The nurse is caring for a 48-year-old-client admitted with complaints of fatigue and hemoptysis, but no other significant medical history. Social history includes smoking 1 pack/day x 20 years and occasional alcohol use. He denies taking any medication. The Mantoux test placed 72 hours earlier reveals an indurated area of 4 cm. Which action will the nurse plan to include in the care for this client?

Antihistamines primarily work by blocking the H1 receptors, which are the receptors responsible for mediating the actions of histamine in the body. By blocking these receptors, antihistamines prevent or reduce the effects of histamine, such as itching, sneezing, runny nose, and watery eyes. This is the main mechanism by which antihistamines provide their therapeutic effects. "Antihistamines block release of histamine from mast cells and basophils." This statement is incorrect. Antihistamines do not block the release of histamine; instead, they block the histamine receptors to prevent the effects of histamine.

"H1 antagonists can bind to H1 receptors, H2 receptors, and muscarinic receptors." This statement is incorrect. H1 antagonists, or H1 receptor blockers, specifically bind to H1 receptors and do not have significant affinity for H2 receptors or muscarinic receptors. "First-generation antihistamines are more selective than second-generation antihistamines." This statement is incorrect. First-generation antihistamines are generally less selective and can have more sedating and anticholinergic effects compared to second-generation antihistamines, which are designed to be more selective for H1 receptors and have reduced sedative properties.

The client's complaint of hemoptysis (coughing up blood) and a positive Mantoux test (4 cm induration) suggest the possibility of tuberculosis (TB) infection. TB is an airborne infectious disease, and placing the client in airborne isolation is necessary to prevent the spread of the infection to others.

Antibiotics may be used to treat tuberculosis, but the initial step would be to isolate the client and confirm the diagnosis before starting specific treatment.

A CT scan may be ordered to further evaluate the client's condition, but it is not the immediate action required in this case. Isolation and confirmation of the diagnosis take priority. While the client may require oxygen therapy based on their respiratory symptoms, it is not the primary action to take at this stage. Isolation and further evaluation are necessary before initiating specific treatments.