Yes, good point! Based on the Cochrane review, we could confidently say nitrous oxide has an effect on pain. I should have said the evidence for the degree of pain relief appears variable and uncertain, although on a closer look, Cochrane's estimate suggests 3.5 on a 0-10 scale vs placebo (which is pretty great).
Hi Julia, thanks for drawing our attention to this! No, we didn’t look into it. From a quick review of the evidence, the effectiveness appears variable and uncertain. But as you rightly point out, it doesn't require an anaesthetist, and it could therefore play an important role in a low resource setting.