The nurse assesses a patient with pneumonia on 2 L/min per nasal cannula with an oxygen saturation of 92% and notes decreased lung sounds to the bases with decreased lower lung expansion. What is the nurse's best action?

Choice A reason: While arterial blood gas analysis provides detailed information about oxygenation and ventilation, it is invasive and not the first-line intervention when oxygen saturation is acceptable and the patient is stable. Choice B reason: Rechecking oxygen saturation in one hour may delay necessary interventions. The patient already shows signs of decreased lung expansion, which requires active management. Choice C reason: Increasing oxygen to 6 L/min without reassessing the need or consulting the provider may lead to oxygen toxicity, especially in patients with chronic respiratory conditions. The current saturation is adequate. Choice D reason: Using an incentive spirometer promotes lung expansion, improves ventilation, and helps prevent atelectasis. It is a non-invasive and effective intervention for patients with pneumonia and decreased lung sounds.