Final answer:
An incentive spirometer is used to encourage postoperative deep breathing, which helps to increase lung volume and decrease the work of breathing by providing feedback on inspiratory volume.
Step-by-step explanation:
To encourage postoperative deep breathing, the tool that can be used is an incentive spirometer. An incentive spirometer is a medical device used to help patients improve the functioning of their lungs. It is particularly beneficial after surgery or during treatment for lung conditions. It encourages voluntary deep breathing by providing visual feedback to patients about inspiratory volume. The device aids in the prevention of pulmonary complications, such as pneumonia, and is designed to increase lung volume and decrease the work of breathing.
The other options listed serve different functions: Patient-controlled analgesia is a method of pain management, narcotic analgesics are drugs used to reduce pain, and continuous positive airway pressure (CPAP) is a treatment most commonly used for conditions like sleep apnea, where it helps to keep the airway open during sleep.