Final answer:
The nurse's instruction on incentive spirometry represents the implementation phase. This phase involves executing the patient's care plan, where spirometry can help improve lung function and diagnose respiratory conditions.
Step-by-step explanation:
The nurse instructs the patient about incentive spirometry as preoperative teaching which illustrates the implementation phase of the nursing process. During this phase, nurses carry out the care plan that was prepared for the patient. Incentive spirometry is a respiratory therapy that assists patients in deep breathing to prevent pulmonary complications after surgery. The device helps patients improve the functioning of their lungs and can also be used to measure lung function, which can be crucial for diagnosing conditions that cause a decrease in the capacity of the lungs to hold air. Additionally, spirometry results can be used to diagnose respiratory diseases or determine the effectiveness of disease treatment by looking at changes in lung volumes over time.