Background and objective: To assess incidence and intensity of pain on intravenous injection of propofol (CAS 2078-548) in an emulsion of medium-chain/long-chain triglycerides (MCT/LCT, 50:50) in patients undergoing different elective surgical interventions.
Methods: The new solvent was used for induction of general anesthesia. Spontaneous pain reactions and pain elicited upon questioning were assessed. Patients were asked to grade the pain as mild, moderate or severe. Co-medication with sedative or analgesic drugs, size of the intravenous cannulae, site of injection and administration as a single bolus or in divided doses were recorded.
Results: Overall incidence of pain was 28.4% (390 out of 1375 patients). Twelve percent of the patients complained spontaneously and 16.4% reported pain after questioning. Pain intensity was graded as mild by 16.7% of the patients. The incidence of pain was significantly less when using an antecubital vein compared with a forearm or dorsal hand vein (p = 0.017 spontaneously reported pain, p = 0.001 pain elicited upon questioning). The number of patients complaining spontaneously of pain was significantly lower (p = 0.006) for large size than for small and medium size cannulae.
Conclusions: The incidence of pain on injection of a medium-/long-chain triglyceride propofol formulation was 28.4% with 16.7% of the patients reporting mild pain. The use of an antecubital vein or a large size venous cannula appears to reduce the injection pain.