Lung expansion methods that increase the transpulmonary pressure gradients by increasing alve-olar pressure include which of the following?

1. Incentive spirometry (IS)
2. Positive end-expiration pressure therapy
3. Intermittent positive-pressure breathing (IPPB)
4. Expiratory positive airway pressure (EPAP)
a. 1 and 2 only
b. 2, 3, and 4 only
c. 1 and 3 only
d. 1, 2, 3, and 4

ANS: B
Positive-pressure lung expansion therapies may apply pressure during inspiration only (as in IPPB), during expiration only (as in positive expiratory pressure [PEP] and EPAP), or during both inspiration and expiration (CPAP).