Work Step by Step
Pneumothorax - it is the presence of air in pleural sac leading to lung collapse . - if unilateral, hypoxia does not occur because the the healthy lung will be enough. - also, all the cardiac output from the right ventricle is shifted to the normal lung. - Bilateral Pneumothorax ( = on both sides ) is fatal. # Types of Pnumothorax : 1) Closed : - where a communication between the pleura and atmosphere or lung is closed. - and air in the pleura is gradually absorbed and lung re-expand. - the intrapleural pressure is negative. 2) Open : - where the pleural sac communicates with the atmosphere through a wound in the chest wall or through a bronchus - collapse. - the intrapleural pressure is zero ( = atmosphere ). 3) Valvular : - where the opening between pleura and lung acts as one-way valve allowing air to enter the pleura during inspiration but prevents its escape during expiration. -the intrapleural pressure becomes positive. 4) Artificial : - where air is injected into the pleural sac to cause collapse of one lung. - it may be used for treatment of tuberculosis ( TB).