Final answer:
When examining drainage after a transsphenoidal resection of the pituitary gland, a nurse should look for serosanguineous drainage surrounded by clear to straw-colored fluid, as it indicates cerebrospinal fluid (CSF) leakage.
Step-by-step explanation:
When a nurse suspects cerebrospinal fluid (CSF) leakage after a transsphenoidal resection of the pituitary gland, they should look for drainage that is serosanguineous, surrounded by clear to straw-colored fluid. Serosanguineous drainage refers to a mixture of blood and serous fluid. In this case, it indicates the presence of CSF.