When presented with a 47-year-old male who is having difficulty breathing and cannot stop coughing, what should you do first?

In a situation where a patient is experiencing difficulty breathing and persistent coughing, the priority is to manage the airway and ensure adequate oxygenation. Administering oxygen is critical because it directly addresses the potential hypoxia the patient may be experiencing due to respiratory distress. Supplemental oxygen helps to stabilize the patient's condition by improving oxygen delivery to the tissues, which is essential until further assessments and interventions can be made.

While understanding the patient's medical history and assessing vital signs are important steps in overall patient care, these can be performed after ensuring that the patient is receiving adequate oxygen. Collecting a sample of phlegm may be necessary for diagnostic purposes but is not an immediate action when a patient is in respiratory distress. The primary goal in this scenario is to secure the airway and provide oxygen as needed, which makes administering oxygen the most appropriate first response.