Opioid-tolerant and chronic pain patient — perioperative care

[1]

Why this is examined / the one-line answer

Opioid-tolerant and chronic pain patients are everyday major list and APS (acute pain service) work. Examiners test whether you understand tolerance vs addiction language, continue baseline opioids, build a multimodal and regional stack, adjust PCA, and discharge safely — without moralising or creating a new long-term high-dose problem.[1]

One-liner: I continue baseline oral morphine equivalent, add regional and non-opioid multimodal analgesia, escalate acute opioids thoughtfully with monitoring, involve APS early, and plan taper at discharge. [1]

Language that matters (say it cleanly)

Withholding analgesia because of stigma is not a management plan. [1]

Preoperative assessment

1. Exact regimen: drug, dose, route, frequency, breakthrough use — calculate approximate oral morphine equivalent (OME) if helpful.
2. Other CNS depressants: benzodiazepines, gabapentinoids, alcohol, cannabis — respiratory depression synergy.
3. OUD treatment: methadone, buprenorphine (± naloxone), naltrexone implants/oral — need specialist plans.
4. Pain psychology, sleep, mood, functional goals.
5. Surgery magnitude and regional opportunities.
6. Monitoring destination if high OME or OSA risk.
7. APS referral early for complex regimens. [1]

Core principle: continue baseline

Abrupt cessation causes withdrawal + uncontrolled pain. Convert usual daily opioid into perioperative baseline (oral if absorbing; otherwise IV infusion/PCA baseline strategy per local protocol). Then treat surgical pain on top.[1]

Multimodal stack (build high)

Layer rather than chase with morphine alone: [1]

• Paracetamol regular.
• NSAID/COX-2 if renal, bleed, anastomosis, and CV risk allow.
• Regional / neuraxial / fascial plane / catheter techniques when indicated (LAST readiness).[2][3]
• Ketamine low-dose infusion (common tolerant-patient adjunct).
• Alpha-2 agonists (clonidine/dexmedetomidine) carefully — sedation/hypotension.
• Gabapentinoids: selective, not automatic (sedation, dizziness, respiratory concerns with opioids).
• Local infiltration / surgical catheters.
• Non-pharmacological: ice, positioning, explanation, expectation setting.

Regional techniques are high-value in tolerant patients because they reduce reliance on escalating systemic opioids.[1]

PCA adjustments

Standard opioid-naive PCA settings under-dose tolerant patients. [1]

Document the plan so night staff do not “reset to naive defaults”. [1]

Special pharmacologies (principles, not cookbook)

Methadone: long QT, complex kinetics — continue usual dose when possible; add other acute analgesics; ECG awareness. [1]

Buprenorphine: high-affinity partial agonist — continue in many modern pathways for surgery with additional full-agonist and multimodal cover, or modify with addiction medicine/APS advice (local protocols vary — state principles and escalate). [1]

Naltrexone: antagonist — elective surgery may need timed cessation under specialist advice; emergency care is difficult analgesia planning. [1]

Intrathecal pumps: coordinate with pain specialist; do not manipulate reservoirs casually. [1]

Anaesthetic goals

1. Continue baseline opioid equivalents.
2. Maximise non-opioid and regional analgesia.
3. Provide adequate acute opioid with monitoring.
4. Prevent withdrawal.
5. Involve APS.
6. Discharge with taper and follow-up — not a new chronic high dose. [1]

Intraoperative management

• Give baseline equivalent early (IV titration if NBM).
• Prefer regional as primary analgesic when surgery matches.
• Ketamine bolus/infusion common.
• Avoid pure “remifentanil only then nothing” without transition plan.
• FULL reversal of neuromuscular block; avoid residual weakness mislabelled as opioid sedation.
• LAST kit if large-volume fascial blocks.[2]

Postoperative / acute-on-chronic

Expect higher opioid need than naive peers. Reassess: block failure, surgical complication, compartment syndrome, urine retention, anxiety — do not only escalate opioids. Use functional goals (deep breathe, mobilise) not pain score alone. APS rounds for complex OME, methadone/buprenorphine, or failed plans. [1]

