. pylori was therefore measured prospectively in consecutive subjects with bronchiectasis (n = 100; mean age +/- SD 55.1 +/- 16.7 yr), active pulmonary tuberculosis (n = 87; age, 57.3 +/- 19.1 yr), and healthy volunteers (n = 94; age, 54.6 +/- 7.6 yr). Seropositivity was found in 76.0% of bronchiectatic subjects, which was significantly higher than that of the control (54.3%, p = 0.001) and tuberculous (52.9%, p = 0.0001) groups. Multiple logistic regression, adjusted for age, sex, occupational social class, and number of persons living in the household, showed that H. pylori IgG levels of the bronchiectatic group were still significantly higher than that of the control (p = 0.0014) and tuberculous (p = 0.0154) groups. Multiple regression analysis revealed associations between H. pylori serology and sputum volume (p = 0.03) and age (p = 0.001) in the bronchiectatic patients, but not lung function indices or causes of bronchiectasis. The H. pylori seroprevalence in bronchiectasis was significantly (p = 0.0002) higher in patients who produced more (83.1%) than those who produced less than 5 ml sputum/24 h (58.6%). This is the first report of a high H. pylori seroprevalence in bronchiectasis which appears to be specific. Further studies are indicated to evaluate the possible pathogenic role of H. pylori in bronchiectasis.

SUMMARY A 62 year old Chinese woman presented 25 years after having both breasts augmented with paraffin injections. Development of paraffinomas and multiple episodes of paraffin-related mastitis eventually resulted in bilateral mastectomies. The unusual distribution of migrated calcified paraffinomas in the thoracic wall and its lymphatic system is documented on computed tomography.

The trend in asthma mortality in Hong Kong was estimated from published statistics for the years 1976-85. To avoid coding errors in death certifications, only asthma deaths in the age group 5-34 years were analysed. Mortality rose annually by an average of 10.5% in male (P less than 0.02), but not female asthmatics. Such an increase was not due to a change in coding as a result of the revision of the International Classification of Diseases in 1979, or an exchange of diagnostic labelling from other respiratory diseases. The exact causes for the increase in asthma mortality have yet to be determined.

Nonspecific bronchial hyperreactivity (BHR) has been reported to occur in patients with bronchiectasis. To evaluate this further, we studied 77 patients with stable bronchiectasis (noncystic fibrosis) with special reference to the prevalence of BHR to methacholine (MCh), and its relation to lung function, sputum characteristics, concommitant asthma, and atopy. The concentration of MCh required to produce a fall of 20% in forced expiratory volume in 1 s (FEV1), PC20, was determined by Wright's nebulization tidal breathing method. BHR defined by a PC20 greater than or equal to 8 mg/ml was found in 21 of 47 (45%) subjects who underwent bronchial challenge. Presence of BHR was positively associated with low baseline spirometric values, diagnosis of asthma, long duration of disease, and elevated total IgE on univariant analysis, and was significantly related to FEV1/forced vital capacity (FVC) ratio and asthma on multiple regression analysis. Ten of the 21 hyperreactive subjects did not have clinical asthma, whereas all 11 of 22 subjects with clinical asthma who underwent bronchial challenge were hyperreactive. Among those with BHR, there was a positive correlation between PC20 and baseline FEV1. When patients were further classified into asthmatic and nonasthmatic subjects, a positive correlation between PC20 and FEV1 was seen only in those without asthma. Frequency of infective episodes and inflammatory score of sputum assessed by average daily volume, purulence, and leukocyte count did not differ significantly in the groups with and without BHR. These results suggest that BHR in patients with bronchiectasis is associated with coexistent asthma and worse spriometric values, and not with the severity of bronchial sepsis.

An increase in cytoplasmic Ca++ concentration can activate not only respiratory smooth muscles, but also mast cells, bronchial mucus glands, and the vagi. Altered control of cytoplasmic Ca++ may also be related to the development of bronchial hyperreactivity. Drugs that block Ca++ influx through specific Ca++ channels in plasma membranes are therefore expected to be effective in the treatment of asthma. Reports so far indicate that such drugs may enhance the action of bronchodilators and may offer partial protection against histamine- or methacholine-induced broncho-constriction; but they neither modify the basal bronchomotor tone of asthmatics nor reverse established bronchoconstriction. Calcium-channel blockers are also weak inhibitors of mediator release from mast cells except at high concentrations, which partly explains their inconsistent blocking activity in allergen-induced asthma. However, they are usually effective in preventing exercise-induced bronchoconstriction. They offer an alternative treatment for patients with chronic airflow obstruction who needβ-adrenergic blockade for coexisting cardiovascular problems. Limited data suggest that long-term use of calcium-channel blockers may benefit patients with chronic asthma. The therapeutic role of currently available Ca++-channel blockers is limited in asthma in view of their low potency; more specific airway Ca++ antagonists need to be developed.

We review the results of bronchial aspirate culture for mycobacteria sent routinely in a series of 1734 fibreoptic bronchoscopic procedures. The incidence of tuberculosis in the series was 8.3 % (144 cases). Of these cases, a positive bronchial aspirate culture was obtained in 119 (82.6 %) cases, and it was the exclusive means of diagnosis in 64 (44.4 %). In 66 % of these cases tuberculosis was not suspected at the time of bronchoscopy. Our results suggest that in an area with a high prevalence of tuberculosis, routine bronchial aspirate culture is a useful adjunct to diagnosis.