Berry et al developed an algorithm to help use the proper size of laryngeal mask airway (LMA) in an adult. This may be effective than using weight-based criteria alone. The authors are from Nambour General Hospital and the University of Queensland in Australia.


Initial Selection

Size #4

Size #5




body weight


> 45 kilograms


< 165 cm

>= 165 cm

from Figure 1, page 570



• I am not sure if this algorithm would work in the elderly. The oldest patient in the study was 68 years old.


After proper insertion into the patient, inflate the cuff with 7-10 mL of air.


If the oropharyngeal leak pressure (OLP) is >= 15 cm H2O then the seal is adequate.


If the oropharyngeal leak pressure is < 15 cm H20, then trying the following interventions:

(1) add an additional 5-10 mL to the cuff

(2) increase the size of the LMA and repeat cuff inflation (a size #6 may be appropriate for large males)

(3) apply anterior neck pressure then release


If none of these is successful in increasing the OLP to >= 15 cm, then consider an alternative airway.


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