European Journal of Anaesthesiology



Original Article

Nitrous oxide/oxygen mixture and the prevention of pain during injection of propofol


D. Harmon a1c1, C. Rozario a1 and D. Lowe a1
a1 University College Hospital, Department of Anaesthesia, Galway, Ireland

Article author query
harmon d   [PubMed][Google Scholar] 
rozario c   [PubMed][Google Scholar] 
lowe d   [PubMed][Google Scholar] 

Summary

Background and objective: The incidence of pain associated with the injection of propofol still remains a problem. This study sought to examine the analgesic effects of inhaled nitrous oxide in oxygen on the prevention of propofol injection pain.

Methods: Nitrous oxide in oxygen was compared with a lidocaine (20 mg)–propofol mixture and with propofol alone (control) in a prospective, randomized, observer-blinded study. ASA I and II patients (n = 135) scheduled for elective surgical procedures were studied. A standard propofol injection technique and scoring system to measure the pain on injection was used.

Results: Demographic variables were similar between the study groups. Without analgesia (control) 26 of 45 patients (58%) reported pain on injection compared with 11 of 45 patients (24%) in both the nitrous oxide (95% CI: 14–52%, P = 0.001) and lidocaine groups (95% CI: 14–52%, P = 0.001).

Conclusions: The inhalation of a nitrous oxide/oxygen mixture significantly reduces the incidence of pain during propofol injection. This therapeutic stratagem was as effective as a lidocaine–propofol mixture.

(Accepted April 2002)


Key Words: ANAESTHETICS, INTRAVENOUS, propofol; ANAESTHETICS, LOCAL, lidocaine; INORGANIC CHEMICALS, nitrous oxide; NERVOUS SYSTEM PHYSIOLOGY, SENSATION, pain; PERIPHERAL NERVOUS SYSTEM AGENTS, SENSORY SYSTEM AGENTS.

Correspondence:
c1 Correspondence to: Dominic Harmon, Department of Anaesthesia and Intensive Care Medicine, Cork University Hospital, Wilton Road, Cork, Ireland. E-mail: [email protected]; Tel: + 353 21 4546400; Fax: + 353 21 4546434