The nurse is monitoring a client with Cushing's disease in the postanesthesia care unit (PACU) after a hypophysectomy. Which intervention is most important for the nurse to include in the client's plan of care?

A. Maintaining nasal packing may be important post-hypophysectomy to prevent bleeding or cerebrospinal fluid leaks. However, in the context of Cushing's disease, ensuring oral hygiene is paramount due to increased risk of infection, especially if the patient is on corticosteroid therapy, which suppresses the immune system. B. Keeping the head of the bed at 30° helps prevent complications such as cerebral edema and increased intracranial pressure. While this is important post-hypophysectomy, it's not specific to Cushing's disease or a priority over oral care. C. Providing frequent mouth care is crucial in Cushing's disease due to increased cortisol levels leading to immunosuppression and susceptibility to infections. Additionally, glucocorticoid therapy can cause mucosal dryness and ulceration, necessitating meticulous oral hygiene. D. Monitoring intake and output is essential postoperatively to assess fluid balance and renal function. While important, it's not the priority in this context compared to oral care, especially considering the risk of dehydration due to increased cortisol levels in Cushing's disease.