For 30 kg adult the size of laryngeal mask airway most appropriate is:-
High-Yield Explanation
LMA Sizing LMA Size Patient Size 1 Neonate / Infants < 5kg 1 1/2 Infants 5-10 kg 2 Infants / Children 10-20 kg 2 1/2 Children 20-30 kg 3 Children / Small adults 30-50 kg 4 Adults 50-70 kg 5 Large adult > 70 kg The largest possible size that will fit comfoably in the oral cavity should be chosen.