Final answer:
The nurse should first assess and maintain pressure bandages on the affected leg for a client who is 6 hours postoperative vein ligation with varicose veins.
Step-by-step explanation:
The nursing intervention that the nurse should implement first for a client who is 6 hours postoperative vein ligation and has varicose veins is b. Assess and maintain pressure bandages on the affected leg. Assessing and maintaining pressure bandages on the affected leg is important to control bleeding and promote healing. Dangling the legs off the side of the bed can be done after the bandages are properly assessed and applied.