COMPARISON OF PROPOFOL VERSUS THIOPENTONE WITH MIDAZOLAM OR LIDOCAINETO FACILITATE LARYNGEAL MASK INSERTION

Purpose: To assess the ease of insertion of laryngeal mask airway (LMA ) comparing propofol with lidocaine or midazolam followed by thiopento ne and compare the costs with each technique. Methods: One hundred and fifty ASA 1 or 2 patients equally divided into three groups scheduled for elective surgery were recruited into this prospective, single bli nd, randomized parallel groups study. Anaesthetic induction was achiev ed with 1 mu g . kg(-1) fentanyl iv followed by either 2.5 mg . kg(-1) propofol (group P), or a sequence of 1.5 mg . kg(-1) lidocaine and 5 mg . kg(-1) thiopentone (group LT), or midazolam 0.1 mg . kg(-1) and, three minutes later, 5 mg . kg(-1) thiopentone (group MT). The LMA was inserted by the blinded anaesthetist who assessed and graded the cond itions for LMA insertion and noted any adverse responses (i.e., inadeq uate jaw relaxation, gagging, coughing, limb or head movement, hiccoug h and laryngospasm). Conditions were considered ''excellent'' if there were no adverse responses, and ''satisfactory'' if such a response wa s mild and transient. Results: Excellent or satisfactory conditions we re observed in 48 (96%) patients in the midazolam-thiopentone group, 4 6 (92%) in the propofol group, and 34 (68%) in the lidocaine-thiopento ne group (P=0.0001). The incidence of gagging (P=0.042), limb movement (P=0.031), and laryngospasm (P=0.0001) was higher in the lidocaine-th iopentone group. Conclusions: With the above doses, a fentanyl-midazol am-thiopentone combination which is about 35% less expensive than fent anyl-propofol, provides equally good conditions for the insertion of L MA.