To O2 or no to O2 (in stable pneumothorax?)

by Adam Herbstritt

A 40yr male presents after a high fall off a ladder. With significant tenderness down his left chest into flank he gets a trauma CT, revealing a couple of rib fractures and a moderate left sided pneumothorax.

Discussion with cardiothoracics agrees a plan for admission for observation but no drain. Analgesia is optimised.

Is there anything else we should be doing to speed resolution of the pneumo?

Well it was news to me that giving O2 via face mask speeds pneumo resolution.  Its certainly in the BTS guidelines as suggested management for all hospitalised spontaneous pneumo's (I havn't been giving it here either) quoting "a fourfold increase in the rate of pneumothorax resolution".

What's best practice?
A quick-ish pubmed search reveals sparse data.  The BTS guidelines only reference their statement with 2 papers -  one study from the 1970's (of 20 patients) and one 'postiive' rabbit model.  A 2010 Bestbets suggests we shouldn't be giving O2 unless hypoxic. Some recent neonatal cohorts here and here (approx 160 patients) found no benefit to high / moderate / or no supplemental O2 in time to resolution.  Increasing data has demonstrated the potential harms from hypERoxia that extends significantly beyond the obvious patient discomfort and inconvenience. 

Bottom line; Avoid supplemental O2 in pneumothorax unless hypoxic - minimal supportive evidence with known potential harms. 

Think differently? Comments welcomed!