Is it okay to increase continuous propofol (CPT) from 3.5 to 4 in a patient with hypertension and tachycardia during surgery?

Increasing Propofol Infusion for Intraoperative Hypertension and Tachycardia

Yes, it is appropriate to increase propofol from 3.5 to 4 mg/kg/h intraoperatively to manage hypertension and tachycardia, but this should be done cautiously with concurrent use of short-acting antihypertensive agents (clevidipine, nicardipine, or esmolol) rather than relying on propofol alone for blood pressure control. 1, 2

Primary Management Strategy

The preferred approach is to use dedicated short-acting IV antihypertensive agents rather than increasing sedative depth. 1

• For perioperative hypertension (BP ≥160/90 mmHg or SBP elevation ≥20% of preoperative value persisting >15 minutes), the ACC/AHA guidelines recommend clevidipine, esmolol, nicardipine, or nitroglycerin as first-line agents 1
• Intraoperative hypertension is most frequently seen during anesthesia induction and airway manipulation, and requires rapid BP lowering with titratable agents 1
• Continuous infusion of short-acting titratable antihypertensive agents is preferable to prevent target organ damage 1

Propofol Dosing Considerations

If increasing propofol infusion, the adjustment from 3.5 to 4 mg/kg/h remains within safe dosing parameters but carries hemodynamic risks. 3

• The FDA label indicates that ICU sedation maintenance rates typically range from 5-50 mcg/kg/min (0.3-3 mg/kg/h), with higher rates up to 4 mg/kg/h acceptable when benefits outweigh risks 3
• Administration should not exceed 4 mg/kg/h unless benefits outweigh risks, and higher rates increase likelihood of hypotension 3
• Your proposed increase from 3.5 to 4 mg/kg/h approaches the upper safety threshold 3

Critical Hemodynamic Concerns

Propofol causes dose-dependent vasodilation and myocardial depression, making it a suboptimal choice for treating sympathetically-mediated hypertension. 4, 5

• Each 0.3 mg/kg increase in propofol dose is associated with a 31% increase in hypotensive/bradycardic episodes requiring intervention 4
• Higher propofol doses (2.7 mg/kg versus 1.4 mg/kg) cause significantly greater SVR reduction (-31% versus -20%) without proportional benefit in BP control 5
• Propofol reduces cardiac output by 32-35% through combined effects on SVR, stroke volume, and heart rate 5

Paradoxical Effects

Low-dose propofol can paradoxically cause hypertension and tachycardia through vasoconstriction, making dose escalation unpredictable. 6

• Case reports demonstrate that small amounts of propofol can induce vasoconstriction rather than vasodilation 6
• This paradoxical response means increasing propofol may worsen rather than improve hypertension in some patients 6

Recommended Algorithm

Follow this stepwise approach: 1, 2

1. First, address reversible causes: Assess pain control, bladder distention, oxygenation, and volume status before pharmacological intervention 1

2. Second, use dedicated antihypertensive agents:

   • For hypertension with tachycardia: Esmolol 0.5-1 mg/kg bolus, then 50-300 mcg/kg/min infusion 1
   • For hypertension without tachycardia: Nicardipine 5 mg/h initially, titrate by 2.5 mg/h every 5-15 minutes (maximum 15 mg/h) 1
   • Clevidipine 1-2 mg/h initially, double every 90 seconds to desired effect 1

3. Third, optimize anesthetic depth: Only after addressing the above, consider modest propofol increase to 4 mg/kg/h if inadequate anesthetic depth is contributing 2, 3

4. Monitor closely: Maintain invasive arterial monitoring and be prepared to treat hypotension with phenylephrine or norepinephrine 2

Target Blood Pressure Goals

Maintain perioperative BP at 70-100% of baseline, avoiding both excessive peaks and profound hypotension. 1

• Decreases in BP >20 mmHg for >1 hour are associated with increased complications in hypertensive patients 1
• Avoid excessive reduction that may cause renal, cerebral, or coronary ischemia 1
• Maintain mean arterial pressure ≥60-65 mmHg to reduce risk of myocardial injury and acute kidney injury 7

Common Pitfalls to Avoid

• Do not use propofol as primary antihypertensive: It causes unpredictable hemodynamic effects and increases risk of hypotension 4, 5
• Do not give rapid boluses: This exacerbates hemodynamic instability in hypertensive patients 1
• Do not ignore underlying causes: Pain, light anesthesia, and sympathetic stimulation require specific treatment 1, 2
• Do not exceed 4 mg/kg/h without compelling indication: Risk-benefit ratio becomes unfavorable 3