Caffeine supplementation as part of enhanced recovery after surgery pathways: a narrative review of the evidence and knowledge gaps.

Caffeine is used daily by 85% of United States adults and caffeine withdrawal is a major cause of perioperative headache. Studies have shown that caffeine supplementation in chronic caffeinators reduces the incidence of perioperative headache. This narrative review discusses the perioperative implications of caffeine withdrawal and outlines the benefits of and strategies of caffeine supplementation in the perioperative period. It is time to "wake up and smell the coffee" on integration of caffeine into established enhanced recovery after surgery protocols as a mechanism to consistently provide perioperative caffeine replacement.