Acute pain in the opioid-tolerant patient
Stem
A 48-year-old man, 105 kg, is scheduled for an L4–S1 posterior instrumented fusion. For chronic low back pain he takes extended-release oxycodone 40 mg twice daily and immediate-release oxycodone 10 mg about four times a day. He has obstructive sleep apnea on CPAP. He says the last time he had surgery "nothing touched the pain" and he was "treated like an addict."
Question
How will you manage his pain before, during and after surgery?
Ideal answer
HeadlineI cover his baseline against withdrawal, add non-opioid analgesia to cut his total opioid need, and monitor closely for his sleep apnea.
- His extended-release oxycodone on the morning of surgery: maintained, not treated as the pain plan, and continued afterward.1
- Ketamine about 35 mg before incision, then low-dose infusion, under the 0.35 mg/kg ceiling and below the 1 mg/kg per hour consensus limit, for one to three days;2,1 acetaminophen too.
- Wound infiltration or a catheter from the surgeon, because regional and local techniques spare opioids.1
- Opioid titrated to respiratory rate at emergence, not to a usual dose; then IV PCA with a larger-than-standard bolus, titrated to effect and sedation, on top of his oral baseline.1
- Continuous pulse oximetry and capnography, CPAP from recovery, because supplemental oxygen delays detecting hypoventilation; sedation is the warning sign.3
Breaking down the answer
- Baseline plus acute pain — his daily opioid is maintenance; the surgical pain is added to it. Withholding baseline produces withdrawal that looks like uncontrolled pain.1
- Ketamine is the main opioid-sparing adjunct — the consensus summary singles out patients with opioid dependence and acute pain, and active substance use is not a contraindication in acute pain.2 Contraindications include poorly controlled cardiovascular disease, pregnancy, active psychosis and severe liver disease.2
- Tolerance versus hyperalgesia — tolerance responds to more opioid or rotation; opioid-induced hyperalgesia gets worse with more and is treated by reducing the dose.1 Recognizing which one you face shows adaptability.
- Address the stigma — I tell him I take his pain seriously and that he will need more opioid than most patients; a plain, respectful explanation earns trust and makes him report pain accurately. That is professionalism.
Follow-up question
The pharmacist calls the morning of surgery: the medication history was wrong. He actually takes sublingual buprenorphine-naloxone 16 mg daily for opioid use disorder, not oxycodone, and he took this morning's dose. The surgical resident wants to cancel and stop the buprenorphine for a week. What do you advise?
Follow-up answer
HeadlineThis changes the drugs, not the decision to operate. I tell the resident and surgeon that multisociety guidance is not to routinely stop buprenorphine.4
Adequate analgesia is achievable, stopping raises the risk of relapse, and tapering should be avoided even at higher doses.4 I proceed with the same multimodal plan, ketamine and regional or local techniques as the foundation.4 If pain is still uncontrolled, I add a full mu agonist, or increase or divide his buprenorphine into two or three doses, with close monitoring.4 I contact his outpatient prescriber and plan his usual dose after discharge, with a naloxone prescription.4 I reassess pain and sedation every few hours.
Pitfalls that cost points
- Holding the baseline opioid because the patient is NPO.
- Labeling every pain complaint drug-seeking.
Rapid-fire
Q: What is the maximum ketamine bolus in the consensus guidelines? A: 0.35 mg/kg.2
Q: Why does a methadone patient need a naloxone infusion if he becomes narcotized? A: Methadone's half-life of 24 to 36 hours far outlasts naloxone's.5
Q: What intraoperative methadone dose has been studied in adults? A: Typically 20 mg or 0.2 mg/kg as a single dose; the ideal dose is not established.5
Q: What do you do with a methadone maintenance dose on the day of surgery? A: Continue it.1
Q: Why is supplemental oxygen a monitoring problem? A: It keeps saturation normal while CO2 rises, so it delays recognizing hypoventilation.3
Numbers to know
| Item | Value |
|---|---|
| Ketamine bolus ceiling | 0.35 mg/kg2 |
| Ketamine infusion ceiling, acute pain | 1 mg/kg/h2 |
| Ketamine infusion duration | 1–3 days1 |
| Methadone half-life | 24–36 h5 |
| Studied intraoperative methadone | 20 mg or 0.2 mg/kg5 |
Links
- PCA and multimodal analgesia, Opioids and postoperative respiratory depression, Substance use: opioids, cocaine, alcohol withdrawal, Dexmedetomidine and ketamine, Obstructive sleep apnea
- ASRA/AAPM/ASA consensus guidelines on intravenous ketamine for acute pain (2018); multisociety buprenorphine perioperative recommendations (2021)
Sources
- 1.Opioid tolerance or methadone-using patients · NYSORA · nysora.com
- 2.Intravenous Ketamine Guidelines for Pain Management · ASRA Pain Medicine, 2018 · asra.comSummary of the 2018 ASRA/AAPM/ASA ketamine consensus guidelines (Schwenk, Reg Anesth Pain Med 2018;43:456-66).
- 3.Monitoring for Opioid-Induced Respiratory Depression · APSF · apsf.org
- 4.Buprenorphine Management in the Perioperative Period: multisociety expert panel recommendations · Guideline Central / ASRA Pain Medicine, 2021 · guidelinecentral.comSummary of Kohan L, et al. Reg Anesth Pain Med 2021;46:840-59.
- 5.Use of Methadone in the Perioperative Period · APSF · apsf.org
Facts on this page were checked against these sources on Oct 15, 2026. Guidelines change; confirm doses against current institutional protocols.