Final answer:
The nurse should ask a family member to sit with the client, as this respects the family's request and the health care provider's decision against sedation and restraints, while ensuring patient safety.
Step-by-step explanation:
The most appropriate action by the nurse, when caring for a client with a head injury who is restless and pulling at the intravenous line, is to ask a family member to sit with the client. This approach respects the family's request for no restraints and the health care provider's decision to avoid sedation. Family involvement often has a calming effect on the patient, and the familial presence can aid in monitoring and ensuring the safety of the IV line and the patient overall. If a family member is unavailable or unable to fulfill this role, the nurse should then confer with the nurse manager or look into other patient-focused care options that align with the wishes of the client and family.