Laryngeal Mask Insertion Conditions And Hemodynamic Effects

This study aims to compare two anesthesia protocols: propofol induction with or without a prior injection of ketamine, in term of LMA insertion conditions(favorable= satisfactory or unfavorable= unsatisfactory ) and hemodynamic effects (decrease of 20 % from baseline of blood pressure and heart rate).

The conditions of LMA insertion have been assessed in each study group by an experimented anesthesiologist, who was unaware of the treatment group assignment. Conditions were considered satisfactory, if the 4 following criteria were acceptable: the jaw was relaxed, there was no coughing, swallowing and no limb movement, and then the LMA was inserted. When the investigators save at least one unacceptable of these criteria, conditions were considered to be unsatisfactory and thereafter anesthesia was deepened with supplemental dose of propofol 1mg.kg-¹ and 1 minute later a reinsertion was attempted. The total number of attempts at LMA insertion was recorded. Children trachea was intubated after 3 failed attempts of LMA insertion, and then patient was excluded.

Inclusion criteria

• ASA physical status I or II who were scheduled to minor elective ambulatory surgery (e.g. inguinal hernia, undescended testes, umbilical hernia) performed by experienced surgeon under general anesthesia.

Exclusion criteria

• patients with full stomach
• A history of gastric reflux
• A history of convulsions, cardiovascular or neuromuscular disease
• Allergies to the study drugs
• obese children
• suspected difficult airway and hyper-reactive airway disease