We, the investigators at Queen's University, propose to conduct a randomized, double-blind, feasibility trial comparing low-dose ketamine versus fentanyl as adjuncts to Emergency Department procedural sedation with propofol. The outcomes of interest will be safety, with respect to hemodynamic and respiratory adverse effects, as well as efficacy, with respect to adequacy of sedation and analgesia, recovery profiles and patient/physician satisfaction. Our hypothesis, based on a review of existing anesthesia literature, is that low-dose ketamine may be a safer and more efficacious alternative to fentanyl when used as an adjunct to propofol-assisted procedural sedation.