Management of Hypertension in Patients Undergoing Surgery

Preoperative Management

• The American College of Cardiology recommends that beta blockers should be continued in patients who have been taking them chronically, particularly when prescribed according to guideline-directed medical therapy, to reduce the risk of rebound hypertension 1, 2
• Abrupt preoperative discontinuation of beta blockers or clonidine is potentially harmful due to risk of rebound hypertension, as stated by the American College of Cardiology 2, 3
• Discontinuation of ACE inhibitors or ARBs perioperatively may be considered to reduce the risk of intraoperative hypotension, according to the American Heart Association 4, 2
• The American College of Cardiology suggests that it is reasonable to continue other antihypertensive medications until the day of surgery, except for ACE inhibitors or ARBs 5, 6
• Beta blockers should NOT be started on the day of surgery in beta blocker-naïve patients, as recommended by the American College of Cardiology, due to increased risk of harm 2, 7

Blood Pressure Thresholds

• For patients with planned elective major surgery and severe hypertension, deferring surgery may be considered if blood pressure is ≥180/110 mmHg, as suggested by the American College of Cardiology 2, 8
• The American Heart Association recommends aiming for blood pressure control to levels <130/80 mmHg before undertaking major elective procedures 8, 9

Intraoperative Management

• Patients with intraoperative hypertension should be managed with intravenous medications, such as clevidipine, esmolol, or nicardipine, until oral medications can be resumed, as stated by the American College of Cardiology 1, 2
• Intraoperative hypertension is most frequently seen during anesthesia induction and airway manipulation, according to the American Heart Association 5, 3
• Perioperative hypertension is defined as BP ≥160/90 mmHg or SBP elevation ≥20% of the preoperative value that persists for >15 minutes, as defined by the American College of Cardiology 5, 4

Monitoring and Follow-up

• During induction of anesthesia, sympathetic activation can result in a 20–30 mmHg increase in BP and a 15-20 bpm increase in heart rate in normotensive patients, as reported by the American Heart Association 8
• Exaggerated responses may occur in patients with poorly treated or untreated hypertension, with increases up to 90 mmHg and 40 bpm, according to the American College of Cardiology 8
• Patients with controlled hypertension typically respond similarly to normotensive patients during anesthesia, as stated by the American Heart Association 8
• Assess other potential contributing factors to perioperative hypertension, such as volume status, pain control, oxygenation, and bladder distention, as recommended by the American College of Cardiology 7

Common Pitfalls and Caveats

• Avoid abrupt discontinuation of beta blockers or clonidine as this can lead to rebound hypertension, as warned by the American College of Cardiology 2, 3
• Do not start beta blockers on the day of surgery in beta blocker-naïve patients as this increases risk of harm, according to the American College of Cardiology 2, 7
• Be aware that nitrates given in the presence of phosphodiesterase-5 inhibitors may induce profound hypotension, as cautioned by the American Heart Association 5, 4
• Recognize that uncontrolled hypertension is associated with increased perioperative and postoperative complications, including cardiovascular disease, cerebrovascular events, and bleeding, as stated by the American College of Cardiology 2, 7
• Consider that hypertensive patients undergoing carotid endarterectomy have increased risk of postoperative hypertension and neurological defects, as reported by the American Heart Association 8

Management of Oral Blood Pressure Medications in NPO Patients for Surgery

Preoperative Management of Antihypertensive Medications

• The American College of Cardiology recommends that patients who are NPO for surgery should continue taking their oral blood pressure medications with a small sip of water on the morning of surgery, with the exception of ACE inhibitors and ARBs which may be discontinued 24 hours before surgery, to reduce the risk of intraoperative hypotension 10, 11, 12
• Beta blockers should be continued in patients who have been taking them chronically, particularly when prescribed according to guideline-directed medical therapy, to reduce the risk of rebound hypertension 10
• Diuretics for hypertension can typically be discontinued on the day of surgery and resumed orally when possible, according to the European Society of Cardiology 13
• Diuretics for heart failure should be continued up to the day of surgery, as recommended by the European Society of Cardiology 13
• ACE inhibitors or ARBs may be discontinued 24 hours before surgery to reduce the risk of intraoperative hypotension, as suggested by the American Heart Association 10, 14

Blood Pressure Thresholds and Surgical Timing

• The American Heart Association recommends aiming for blood pressure control to levels <130/80 mmHg before undertaking major elective procedures, with a strength of evidence classified as moderate 14
• For patients with planned elective major surgery and severe hypertension (≥180/110 mmHg), deferring surgery may be considered, according to the American College of Cardiology 10, 11, 12

Intraoperative Management

• If oral medications cannot be taken, intravenous alternatives should be used to maintain blood pressure control, as recommended by the American College of Cardiology 10, 14
• Patients with intraoperative hypertension should be managed with intravenous medications (such as clevidipine, esmolol, or nicardipine) until oral medications can be resumed, according to the American College of Cardiology 10, 12

Special Considerations for Specific Medications

• For patients on diuretics, electrolyte disturbances (especially hypokalemia and hypomagnesemia) should be corrected before surgery, as recommended by the European Society of Cardiology 13

Peri‑operative Hemodynamic Management in Patients with Chronic Hypertension

1. Impaired Autoregulation and Risk of Hypotension with Neuraxial Anesthesia

• Chronic hypertension induces structural vascular remodeling that blunts normal autoregulatory responses, increasing susceptibility to hypotension during spinal anesthesia【15】.
• The splanchnic circulation lacks intrinsic autoregulation; therefore gut perfusion becomes dependent on mean arterial pressure (MAP) and cardiac output, making it especially vulnerable when MAP falls【16】.
• Spinal anesthesia produces a profound sympathetic blockade, eliminating the sympathetic tone that normally maintains vascular tone below the block level【16】.
• Loss of compensatory vasoconstriction below the block level leads to venous pooling and further drops in arterial pressure【16】.
• Intra‑operative hypotension should be avoided because it compromises gut perfusion and anastomotic integrity; appropriate use of pure‑α vasopressors such as phenylephrine or low‑dose norepinephrine is recommended【16】.

2. Avoidance of Tachycardia and Preferred Vasopressor Choice

• Hypertensive patients frequently have underlying coronary artery disease, so tachycardia markedly raises myocardial oxygen demand and can precipitate ischemia【15】.
• Intra‑operative hemodynamic instability, including episodes of tachycardia, is an independent predictor of postoperative myocardial infarction in this population【15】.
• Phenylephrine or low‑dose norepinephrine (pure α‑agonists) are strongly recommended for treating intra‑operative hypotension because they raise blood pressure without increasing heart rate【16】.
• Maintaining MAP above 55 mmHg while avoiding tachycardia helps preserve organ perfusion, particularly of the gastrointestinal tract【16】.

3. Pharmacologic Strategies for Hypertensive Crises (Intra‑operative)

• Clevidipine – endorsed by the American College of Cardiology/American Heart Association (ACC/AHA) for intra‑operative hypertension; it is a potent arteriolar vasodilator that does not cause direct myocardial depression【15】.
• Nicardipine – also recommended by ACC/AHA for intra‑operative blood‑pressure control; it acts as a potent arteriolar vasodilator【15】.
• Continuation of renin‑angiotensin system blockade (ACE‑inhibitors/ARBs) peri‑operatively can further impair compensatory mechanisms in hypertensive patients, increasing the risk of hypotension after neuraxial blockade【15】.

All facts are derived from peer‑reviewed sources indicated by the citation IDs.