How should hypertension be managed in patients undergoing surgery?

Management of Hypertension in Patients Undergoing Surgery

In patients with hypertension undergoing surgery, beta blockers should be continued if the patient has been on them chronically, while ACE inhibitors or ARBs may be discontinued perioperatively to reduce the risk of intraoperative hypotension. 1

Preoperative Management

Continuation vs. Discontinuation of Medications

• Beta blockers should be continued in patients who have been taking them chronically, particularly when prescribed according to guideline-directed medical therapy (e.g., for myocardial infarction) 1
• Abrupt preoperative discontinuation of beta blockers or clonidine is potentially harmful due to risk of rebound hypertension 1
• Discontinuation of ACE inhibitors or ARBs perioperatively (24-36 hours before surgery) may be considered to reduce the risk of intraoperative hypotension 1, 2
• It is reasonable to continue other antihypertensive medications until the day of surgery 1
• Beta blockers should NOT be started on the day of surgery in beta blocker-naïve patients 1

Blood Pressure Thresholds

• For patients with planned elective major surgery and severe hypertension (SBP ≥180 mmHg or DBP ≥110 mmHg), deferring surgery may be considered 1
• For most patients, it is reasonable to aim for blood pressure control to levels <130/80 mmHg before undertaking major elective procedures 1

Intraoperative Management

• Patients with intraoperative hypertension should be managed with intravenous medications until oral medications can be resumed 1
• Intraoperative hypertension is most frequently seen during anesthesia induction and airway manipulation 1
• Perioperative hypertension is defined as BP ≥160/90 mmHg or SBP elevation ≥20% of the preoperative value that persists for >15 minutes 1

Recommended IV Medications for Perioperative Hypertension

• Clevidipine: Safe and effective for acute hypertension in cardiac surgery patients 1
• Esmolol: Short-acting beta blocker useful for perioperative hypertension 1
• Nicardipine: Effective for perioperative hypertension with dose-dependent decreases in blood pressure 1, 3
• Nitroglycerin: Indicated for perioperative hypertension management 1, 4

Special Considerations

• Spinal anesthesia combined with ACE inhibitors may result in severe hypotension, supporting the recommendation to withdraw ACEIs well in advance of spinal anesthesia 5
• Discontinuing ACE inhibitors/ARBs does not result in a significant increase in pre- or postoperative hypertension compared to patients who continued these medications 2
• Calcium channel blockers can be safely continued up to the day of surgery without provoking problems with cardiovascular stability 5, 6
• Diuretics should be discontinued on the day of surgery and resumed in the postoperative period to avoid dehydration and electrolyte abnormalities 6

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 1
• Exaggerated responses may occur in patients with poorly treated or untreated hypertension (up to 90 mmHg and 40 bpm) 1
• Patients with controlled hypertension typically respond similarly to normotensive patients during anesthesia 1
• Assess other potential contributing factors to perioperative hypertension, such as volume status, pain control, oxygenation, and bladder distention 1

Common Pitfalls and Caveats

• Avoid abrupt discontinuation of beta blockers or clonidine as this can lead to rebound hypertension 1
• Do not start beta blockers on the day of surgery in beta blocker-naïve patients as this increases risk of harm 1
• Be aware that nitrates given in the presence of phosphodiesterase-5 inhibitors may induce profound hypotension 1
• Recognize that uncontrolled hypertension is associated with increased perioperative and postoperative complications including CVD, cerebrovascular events, and bleeding 1
• Consider that hypertensive patients undergoing carotid endarterectomy have increased risk of postoperative hypertension and neurological defects 1