Final answer:
A nurse should follow up on a temperature of 38.6°C, O² saturation of 85%, and crackles in the left upper lobe in a COPD patient, as they may indicate infection, hypoxemia, and potential respiratory complications needing intervention.
Step-by-step explanation:
A nurse caring for a client with COPD should follow up on certain clinical findings due to their potential significance in the patient's condition. Among the findings listed, three that require immediate follow-up are: a temperature of 38.6°C (101.5°F), O² saturation of 85% on room air, and crackles heard in the left upper lobe. Elevated temperature may indicate a possible infection or exacerbation of COPD. An O² saturation below the normal range (which is typically 95-100%) suggests that the patient is experiencing significant hypoxemia and may need supplemental oxygen. Lastly, crackles in the lung could be a sign of pneumonia or other respiratory complications that may need to be addressed with further diagnostic testing or treatment adjustments.