A Novel Two-Step Dosing Induction Strategy (The Propofol Challenge Test) to Minimize Propofol Injection Pain

Propofol is the most widely used intravenous hypnotic agent for the induction of general anesthesia owing to its rapid onset and short duration of action. Despite its favorable pharmacokinetics and widespread use, a notable drawback persists: the incidence of pain on injection. Statistics on the matter are widely variable, but some estimates indicate that the incidence of pain with propofol injection is around 70%1. To date, no studies have systematically evaluated whether dividing the induction dose of propofol-starting with a small sub-induction bolus (e.g., 20 mg) followed by the remainder-can reduce pain perception. We hypothesize that a two-step administration of propofol-consisting of a small initial dose followed by the remaining dose-may serve as a nociceptive preconditioning stimulus and reduce postoperative patient-recalled injection pain compared to standard single-bolus administration.