Search of a Paradoxical Fall in Maximum Expiratory Flow After Bronchodilation in Healthy Subjects
试验速览
- 阶段
- 不适用
- 入组人数
- 65
- 试验地点
- 1
- 主要终点
- Occurrence or increase of the Expiratory Flow Limitation (EFL) under either Negative Expiratory Pressure (NEP) or submaximal gentle forced expiratory manoeuvres (partial flow-volume loops at tidal volume)
研究概览
简要总结
There exists a physiological limitation of the expiratory flows because of the physical properties of the bronchial tree (flexible bronchial walls in a complex architecture subjected to variations of pressure and volume). For a given lung, in a given state, for each pulmonary volume there is a corresponding Maximum Expiratory Flow (MEF). In healthy subject, the bronchial smooth muscles have a basal tonicity which is not negligible. If the tonicity is increased, this generally leads to a reduction in MEF. If it is decreased, MEF rather tends to increase, there are healthy individuals for whom the inhibition of the contraction of the bronchial smooth muscles by inhalation of bronchodilatator leads to a reduction in the MEF: this is called "paradoxical effect". When this reduction exists, it appears it occurs at low pulmonary volumes (approximately 50% for a volume of less than 25% of the CV). Under this circumstance, it seems that the basal tonicity of the bronchial smooth muscles would fight against the expiratory collapse of the bronchi, and this would happen especially for distal bronchi, for low pulmonary volume and for forceful expiration. The existence of such a phenomenon would be in favour of a "stiffening" role of the bronchial smooth muscles. The bronchial smooth muscles would not be only harmful cells causing of the asthma attacks.
详细描述
There exists a physiological limitation of the expiratory flows because of the physical properties of the bronchial tree (flexible bronchial walls in a complex architecture subjected to variations of pressure and volume). For a given lung, in a given state, for each pulmonary volume there is a corresponding Maximum Expiratory Flow (MEF). In healthy subject, the bronchial smooth muscles have a basal tonicity which is not negligible. If the tonicity is increased, this generally leads to a reduction in MEF. If it is decreased, MEF rather tends to increase, there are healthy individuals for whom the inhibition of the contraction of the bronchial smooth muscles by inhalation of bronchodilatator leads to a reduction in the MEF: this is called "paradoxical effect". When this reduction exists, it appears it occurs at low pulmonary volumes (approximately 50% for a volume of less than 25% of the CV). Under this circumstance, it seems that the basal tonicity of the bronchial smooth muscles would fight against the expiratory collapse of the bronchi, and this would happen especially for distal bronchi, for low pulmonary volume and for forceful expiration. The existence of such a phenomenon would be in favour of a "stiffening" role of the bronchial smooth muscles. The bronchial smooth muscles would not be only harmful cells causing of the asthma attacks.
Primary end-point:
The aim of this study is to evaluate the occurrence or increase of the Expiratory Flow Limitation (EFL) under either Negative Expiratory Pressure (NEP) or submaximal gentle forced expiratory manoeuvres (partial flow-volume loops at tidal volume) after bronchodilation in certain healthy men breathing at low pulmonary volumes (by applying a chest wall strapping).
Secondary end-point:
The secondary objectives are
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Diagnostic
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 35 Years（Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •All the volunteers will:
- •be between 18 and 35 years/old
- •be male (because of binding thoracic, more difficult to realize and more uncomfortable in the female subjects)
- •have to understand French
- •have to be affiliated to the social security
- •have to be "non smokers, or having never smoked"
- •have to have read and have understood the information record
- •have to have signed the informed consent
- •have to not to be involved in a former scientific study.
- •abnormal PFT (at least one value below the lower limit of normal)
- •Abnormal chest radiography
- •Abnormal ECG
排除标准
- •Chronic pathology
- •Long-standing treatments, recent vaccination (< 3 weeks), recent bronchitis (< 3 weeks)
- •Cardio-respiratory diseases, in particular: asthma, COPD, previous pneumothorax, hemoptyses, acute coronary syndrome, uncontrolled and/or untreated cardiac arrhythmia, bradycardia (<55bpm), arterial hypertension (diastolic>95mmHg, systolic>150mmHg),
- •Current abdominal disease (clinical or known hepatomegaly, irritable bowel syndrome, etc...), gastro-oesophageal reflux
- •BMI < 18 and > 26
- •Disorder of coagulation (and anticoagulant treatment), frequent epistaxis
- •Porphyrae
- •Epilepsy, Cerebrovascular accident (stroke or transient ischemic attack) < 3 months
- •Severe hepatic Insufficiency
- •Benign Prostatic Hypertrophy
- •Allergy: latex, lidocaine, salbutamol, ipratropium or parasympathomimetic agents
- •Current allergic rhino-conjunctivitis
- •History of previous oedema of Quincke or anaphylactic shock
- •Aneurism of the aorta, cerebral aneurism or another arterial aneurism
- •Myasthenia
- •Thyroid disorders
- •Protected underage child and adults
研究组 & 干预措施
drug
干预措施: Inhaled Bronchodilators +/- Inhaled Methacholine (Drug)
结局指标
主要结局
Occurrence or increase of the Expiratory Flow Limitation (EFL) under either Negative Expiratory Pressure (NEP) or submaximal gentle forced expiratory manoeuvres (partial flow-volume loops at tidal volume)
时间窗: After bronchodilation, up to 2 hours
The aim of this study is to evaluate the occurrence or increase of the Expiratory Flow Limitation (EFL) under either Negative Expiratory Pressure (NEP) or submaximal gentle forced expiratory manoeuvres (partial flow-volume loops at tidal volume) after bronchodilation in certain healthy men breathing at low pulmonary volumes (by applying a chest wall strapping).
次要结局
- Evaluation of the effect of the fall of the tonicity of the bronchial smooth muscles (normal and constrained pulmonary volumes) on the modifications of forced flow-volume loop(after bronchodilation while breathing at low pulmonary volumes (by applying a chest wall strapping), up to 2 hours)
- Evaluation of the effect of the fall of the tonicity of the bronchial smooth muscles (normal and constrained pulmonary volumes) on the inspiratory capacity airways resistances(after bronchodilation while breathing at low pulmonary volumes (by applying a chest wall strapping), up to 2 hours)
- Evaluation of the effect of the fall of the tonicity of the bronchial smooth muscles (normal and constrained pulmonary volumes) on the closing volume(after bronchodilation while breathing at low pulmonary volumes (by applying a chest wall strapping), up to 2 hours)