2. Obstructive hypoventilation central airway obstruction peripheral airway obstruction
16 2. Obstructive hypoventilation : central airway obstruction peripheral airway obstruction
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 why?
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>Ppl) 是景 Patm Patm Ppl 因 图151不同部位气道阻塞呼吸困难的特征零气 呼气溶/吸气 呼气 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 pressure 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 B Diameter changes with respiration Alveolar duct 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