Surgical Clearance Decision
Yes, this patient can proceed with elective surgery, as her blood pressure of 160/90 mmHg is below the threshold of 180/110 mmHg that would require postponement. 1, 2
Blood Pressure Threshold for Surgical Clearance
The patient meets criteria for surgical clearance because her BP is <180/110 mmHg. The Association of Anaesthetists of Great Britain and Ireland and British Hypertension Society jointly recommend that elective surgery should only be postponed if blood pressure is ≥180 mmHg systolic OR ≥110 mmHg diastolic. 1 This threshold is consistently supported across multiple guidelines, which emphasize that BP readings between 160-179/100-109 mmHg should not delay surgery. 2
Management of Resistant Hypertension in This Context
While this patient has resistant hypertension (elevated BP despite two antihypertensive agents including amlodipine and losartan), this does not preclude surgical clearance. 1 The guidelines explicitly state that patients may proceed to elective surgery even if they remain hypertensive despite optimal antihypertensive treatment. 1
Key action: Inform the primary care physician about the BP reading for long-term optimization of the antihypertensive regimen, but do not delay surgery. 2
Perioperative Medication Management
Continue both amlodipine and losartan through the perioperative period, with one important consideration:
- Continue amlodipine without interruption - calcium channel blockers should be maintained perioperatively 2
- Consider withholding losartan on the morning of surgery - ARBs are associated with greater perioperative hemodynamic instability and hypotension, though this decision should be made in consultation with anesthesia 2
- Never abruptly discontinue either medication preoperatively without a specific plan, as sudden withdrawal can cause adverse cardiovascular events 2
Rationale Behind This Approach
There is no evidence that acutely lowering blood pressure immediately before surgery reduces perioperative cardiovascular events. 2 The elevated BP measurements in surgical settings are often due to anxiety and stress ("white coat" phenomenon), making them less accurate than primary care readings. 2 Delaying surgery for BP 160/90 mmHg represents unnecessary delays that harm patients psychosocially and economically without improving outcomes. 2
Common Pitfalls to Avoid
- Do not cancel surgery for BP 160/90 mmHg - this is below the evidence-based threshold for postponement 1, 2
- Do not attempt acute BP reduction immediately before surgery - there is no evidence this improves outcomes 2
- Do not rely on a single BP measurement - ensure proper measurement technique with the patient seated, arm supported, in a relaxed environment, with multiple readings if the first is elevated 2, 3
- Do not forget to communicate with primary care - the patient's primary physician should be informed about the suboptimal BP control for long-term management optimization 2