Monday February 16, 2009

Q: How supplemental oxygen helps in accelerating the resolution of a pneumothorax?


Answer: oxygen may speed resolution of the pneumothorax by increasing the gradient for nitrogen absorption. Resolution of pneumothorax has shown increase rate of absorption if oxygen supplement is increased from a lower concentration via nasal cannula to a partial rebreathing mask. Oxygen therapy results in a fourfold increase in the mean rate of absorption. This fact is known since last 40 years and still applicable and easy to do 1. During inhalation of room air the total gas pressure in blood from the distal end of a capillary is about 706 mm Hg, whereas during inhalation of 100% oxygen it is about 146 mm Hg. This difference is mainly due to a reduction in partial pressure of nitrogen from 573 mm Hg to a zero - and can be accompanied by an increase in the partial pressure of oxygen in arterial blood from 100 to 640 mm Hg. oxygen utilization in the tissues ensures that the partial pressure of oxygen in end-capillary blood rises only slightly from 40 mm Hg to about 53 mm Hg.

Pneumothorax during needle lung biopsy can be prevented by breathing 100% oxygen 2.



References: click to get article

1. Oxygen Therapy for Spontaneous Pneumothorax - Br Med J. 1971 October 9; 4(5779): 86–88.
2. Prevention of pneumothorax in needle lung biopsy by breathing 100% oxygen - Thorax. 1980 January; 35(1): 37–41.