Lidocaine given intravenously improves conditions for laryngeal mask airway insertion during propofol target-controlled infusion.
OBJECTIVE
Patient response to laryngeal mask airway insertion during propofol induction depends on many factors. Lidocaine has been used to reduce cardiovascular responses, coughing, and bucking induced by tracheal intubation. The aim of this study was to determine the effects of intravenous lidocaine on laryngeal mask airway insertion conditions during the induction of anaesthesia with propofol target-controlled infusion.


METHODS
Eighty patients, 16-54 years of age, weighing between 45 and 100 kg, who underwent minor surgery, were randomly divided into two groups (the lidocaine and control groups). Anaesthesia was induced with propofol target-controlled infusion at a target plasma concentration of 6 microg ml. The lidocaine group received 1.5 mg kg of lidocaine 50 s after starting target-controlled infusion and the control group received an equivalent volume of saline. Laryngeal mask airways were inserted when propofol effect-site concentrations reached 2.5 microg ml. Laryngeal mask airway insertion conditions (mouth opening, gagging, coughing, movements, laryngospasm, overall ease of insertion, and hiccups) were assessed, and haemodynamic responses were monitored for 3 min after laryngeal mask airway insertion.


RESULTS
No significant differences were observed between the two groups in terms of haemodynamic responses. However, the lidocaine group showed lower incidences of coughing (5 vs. 22.5%), gagging (25 vs. 55%), and laryngospasm (2.5 vs. 17.5%) (P < 0.05).


CONCLUSIONS
Pretreatment with intravenous lidocaine 1.5 mg kg during induction with propofol target-controlled infusion improves laryngeal mask airway insertion conditions.
Baik
Hee Jung
HJ
Department of Anaesthesiology, School of Medicine, Ewha Womans University, Seoul, Republic of Korea.
Kim
Youn Jin
YJ
Kim
Jong Hak
JH
D000293:Adolescent; D000328:Adult; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000493:pharmacokinetics; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D007442:Intubation, Intratracheal / Q000009:adverse effects / Q000379:methods*; D017214:Laryngeal Masks; D008012:Lidocaine / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D015742:Propofol / Q000008:administration & dosage* / Q000493:pharmacokinetics; D016037:Single-Blind Method; D055815:Young Adult
D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D008012:Lidocaine; D015742:Propofol