Final answer:
The most appropriate intervention after oxygen therapy for a severe asthma attack with potential airway compromise due to laryngospasm is 0.3-0.5 mL (1:1000) of epinephrine delivered IM/SC; repeat in 15 minutes if needed.
Step-by-step explanation:
Based on the presented scenario, the most appropriate intervention after applying oxygen therapy would be option D: 0.3-0.5 mL (1:1000) of epinephrine delivered IM/SC; repeat in 15 minutes if needed.
Epinephrine is commonly used in severe asthma attacks to relieve airway constriction and laryngospasm. It acts as a bronchodilator, opening up the airways and allowing easier airflow. IM (intramuscular) or SC (subcutaneous) delivery is used when there is potential airway compromise.