Why is positive-pressure ventilation difficult with a patient who has anaphylaxis?

Why is positive-pressure ventilation difficult with a patient who has anaphylaxis?

• A. Airway swelling blocks airflow
• B. Low oxygen content due to anemia
• C. The patient is drowsy
• D. High blood pressure impairs ventilation

Answer: (A)

Airway swelling blocks airflow. In anaphylaxis, mediators cause rapid edema of airway tissues—the tongue, throat, and larynx—often with bronchospasm as well. This narrows or closes the airway, so air cannot reach the lungs even when you try to deliver it under positive pressure. The core challenge of ventilation in this scenario is the obstructed airway, not low oxygen content from anemia, a drowsy mental state, or high blood pressure. Treating the swelling promptly and securing the airway are crucial steps alongside oxygen and medications.

Airway swelling blocks airflow. In anaphylaxis, mediators cause rapid edema of airway tissues—the tongue, throat, and larynx—often with bronchospasm as well. This narrows or closes the airway, so air cannot reach the lungs even when you try to deliver it under positive pressure. The core challenge of ventilation in this scenario is the obstructed airway, not low oxygen content from anemia, a drowsy mental state, or high blood pressure. Treating the swelling promptly and securing the airway are crucial steps alongside oxygen and medications.