COMPARISON BETWEEN THE EFFICACY OF TRAPEZIUS SQUEEZING TEST AND JAW THRUST MANEUVER FOR PREDICTION OF SUCCESSFUL INSERTION OF LARYNGEAL MASK AIRWAY

The aim of this study was to compare trapezius squeezing and jaw thrust to
evaluate suitable conditions for laryngeal mask airway (LMA) insertion.
Materials & Methods: In this clinical trial study, 138 patients with ASA physical status 1 or 2 who were
candidates for elective surgery of shin fracture were randomly assigned into one of the groups of
trapezius squeeze and raising the lower jaw maneuvers. In both groups, no motor response to the
maneuver was considered as the suitable time for LMA insertion. Laryngospasm, coughing, gag reflex,
breath-holding, oxygen saturation of less than 90%, and the presence of purposeful movements during
LMA insertion and up to one minute after that were considered as unsuccessful attempts in LMA
insertion. The mean blood pressure, heart rate, LMA insertion time and the incidence of successful LMA
insertion in both groups were compared.
Results: The incidence of successful LMA insertion in the trapezius squeezing group (94.2%) and the
lower jaw thrust (98.6%) did not have any significant difference (p=0.18). The average time for LMA
insertion from initiation of induction was significantly longer in the patients with trapezius squeezing
than in patients with lower jaw thrust maneuver (p<0. 001). The vital signs (including blood pressure
and heart rate) of the patients in the groups were not different after LMA insertion (p>0.05).
Conclusion: Trapezius squeezing and jaw thrust in patients undergoing anesthesia by propofol as a
prediction index for successful LMA insertion have no superiority over each other