Final answer:
The nurse anticipates observing purulent green-yellow drainage, which is indicative of a bacterial infection, often leading to rhinosinusitis.
Step-by-step explanation:
When a patient complains of nasal drainage and sinus headache, and a nasal infection is suspected based on these symptoms, the nurse anticipates observing purulent green-yellow drainage. This type of drainage is typically indicative of an infection, often caused by bacteria such as S. pneumoniae, H. influenzae, or M. catarrhalis. These organisms can lead to rhinosinusitis, which is an infection and inflammation of the paranasal sinuses. Other symptoms may include swelling and redness in the nasal passages, similar to signs observed in acute, purulent bacterial infections elsewhere such as conjunctivitis.