Final answer:
The nurse should reassure the client and adjust the traction first.
Step-by-step explanation:
The nurse should take the action of reassuring the client and adjusting the traction first.
Intermittent muscle spasms are a common side effect of skeletal traction and can be managed by adjusting the traction and providing reassurance to the client. Muscle relaxant medications may be used if the spasms persist or are severe, but they should not be the first action taken. Heat therapy and elevation of the affected extremity are not the appropriate interventions for muscle spasms in this situation.