Question category: Respiratory
A 25 year old female has an acute asthma attack. She is tachycardic and is tachypnoeic with a respiratory rate of 35. On auscultation she is very wheezy but is beginning to tire. Her peak flow is bout one third of her normal. She is commenced on both salbutamol and ipratropium nebulisers and IV hydrocortisone however has not greatly improved. Her gases reveal a high normal CO2 level and low normal O2 level on a trauma mask. Which other treatment option is the most appropriate to be be tried whilst waiting for ITU to assess the patient?