The statement that is true concerning reservoir cannulas is which of the following?

a. The mustache cannula can hold about 40 mL of gas.
b. The pendant cannula can reduce oxygen supply use by 75%.
c. Patients prefer the mustache cannula to the pendant cannula.
d. Pendant cannulas can be concealed by the patient's clothing.

ANS: D
Studies indicate that mustache and pendant systems may reduce oxygen supply use by 50%. Many patients feel that mustache cannulas are heavier, larger, and more obvious. Pendant cannu-las can be concealed by the patient's clothing.