Clinical scenario

A 73 year old woman presents to the emergency department with a six hour history of left sided hemiparesis. She has a past history of hypertension. On examination she is GCS 15 with a dense left hemiparesis and her basic observations are stable. You wonder whether the use of supplemental oxygen in the acute stage is needed and will have any effect on long term prognosis.

Three part question

In a [patient presenting to the emergency department with a stroke who does not need resuscitative measures] is [supplemental oxygen better than no oxygen] at [reducing long term disability and mortality]?

Search strategy

Medline 1966-07/03 using the OVID interface. [exp cerebrovascular accident OR cerebrovacsular.mp OR stroke.mp] AND [exp oxygen OR exp oxygen inhalation therapy OR oxygen.mp] AND [exp disability evaluation OR disability.mp] LIMIT to human AND English.

Search outcome

Altogether 18 papers were found of which one directly addressed the three part question (table 1).

Comment(s)

This large, well conducted study shows no statistically significant difference between the two groups. It shows there is no benefit to giving oxygen routinely to stroke patients, and suggests if given to non-hypoxic patients with mild to moderate strokes may infact increase mortality. The results for severe stroke patients were inconclusive.

The authors hypothesise (based on a small number of animal studies) that this may be attributable to oxygen free radicals.

CLINICAL BOTTOM LINE

In non-hypoxic patients with minor or moderate strokes supplemental oxygen is of no clinical benefit.