Randomized double-blind comparison of ketamine-propofol and fentanyl-propofol for the insertion of laryngeal mask airway in children

Abstract

Till date, different combinations of adjuncts with induction agents have been tried for Laryngeal Mask Airway (LMA) insertion; yet, the ideal combination that provides the best insertion conditions with minimal side effects has not been identified, particularly in children. PATIENTS #ENTITYSTARTX00026; Hundred paediatric ASA grade I and II patients, aged 3-12 years, were randomly allocated to receive intravenously either fentanyl 2μg kg(-1) (Group F, n=50) or ketamine 0.5 mg kg(-1) (Group K, n=50), before induction of anaesthesia with propofol 3.5 mg kg(-1). Arterial blood pressure and heart rate were measured before induction (baseline), immediately before induction, immediately before LMA insertion, and at 1, 3 and 5 minutes after LMA insertion. Following LMA insertion, the following six subjective endpoints were graded by a blinded anaesthetist using ordinal scales graded 1 to 3: mouth opening, gagging, swallowing, head and limb movements, laryngospasm and resistance to insertion. Duration and incidence of apnoea was also recorded. The incidence of resistance to mouth opening, resistance to LMA insertion and incidence of swallowing was not statistically significant between the two groups. Coughing/ gagging was seen in 8% patients in group K as compared to 28% patients in group K. Limb/ head movements were observed in 64% patients in the fentanyl group and in 76% patients in the ketamine group. Laryngospasm was not seen in any patient in either group. Incidence of apnoea was 80% in the fentanyl group and 50% in the ketamine group. The heart rate, systolic blood pressure, diastolic blood pressure and mean arterial pressure were consistently higher in the ketamine group as compared to the fentanyl group. The combination of fentanyl (2μg kg-1) and propofol (3.5mg kg-1) provides better conditions for LMA insertion in children than a combination of ketamine (0.5 mg kg-1) and propofol (3.5mg kg-1).