MRCP2-4387

A 26-year-old asthmatic patient arrives at the emergency department with complaints of increased shortness of breath, wheezing, and a productive cough for several days. Upon examination, the patient has a respiratory rate of 40 breaths per minute and oxygen saturations (SpO2) of 88% on high flow oxygen. The patient’s blood pressure is 160/70 mmHg and pulse rate is 100 beats per minute. The peak expiratory flow rate is 35% of predicted, and the patient is unable to complete sentences. However, the PaCO2 is within the normal range. What feature of acute life-threatening asthma is present in this patient?