Final answer:
To prevent atelectasis and pneumonia, the nurse should teach the patient deep breathing and coughing exercises, and emphasize good oral hygiene and handwashing to reduce infection risk.
Step-by-step explanation:
To prevent atelectasis and pneumonia, the nurse should encourage the patient to practice deep breathing and coughing exercises. Deep breathing exercises help to expand the lungs and improve air exchange, while coughing helps to clear mucus and prevent airway obstruction. In addition, the nurse should also encourage the patient to maintain good oral hygiene and practice proper handwashing techniques to reduce the risk of infection.