Which of the following is a true statement about the delivery of warm, humidified gas to the lungs?

a. The gas delivered to the nose or mouth contains 95% relative humidity and has an absolute humidity of 28 mg/L to 34 mg/L at 29° C to 32° C.
b. The gas delivered to the hypopharynx contains 50% relative humidity and has an absolute humidity level of 10 mg/L at 22° C.
c. The gas delivered to the midtrachea con-tains 50% relative humidity and has an absolute humidity level of 36 mg/L to 40 mg/L at 31° C to 35° C.
d. The gas delivered to the midtrachea con-tains 100% relative humidity and has an absolute humidity level of 36 mg/L to 40 mg/L at 31° C to 35° C.

ANS: D
The gas delivered to the midtrachea contains 100% relative humidity and has an absolute humid-ity level of 36 mg/L to 40 mg/L at 31° C to 35° C. The gas delivered to the hypopharynx contains 95% relative humidity and has an absolute humidity level of 28 mg/L to 34 mg/L at 29° C to 32° C. The gas delivered to the nose or mouth contains 50% relative humidity and has an absolute humidity level of 10 mg/L at 22° C. See Box 6-3.