Nonorganic upper airway obstruction

Two cases of severe dyspnea and stridor with upper airway obstruction of obscure origin are discussed. Complete medical evaluation could identify no organic cause for the symptoms, and functional upper airway obstruction was diagnosed. Treatment with psychotherapy and relaxation techniques was successful. Diagnosis can be made with pulmonary function studies. Flow-volume loops may show a lower inspiratory vital capacity than expiratory vital capacity and a discrepancy between inspiratory flow limitation and airway resistance. It is important to establish a functional etiology to prevent unnecessary treatment and provide proper care.     

Pulmonary function tests in acute bronchitis: evidence for reversible airway obstruction

Acute bronchitis is a common syndrome characterized by upper respiratory tract infection accompanied by productive cough in persons without chronic lung disease. As a first step in investigating the potential role of pulmonary airflow disturbances in acute bronchitis, 27 adult patients with acute bronchitis performed serial pulmonary function tests and daily peak flow measurements and completed daily symptom diaries. Eleven patients (40 percent) had a forced expiratory volume of the first second (FEV1) at entry less than 80 percent of predicted. Mean FEV1, forced midexpiratory flow rate (FEF25-75), and peak flow measures showed steady improvement over the five-week period. Differences between initial and final flow rates were statistically significant. These changes were particularly evident when two groups were created by stratifying by "abnormal" (FEV1 less than or equal to 80 percent predicted) and "normal" (FEV1 greater than 80 percent predicted) initial FEV1. Total duration of cough and subjective ratings of cough severity were not predicted by initial FEV1, but work absence was significantly higher in the abnormal group. The finding of reversible airway obstruction suggests a role for bronchospasm in many cases of acute bronchitis and calls for further research regarding proof of rapid reversibility and treatment with bronchodilators.     

上尿路结石致急性梗阻性无尿46例腔内治疗体会

目的 探讨输尿管镜腔内技术治疗上尿路结石致急性梗阻性无尿的疗效与安全性.方法 2001年2月至2008年6月采用输尿管镜腔内技术治疗上尿路结石致急性梗阻性无尿患者46例,其中41例行经尿道输尿管镜取石术,5例行经皮肾微造瘘输尿管镜取石术.结果 患者平均手术时间(61.2±10.2)min,术中平均出血量(58.0±15.6)ml.术后尿量增多,最多者达5000 ml/d.术后平均住院时间(9.4±0.9)d.1周后复查血肌酐在75～240μmol/L,1个月后复查血肌酐仍稳定在同一水平.术后所有患者输尿管内均不再存留结石;4例输尿管上段结石行输尿管镜取石术中结石上移至肾内者术后行体外冲击波碎石术,1个月后拔除双J管.所有患者均未出现感染性休克、输尿管穿孔、撕脱、断裂等严重并发症.结论 输尿管镜腔内碎石术是治疗上尿路结石致梗阻性急性肾衰竭的首选治疗方法,具有安全、微创、有效的特点,有临床推广价值.     

Airway oedema and obstruction in guinea pigs exposed to inhaled endotoxin.

Protein extravasation and airway conductance (SGaw) were examined in awake guinea pigs exposed to inhaled endotoxin or saline for three hours. A significant increase in protein extravasation (as estimated by the leakage of protein bound Evans blue dye) was seen in the conducting airways of endotoxin exposed animals compared with saline exposed animals. Mean dye extravasation was significantly increased by one to threefold in the mainstem and hilar bronchi of endotoxin exposed animals. These changes in extravasation were accompanied by decrements in pulmonary function and by an influx of polymorphonuclear leucocytes into the airway wall. The SGaw decreased significantly by 60-90 minutes into exposure to endotoxin and had decreased by 22% and 34% at the end of exposure in the low and high dose endotoxin groups, respectively. Similar findings were obtained in animals exposed to cotton dust. Contrary to studies suggesting that platelet activating factor (PAF) is involved in the systemic and peripheral lung effects of endotoxin, pretreatment with the PAF antagonist WEB2086 did not prevent the conducting airway injury produced by inhaled endotoxin.     

Serum retinol and airway obstruction

The relation of serum retinol and carotenoids to airway obstruction was investigated in a population-based study. Respiratory symptoms and the pulmonary function of 83 white males were assessed in 1979 5 years after their blood had been drawn. Airway obstruction in 1979, defined as a forced expiratory volume in 1 second which was equal to or less than 75% of the forced vital capacity, was associated with a decreased 1974 level of serum retinol.     

Work related distal airway obstruction in an agricultural population.

OBJECTIVE--To assess the prevalence of distal airway obstruction and its risk factors in agricultural areas. METHODS--A cross sectional study of respiratory symptoms and lung function was performed among French farmers and their spouses (1122 subjects) who came for preventive medicine examinations. They answered a respiratory questionnaire and performed pulmonary function tests on a portable spirometer. Diagnoses of chronic bronchitis were made on the basis of reported chronic respiratory symptoms. Airway obstruction was determined from predicted values. Odds ratio (OR) and linear regression coefficients were calculated after stratification by smoking and history of cardiac and other respiratory diseases. RESULTS--Of respiratory symptoms prevalence of chronic cough was 8.47%, and chronic bronchitis 7.66%. Prevalence of distal airway obstruction was 11.4%, and overall airflow obstruction 3.2%. Smokers were 20.2% men, and 5.7% women. Linear regressions showed high association between pack-years in smokers or exsmokers and forced expiratory volume in one second/forced vital capacity (FEV1/VC) and forced expiratory flow between 25% and 75% of vital capacity (FEF25-75). In non-smokers without any history of cardiac or respiratory diseases, age and the size of farms had the highest correlations with these variables. OR for distal airway obstruction was 2.1 in subjects > 50 years old v the younger ones and 3.02 in the smaller farms v the larger ones. CONCLUSION--After stratification by smoking and history of cardiac and respiratory diseases, distal airway obstruction is present in agricultural areas. The age, and the size of farm are the highest respiratory risk factors in non-smokers.     

Climate and environment change in patients with chronic airway obstruction.

Psychological, clinical, and pulmonary physiological measurements were studied in ten patients with weather-sensitive chronic airway obstruction during one month in Gothenburg, Sweden, and immediately after for one month in the Canary Islands, a change to a drier and warmer climate. All patients improved according to psychological tests and claimed to be better. Objective measurements including peak expiratory flow rate, airway conductance, static lung volumes, and elastic lung recoil showed improvement in eight of ten patients, a change that we believe is due to the effect of climate.     

Airway oedema and obstruction in guinea pigs exposed to inhaled endotoxin

Protein extravasation and airway conductance (SGaw) were examined in awake guinea pigs exposed to inhaled endotoxin or saline for three hours. A significant increase in protein extravasation (as estimated by the leakage of protein bound Evans blue dye) was seen in the conducting airways of endotoxin exposed animals compared with saline exposed animals. Mean dye extravasation was significantly increased by one to threefold in the mainstem and hilar bronchi of endotoxin exposed animals. These changes in extravasation were accompanied by decrements in pulmonary function and by an influx of polymorphonuclear leucocytes into the airway wall. The SGaw decreased significantly by 60-90 minutes into exposure to endotoxin and had decreased by 22% and 34% at the end of exposure in the low and high dose endotoxin groups, respectively. Similar findings were obtained in animals exposed to cotton dust. Contrary to studies suggesting that platelet activating factor (PAF) is involved in the systemic and peripheral lung effects of endotoxin, pretreatment with the PAF antagonist WEB2086 did not prevent the conducting airway injury produced by inhaled endotoxin.