What are the anesthetic implications for a patient on buprenorphine (Subutex) undergoing surgery?

Anesthetic Implications of Patients on Buprenorphine

Perioperative management of patients on buprenorphine should be individualized based on the prescribed daily dose, indication for treatment (pain vs. dependency), risk of relapse, and expected level of postsurgical pain. 1

Pharmacological Properties and Anesthetic Considerations

• Buprenorphine is a partial mu-opioid receptor agonist with high receptor affinity that can cause respiratory depression similar to morphine at therapeutic doses 2
• It has a prolonged half-life (1.2-7.2 hours after IV administration) and undergoes N-dealkylation (primarily via CYP3A4) and glucuronidation 2
• QT prolongation of ≤15 msec has been demonstrated with buprenorphine, requiring caution when used with other QT-prolonging agents 2
• Buprenorphine may cause severe hypotension, including orthostatic hypotension and syncope, particularly in patients with compromised blood pressure regulation or when combined with certain CNS depressants 2

Perioperative Management Strategies

Current Guidelines and Recommendations

• The Society for Perioperative Assessment and Quality Improvement (SPAQI) recommends individualizing perioperative buprenorphine management based on patient-specific factors 1
• Recent evidence suggests continuing buprenorphine therapy perioperatively, with consideration of tapering to 12 mg daily 2-3 days before surgery if high postoperative pain is anticipated 1
• The Perioperative Pain and Addiction Interdisciplinary Network (PAIN) suggests that buprenorphine therapy be continued in the perioperative period, rarely recommending dose reduction 3

Specific Management Approaches

• For patients with anticipated low postoperative pain:

  • Continue buprenorphine at the regular dose throughout the perioperative period 1, 4

• For patients with anticipated moderate to severe postoperative pain:

  • Option 1: Continue buprenorphine but consider tapering to ≤12 mg daily 2-3 days before surgery 1
  • Option 2: For patients at high risk of relapse, maintain buprenorphine therapy and use higher doses of full mu-opioid agonists for breakthrough pain 4, 3

Pain Management Considerations

• Patients on buprenorphine may require higher doses of full mu-opioid agonists to achieve adequate analgesia due to partial blockade of opioid receptors 1
• Multimodal analgesia should be maximized, including:
  • Regional anesthesia techniques when appropriate 1, 5
  • Non-opioid adjuncts (NSAIDs, acetaminophen, membrane stabilizers) 1, 5
  • Local anesthetic infiltration by the surgeon 1

Potential Complications and Monitoring

• Monitor for potential drug-drug interactions that could result in QT-interval prolongation, serotonin syndrome, paralytic ileus, or precipitation of withdrawal symptoms 1, 2
• Patients may be at risk for respiratory depression, especially when buprenorphine is combined with other CNS depressants 2, 6
• Careful sedation monitoring is essential, particularly in elderly, cachectic, or debilitated patients who may have altered pharmacokinetics 2

Recent Evidence on Perioperative Outcomes

• A 2022 retrospective study found that patients who continued buprenorphine perioperatively had significantly lower postoperative opioid requirements compared to those who discontinued it 4
• This finding challenges earlier recommendations to discontinue buprenorphine before surgery 4, 3

Common Pitfalls and Caveats

• Abrupt discontinuation of buprenorphine in patients with opioid use disorder may precipitate withdrawal and increase risk of relapse 1, 3
• Concomitant use of buprenorphine with QT-prolonging agents is contraindicated 1
• Patients with adrenal insufficiency, increased intracranial pressure, or impaired consciousness require special consideration 2
• Coordination with the patient's buprenorphine provider is essential for perioperative planning and postoperative follow-up 5