الفهرس 
PHYSIOLOGICAL CONSIDERATIONSOnly 14 pages are availabe for public view
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Abstract
PULMONARY BARQTRAUMA
Pulmonary barotrauma is defined as extra-alveolar air, (EAA) r from lung damage secondary to changes in intrathoracic pressure. EAA is known as air rupturing from the respiratory tract to the surrounding tissue spaces, usually during the ventilatcry therapy.
During normal breathing, inspiration is an active process while expiration is passive in the sense that no muscles which decrease the intrathoracic volume contract. The pressure gradient developed during inflation and deflation of the thorax overcomes two types of resistance; elastic and noneiastic. If a pressure gradient develops between the alveoli and the perivascular sheaths, alveolar rupture results and EAA is formed.
At first EAA presents as pulmonary interstitial emphysema, then it follows the path of least resistance forming pneuniomediast inum- from the mediastinum, air can reach the pleural cavity, peritoneal cavity, retrcperitoneal space, or dissects subcutaneously resulting in pneumothorax, pneumoperitoneum or subcutaneous emphysema respectively.
Ventilator-related pulmonary barotrauma probably occurs
in 3-7% of all patients requiring mechanical ventilation. The proposed risk factors for pulmonary barotrauma in