MRCP2-4500

MRCP2-4500

A 30-year-old man with a history of asthma presents to the Emergency Department with an acute exacerbation of his condition. He typically manages his asthma well with inhaled fluticasone twice daily and salbutamol inhaler as needed. However, he reports progressively worsening shortness of breath over the past few days, requiring multiple doses of salbutamol per day. On examination, he is visibly distressed with a respiratory rate of 26 breaths per minute and unable to complete sentences in one breath. Bilateral expiratory polyphonic wheezes and poor air entry are noted. Arterial blood gases on air reveal a PaCO2 of 3.6 kPa/27 mmHg, PaO2 of 10 kPa/75 mmHg, pH of 7.45, and standard bicarbonate of 24 mmol/L. The casualty officer initiates high flow oxygen and continuous nebulised salbutamol, as well as administering 200 mg of hydrocortisone IV and one dose of nebulised ipratropium bromide. However, there is no improvement after 30 minutes of treatment. What would be the most appropriate next step in management?