Final answer:
When a client who has received moderate (conscious) sedation suddenly becomes restless and lightheaded, the nurse should stop the procedure and call the healthcare provider.
Step-by-step explanation:
When a client who has received moderate (conscious) sedation suddenly becomes restless and reports feeling lightheaded, the nurse should take the following action:
d. Stop the procedure and call the healthcare provider.
This sudden change in behavior and symptoms may indicate a potentially serious reaction to the sedation. It is important to stop the procedure and notify the healthcare provider immediately to ensure prompt assessment and appropriate intervention.