Refer a patient with suspected pulmonary embolism to secondary care if they have signs of haemodynamic instability, such as cardiac arrest, obstructive shock, or persistent hypotension, as these require immediate hospital admission NICE CKS.
For patients without haemodynamic instability, use the two-level PE Wells score to determine the need for secondary care referral: a score of more than 4 points indicates PE is likely, and hospital admission for immediate investigation (e.g., CTPA) is recommended NICE CKS.
If the Wells score is 4 or less, a D-dimer test should be performed. If positive, hospital admission for investigation is advised; if negative, secondary care referral may not be necessary unless other clinical concerns arise NICE CKS.
Patients with signs or symptoms of PE, such as chest pain, shortness of breath, or coughing up blood, should be considered for urgent hospital assessment, especially if initial assessments suggest high risk NICE NG158,NICE CKS.