Pain on propofol injection: Causes and remedies

Pain on propofol injection (POPI) is a minor problem that all anesthetists face every day. Introduction of several new formulations and hundreds of clinical trials have failed to find its remedy with just one intervention in all patients. This article highlights the causes of POPI and interventions that are used to eliminate this pain in current practice. Relevant articles from Medline and Embase databases were searched and included in this descriptive review with the following conclusions: (1) POPI is due to irritation of venous adventitia leading to release of mediators such as kininogen from kinin cascade. (2) When two or more drugs or measures are used, the incidence of POPI decreases considerably. Hence, the approach to eliminating POPI should be multimodal. (3) Any regimen that includes a drug having local anesthetic effect combined with central sedative/analgesic and rapid injection into a large vein should definitely reduce the risk of POPI to negligible levels.

Sevoflurane to alleviate pain on propofol injection

PURPOSE

Since the introduction of propofol, several drugs and methods have been used to alleviate the pain on its injection. This study was designed to evaluate the effect of adding sevoflurane 3% during preoxygenation in alleviation of pain on propofol injection.

METHODS

In this randomized single-blinded study, 100 patients were randomly allocated equally into five groups: sevoflurane-lidocaine-tourniquet (SLT), sevoflurane-lidocaine (SL), lidocaine-tourniquet (LT), lidocaine (L), and sevoflurane (S). Approximately 10 min before the induction of anesthesia, midazolam 1-2 mg was administered intravenously to all patients. All patients received fentanyl 1 µg/kg as pretreatment and a full induction dose of propofol. A blinded anesthesia nurse assessed pain and hand movements throughout the injection of propofol.

RESULTS

In the SLT group, all patients (100%) were pain free and had no hand movements. There was no significant difference in pain grade or in hand movements between the L and the S groups, or between the SLT and the SL groups. However, significant differences were observed in pain grade between the SLT and the L groups as well as between the SLT and the S groups. In addition, a significant difference in hand movement was observed only between the SLT and the S groups.

CONCLUSION

The addition of 3% sevoflurane at the time of preoxygenation for 1 min along with routine use of lidocaine-tourniquet completely prevented pain upon propofol injection, whereas sevoflurane by itself provided similar analgesia to premixed lidocaine with propofol.