When should I consider referring a patient with resistant hypertension to a specialist?

You should consider referring a patient with resistant hypertension to a specialist if their blood pressure remains uncontrolled while they are taking the optimal tolerated doses of four antihypertensive drugs ¹,².

Understanding Resistant Hypertension and Initial Steps:

• A patient is considered to have resistant hypertension if their blood pressure is not controlled despite taking optimal tolerated doses of a combination of three drugs: an ACE inhibitor or ARB, a calcium channel blocker (CCB), and a thiazide-like diuretic ¹,².
• Before considering further treatment for resistant hypertension, it is important to confirm elevated clinic blood pressure measurements using ambulatory blood pressure monitoring (ABPM) or home blood pressure monitoring (HBPM) ¹,². You should also assess for postural hypotension and discuss the patient's adherence to their medication ¹,².
• For patients with confirmed resistant hypertension, the next step (Step 4 treatment) involves either adding a fourth antihypertensive drug or seeking specialist advice ¹,². The choice of the fourth drug depends on the patient's blood potassium level: low-dose spironolactone is considered if potassium is 4.5 mmol/l or less, while an alpha-blocker or beta-blocker is considered if potassium is more than 4.5 mmol/l ¹,².

Other Urgent Specialist Referral Criteria (not specific to resistant hypertension but important for severe hypertension):

Refer people for specialist assessment, carried out on the same day, if they have a clinic blood pressure of 180/120 mmHg or higher with any of the following ¹,²:

• Signs of retinal haemorrhage or papilloedema (accelerated hypertension) ¹,².
• Life-threatening symptoms such as new onset confusion, chest pain, signs of heart failure, or acute kidney injury ¹,².

Additionally, refer people for same-day specialist assessment if a phaeochromocytoma is suspected (e.g., with labile or postural hypotension, headache, palpitations, pallor, abdominal pain, or diaphoresis) ¹,².