Topical lidocaine improves conditions for laryngeal mask airway insertion.
OBJECTIVE
We hypothesized that optimal laryngeal mask airway (LMA) insertion conditions might be achieved with topical lidocaine and a smaller dose of propofol. In this study, insertion conditions after topical lidocaine 40 mg followed by propofol 2 mg.kg(-1) were compared with propofol 2 mg.kg(-1) or propofol 3 mg.kg(-1) alone.


METHODS
Ninety patients were recruited for this randomized prospective double-blind study. One group received four sprays of topical lidocaine (40 mg) over the posterior pharyngeal wall followed by propofol 2 mg.kg(-1) (Group 2PL; n = 30). The other two groups received four sprays of 0.9% normal saline followed by propofol 2 mg.kg(-1) (Group 2P; n = 30) or by propofol 3 mg.kg(-1) (Group 3P; n = 30). The frequency of optimal insertion conditions (successful insertion at the first attempt without adverse responses) and side effects were recorded.


RESULTS
The frequency of optimal insertion conditions was greater in Group 2PL (20/30, 67%) and Group 3P (22/30, 73%) than in Group 2P (11/20, 37%) (P = 0.009). In Group 3P, the mean blood pressure was lower than in the other groups prior to LMA-Classic insertion (P = 0.003) but was similar after insertion. The incidence of apnea was greater in Group 3P patients (17/30, 57%) than in Group 2P (2/30, 7%) or Group 2PL patients (1/30, 3%) (P < 0.001).


CONCLUSIONS
Topical lidocaine 40 mg followed by propofol 2 mg.kg(-1) can provide optimal insertion conditions of the LMA-Classic comparable to those of propofol 3 mg.kg(-1), with fewer hemodynamic changes and a lower incidence of apnea.
Department of Anesthesiology, E-DA Hospital, I-Shou University, No.1, Yi-Da Road, Chia-Shu Tsuen, Yan-Chao Shiung, Kaohsiung, 824, Taiwan.
Chih-Fang
CF
Changchien
Hung-Shu
HS
Chen
Shao-Wei
SW
Hsieh
Ping-Heng
PH
Tan
Victor Chia-Hsiang
VC
Lin
Chien-Cheng
CC
Liu
Ping-Hsin
PH
Liu
Kuo-Chuan
KC
Hung
D000287:Administration, Topical; D000328:Adult; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D001049:Apnea / Q000139:chemically induced; D001794:Blood Pressure / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D017214:Laryngeal Masks; D008012:Lidocaine / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D015742:Propofol / Q000008:administration & dosage / Q000009:adverse effects; D011446:Prospective Studies
D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D008012:Lidocaine; D015742:Propofol