Which of the following nursing interventions should have the highest priority during the first hour after the admission of a client with cholecystitis who is experiencing pain, nausea, and vomiting?

The correct answer is A: Administering pain medication. Immediate pain relief is crucial in managing cholecystitis symptoms and improving the client's comfort. Pain can lead to increased stress, anxiety, and physiological responses that can worsen the condition. Administering pain medication promptly can help alleviate these symptoms and allow the client to rest. Completing the admission history (B) is important but can be done after addressing the urgent pain and discomfort. Maintaining hydration (C) is also essential but may not be the highest priority compared to pain relief. Teaching about planned diagnostic tests (D) is important for the client's understanding but can be deferred until the pain and discomfort are managed effectively.