Check if the patient has any of the following severity criteria:
Systolic blood pressure <100 mm Hg.
Arterial oxygen saturation <90%
Respiratory rate ⩾30 breaths per minute
Pulse ⩾110 beats per minute
Sudden or progressive dyspnea
Other serious complications, constituting admission criteria in and of themselves
Clinically relevant bleeding, high risk of bleeding, or platelets <50 000 mm−3.