How should a patient with chronic hypertension be evaluated and managed before, during, and after surgery, including blood pressure targets, antihypertensive medication adjustments, intra‑operative monitoring, and treatment of hypertensive crises?

Perioperative Management of Hypertension

Preoperative Assessment and Blood Pressure Thresholds

Elective surgery should proceed if blood pressure is <180/110 mmHg, regardless of hypertension stage, as this threshold does not independently increase perioperative cardiovascular risk. 1

Blood Pressure Measurement Standards

• Measure blood pressure in a relaxed, temperate environment with the patient seated and arm supported for at least one minute before initial reading 1
• Use validated automated sphygmomanometers for regular rhythm; use manual auscultation over the brachial artery for irregular pulse 1
• Measure both arms in patients scheduled for vascular or renal surgery; if systolic difference exceeds 20 mmHg, repeat and subsequently measure from the higher arm 1
• Obtain blood pressure readings from primary care within the preceding 12 months before non-urgent surgical referral 1

Risk Stratification

• Stage 1-2 hypertension (140-179/90-109 mmHg) without target organ damage does not clearly increase perioperative cardiovascular complications 1, 2
• Evaluate specifically for target organ damage (cardiac dysfunction, renal impairment, cerebrovascular disease) as this—not blood pressure elevation alone—determines perioperative risk 1, 2
• Deferring surgery may be considered only for poorly controlled hypertension (SBP ≥180 or DBP ≥110 mmHg) in patients with cardiovascular risk factors and elevated-risk surgery 1
• Emergency or urgent surgery must proceed regardless of blood pressure control 2

Medication Management

Continue Through Surgery

• Continue beta-blockers, calcium channel blockers, and diuretics through the morning of surgery 3, 2
• Abrupt withdrawal of beta-blockers precipitates rebound hypertension and silent myocardial ischemia that is easily missed without continuous ECG monitoring and serial troponin measurements 1, 2
• Sudden withdrawal of clonidine and alpha-methyldopa also causes adverse rebound phenomena 1

Withhold on Day of Surgery

• Omit ACE inhibitors and angiotensin receptor blockers on the day of surgery to reduce significant perioperative hemodynamic fluctuations 1, 3, 2
• This practice is associated with fewer intraoperative hypotensive episodes 1
• Resume ACE inhibitors and ARBs as soon as oral intake is established postoperatively 3, 4

Avoid Initiating Perioperatively

• Do not initiate beta-blockade perioperatively in high cardiac-risk patients, as the POISE-1 study demonstrated increased postoperative mortality secondary to hypotension and stroke 1

Intraoperative Management

Blood Pressure Targets

• Maintain intraoperative MAP ≥60-65 mmHg or SBP ≥90 mmHg to reduce risk of myocardial injury, acute kidney injury, and mortality 1
• The harm threshold appears to be MAP <65 mmHg or SBP <90 mmHg maintained for approximately 15 minutes 1
• In older adults and those with chronic hypertension, target higher blood pressures (approximately 10% above baseline rather than aggressive normalization) 4
• Avoid excessive blood pressure reduction that may cause renal, cerebral, or coronary ischemia 3

Hemodynamic Considerations

• Expect pronounced sympathetic activation with laryngoscopy, intubation, and emergence causing significant blood pressure and heart rate increases 3, 2
• Hypertensive patients demonstrate more labile hemodynamic profiles with exaggerated responses to induction, surgical stimulation, pain, and emergence 1, 3, 4
• Intraoperative hypotension is paradoxically more common in hypertensive patients, particularly during induction and in fluid-depleted states 1

Anesthetic Techniques for Hemodynamic Stability

• Use co-induction techniques to blunt the hypertensive response to laryngoscopy and intubation 1, 3
• Implement invasive arterial monitoring with titrated or prophylactic vasopressor therapy for high-risk patients 1, 3
• Optimize stroke volume with intravascular fluid therapy guided by dynamic indices 1, 3
• Consider depth-of-anesthesia monitoring to prevent awareness and inadequate anesthesia that triggers hypertensive responses 1
• Use phenylephrine or norepinephrine for hypotension to maintain coronary perfusion pressure 3

Management of Intraoperative Hypertensive Crisis

First-Line Approach

• Address reversible causes first: inadequate analgesia, light anesthesia, bladder distention, hypoxemia, hypercarbia, and volume overload 3
• Pain control and adequate anesthetic depth are the most common correctable causes 3

Pharmacologic Management

• Use short-acting IV antihypertensive agents (clevidipine, esmolol, nicardipine, or nitroglycerin) as first-line therapy for perioperative hypertension 3
• Continuous infusion of titratable agents is preferable to prevent target organ damage 3
• Clevidipine lowers blood pressure within 2-4 minutes; initiate at 1-2 mg/hour and titrate upward in doubling increments every 90 seconds up to 16 mg/hour, then increase by 7 mg/hour increments as needed 5
• Avoid rapid boluses of antihypertensive agents as they exacerbate hemodynamic instability 3

Target Blood Pressure During Crisis

• Maintain perioperative blood pressure at 70-100% of baseline 3
• Avoid decreases in blood pressure >20 mmHg for >1 hour, as this is associated with increased complications 3
• Do not aggressively normalize blood pressure; gradual reduction prevents cerebral, coronary, and renal hypoperfusion 3, 4

Postoperative Management

Blood Pressure Monitoring and Control

• Continue invasive monitoring for 24-48 hours postoperatively as hemodynamic changes persist 3
• Treat postoperative hypertension aggressively, as it affects 25% of major surgery patients and increases risk of cardiovascular events, stroke, and bleeding 4
• Resume oral antihypertensives as soon as clinically feasible; delaying resumption increases 30-day mortality 4
• Bridge with IV antihypertensives (nicardipine infusion) until oral medications are tolerated 4

Hypotension Avoidance

• Target MAP ≥60-65 mmHg postoperatively to limit cardiovascular, cerebrovascular, and renal complications 4
• Even brief hypotensive episodes may significantly impact outcome, particularly in elderly patients with prior stroke or cardiovascular disease 4

Emergence Management

• Anticipate exaggerated hemodynamic response to emergence and extubation—this is more common in hypertensive patients 3, 2
• Ensure adequate analgesia before emergence to blunt sympathetic response 3
• Consider prophylactic short-acting antihypertensive (labetalol or esmolol) before extubation 3

Common Pitfalls

• Do not delay elective surgery solely for blood pressure control in patients with BP <180/110 mmHg without target organ damage 1
• Do not abruptly discontinue beta-blockers perioperatively 1, 2
• Do not continue ACE inhibitors/ARBs on the day of surgery 1, 3
• Do not ignore underlying causes of intraoperative hypertension (pain, light anesthesia) and treat only with antihypertensives 3
• Do not use rapid boluses of antihypertensive agents; use continuous infusions of titratable agents 3
• Do not aggressively normalize blood pressure in elderly or chronically hypertensive patients; target 10% above baseline 4