What immediate treatment is indicated for a patient with myasthenia gravis who presents with pneumonia?

In the case of a patient with myasthenia gravis who presents with pneumonia, the immediate treatment that should be prioritized is antibiotic therapy. Myasthenia gravis is an autoimmune disorder that causes weakness in the skeletal muscles, including those involved in breathing. When a patient with this condition develops pneumonia, it can exacerbate their respiratory difficulties due to weakened respiratory muscles.

Antibiotic therapy is critical as it targets the underlying infection causing pneumonia, thereby helping to reduce respiratory distress and improve the patient's overall condition. Prompt treatment of the pneumonia can prevent further complications, particularly since patients with myasthenia gravis may already have limited respiratory reserve.

While oxygen therapy might be considered as a supportive measure for hypoxemia, it does not address the underlying infection. Intubation is an invasive procedure that would be indicated if the patient’s respiratory status significantly worsens, but it is not an immediate treatment; rather, it is reserved for severe cases or failure of non-invasive support. Pulmonary function testing is important for assessing respiratory function but is not a treatment and should not delay the initiation of antibiotics when an infection is present.