Lung collapse

The entry of air into the pleural cavity is referred to as a pneumothorax. This may occur spontaneously when a "leak" develops on the surface of the lung, allowing air to escape from the airways into pleural space. It may also result from a physical trauma that causes penetration of the chest wall so that air enters pleural space from the atmosphere. In either case, the pleural cavity is no longer a closed space and the pressure within it equilibrates with the atmospheric pressure (0 cmH20). As a result, the transpulmonary pressure is also equal to 0 cmH20 and the lung collapses. 

Atelectasis is defined as a condition in which part of a lung or a whole lung collapses and alveoli completely deflate. 

Pleural membranes cover the lung and must be intact to allow the lung to inflate. If the chest wall is injured and the pleura punctured, air enters the pleural cavity (pneumothorax) and the lung collapses. 

Lung collapse (atelectasis) reduces FEVi and is likely to affect blood gas tensions, reducing arterial P02. 

Respiratory distress syndrome is a pathological condition resulting from a failure in the biosynthetic pathway for dipalmitoyl phosphatidyl choline. This phospholipid, in conjunction with specific proteins and other phospholipids, is found in the extracellular fluid that surrounds the alveoli of the lung, where it decreases the surface tension of the fluid to prevent lung collapse at the end of the expiration phase of breathing. Premature infants may suffer from respiratory distress syndrome because their immature lungs do not synthesize enough dipalmitoyl phosphatidyl choline. 

He was devastated to find out that he had cancer of the lung. He had lost the other lung as a child. He was having recurrent lung collapse (called pneumothorax), so the lung was partially surgically removed. There s... 

Aslani J, Ghanei M. A case of unilateral lung collapse in a mustard gas victim. Military Medicine Journal. 1998 l(l 2) 49-50)... 

Pulmonary surfactant is present in alveolar spaces to lower surface tension and prevent lung collapse during exhalation. This surfactant is a lipoprotein with about 75% of the lipid content being phospholipid. About 75% of this phospholipid is phosphatidyl choline with Qg hydrocarbon chains being most predominant. 

Ding Y, White PE. Lung collapse after induction of anesthesia in a healthy outpatient. Anesthesiology 1994 80 689-690. 

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