A patient presents with SpO2 of 91% and an alert mental status, what should be your first action?

The best initial action for a patient presenting with an SpO2 of 91% and an alert mental status is to administer a nasal cannula at 4 liters per minute. This is because the oxygen saturation level of 91% indicates that the patient is experiencing hypoxemia, but since they are alert, there is a window of opportunity to improve their oxygenation without immediately resorting to more invasive measures.

Administering supplemental oxygen via a nasal cannula can help increase the patient's oxygen saturation to a safer level, enabling better tissue oxygenation while also allowing the patient to maintain an alert state. This approach is often used in cases of mild to moderate hypoxemia where the patient is still responsive and not in immediate distress.

By choosing this route first, the healthcare provider can effectively address the low oxygen saturation while also continuing to monitor the patient’s condition for any changes. If the situation worsens or if there are concerns about the patient's airway or breathing, additional interventions, such as calling for advanced support or monitoring closely, can then be pursued.