1)central airway obstruction: above the forfication (between the glottis and the carina) obstruction locates out of thorax( paralysis, edema or inflammation of vocal cords inspiratory dyspnea obstruction locates within thorax expiratory dyspnea W
17 above the forfication (between the glottis and the carina) obstruction locates out of thorax（ paralysis, edema or inflammation of vocal cords ） inspiratory dyspnea obstruction locates within thorax expiratory dyspnea why? 1) central airway obstruction:
Phase of Phase of Phase of Phase of expiration Inspiration expiration inspiration (Ptr>Patm)(Ptr<Patm) (Ptr<Pp) (Ptr>Pp) Patm 面产亮 因除的 呼气 吸气 呼气吸气 图151不同部位气道阻塞呼吸困难的特征 The effects on the phase of The effects on the phase of respiration on an extrathoracic respiration on an intrathoracic variable obstruction variable obstruction Ptr--intratrachel pressure Ppl--pleural pressul Patm-atmospheric pressure
18 Phase of expiration (Ptr > Patm) Phase of inspiration (Ptr <Patm) Phase of inspiration (Ptr>Ppl) Phase of expiration (Ptr<Ppl) The effects on the phase of respiration on an extrathoracic variable obstruction The effects on the phase of respiration on an intrathoracic variable obstruction Ptr—intratrachel pressure Ppl—pleural pressure Patm—atmospheric pressure Ptr Patm Ptr Patm Ptr Ptr Ppl Ppl
2) peripheral airway obstruction(diameter <2mm) Alveolar duct Alveoli Respiratory Alveolar duct bronchioles Terminal bronchiole Alveolar sac peripheral airway character e Wall: thin, without cartilage support a Diameter changes with respiration Alveolar duct a keep tight connection to Alveolus surrounding alveoli
19 peripheral airway character： Wall: thin,without cartilage support； Diameter changes with respiration； keep tight connection to surrounding alveoli 2) peripheral airway obstruction (diameter <2mm）:
causes and mechanism chronic obstructive pulmonary disease (chronic bronchitis, emphysema ) severe pneumonia, atelectasis etc equal pressure point is moved up → expiratory dyspnea
20 causes and mechanism: chronic obstructive pulmonary disease (chronic bronchitis，emphysema ), severe pneumonia, atelectasis ,etc. → equal pressure point is moved up expiratory dyspnea
Intra-airway pressure extra-airway pressure Equal pressure point+5 +2Q +20H30+20 +20 +20 H+20 +35 25 +20 +20 +20 +20 normal person makes Emphysema patients makes forced expiration forced expiration
21 Equal pressure point normal person makes forced expiration Emphysema patients makes forced expiration point that Intra-airway pressure = extra-airway pressure