This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: COPD and Asthma, Subject name: Medicine
A 4-year-old girl asthmatic child is brought to casualty. She is not speaking and has fast shallow breathing with pulsus paradoxsus. ABG shows respiratory acidosis. What is the next best step in management of this patient? 
Select and explain. 
A. Urgent endotracheal intubation, B. Hyperbaric oxygen therapy, C. MDI with salbutamol and coicosteroids, D. Terbutaline subcutaneous with aminophylline drip
A: Urgent endotracheal intubation
Answer: A: Urgent endotracheal intubation 
Explanation: 1. | CO2 - Respiratory acidosis - pulsus paradoxus 2. Patients not speaking - Imminent respiratory arrest | Do urgent Endotracheal intubation Other option Hyper baric oxygen therapy - CO poisoning, HAPE(High altitude pulmonary edema) MDI with salbutamol - patient cannot inhale Aminophylline - may cause PSVT