Discharge

• Wean acute escalations toward baseline over days.
• Avoid discharging on higher long-term OME without a named taper owner.
• Naloxone education when high-dose home opioids and risk factors coexist (local practice).
• Communicate with GP/pain clinic.
• Constipation and antiemetic plans. [1]

Crisis pivots

Severe pain in PACU

Check block, surgical problem, full bladder, anxiety; give titrated IV opioid on top of baseline; start ketamine/regional rescue; do not argue about “drug seeking” in immediate recovery. [1]

Respiratory depression

ABC, oxygen, airway support, titrated naloxone (avoid full precipitated withdrawal if possible), stop backgrounds, monitored bed, review polypharmacy. [1]

Withdrawal

Sweating, tachycardia, agitation, myalgias, GI upset — reinstate opioid baseline, supportive care; differential includes sepsis and delirium. [1]

Suspected diversion / behavioural conflict

Treat acute pain; involve APS and, if needed, addiction services; clear boundaries with consistent team messaging — not unilateral punishment on the night shift. [1]

SAQ answer scaffold

A 52-year-old taking oxycodone 40 mg BD and amitriptyline for chronic back pain needs L4–5 decompression. Outline perioperative analgesia. [1]

1. Assessment (3): total OME, other sedatives, OUD features, regional opportunity, APS.[1]
2. Baseline (2): continue equivalent perioperatively.
3. Multimodal/regional (4): paracetamol/NSAID if safe, wound/local/regional options, ketamine.[3]
4. PCA (2): escalated settings, monitoring, no casual ward background.
5. Discharge (2): taper plan, GP/pain clinic communication.

Viva stem bank and model phrases

Stem 1: “Do you stop their morphine pre-op?”
Model: “No — I continue baseline opioid to prevent withdrawal and uncontrolled pain, then treat surgical pain on top.” [1]

Stem 2: “PCA same as everyone?”
Model: “No — tolerant patients need individualised higher settings with monitoring and APS involvement.” [1]

Stem 3: “Are they addicted so we minimise opioids?”
Model: “Tolerance and OUD are not reasons to deny acute analgesia. I use multimodal and regional aggressively and dose opioids safely.” [1]

Stem 4: “Role of ESP or other plane blocks?”
Model: “Fascial plane techniques can reduce systemic opioid need as part of multimodal care — with ultrasound and LAST readiness.”[3][2]

Stem 5: “Background PCA infusion?”
Model: “Only with appropriate monitoring; unmonitored ward backgrounds are a classic respiratory arrest risk.” [1]

Stem 6: “Buprenorphine patient for emergency laparotomy?”
Model: “I involve APS/addiction medicine early, continue or modify per protocol, maximise regional/multimodal, and accept that full-agonist requirements may be high.” [1]

Stem 7: “Discharge script triple their usual dose?”
Model: “That is a failure mode. I aim to return toward baseline with a named taper and follow-up.” [1]

Common traps

• Stopping baseline opioids
• Naive PCA defaults
• Unmonitored background infusions
• Moralising / withholding
• No regional attempt when anatomy allows
• New chronic high-dose discharge
• Missing withdrawal vs sepsis
• Ignoring benzodiazepine co-prescription risk [1]

[1] [1] [1]

Worked conversion sketch (principles only)

State method when converting between opioids: use a recognised equianalgesic table, apply a dose reduction for incomplete cross-tolerance (commonly 25–50% when switching), then titrate. Do not treat online calculators as law for methadone or buprenorphine — those need specialist advice. Write both the oral baseline and the IV rescue plan on the chart so night staff share one mental model. [1]

Regional opportunities by surgery type

Spine decompression: wound catheters, careful with prior spine anatomy. Laparotomy: TAP/QL/ESP plus multimodal. TKA: adductor canal + local infiltration. Thoracotomy: paravertebral/ESP/epidural as expertise allows. Always include LAST maths when volumes climb.[2][3]

Communication scripts that prevent conflict

"Your usual pain medicines will continue so you do not go into withdrawal; surgery pain is extra and we will treat it with several methods including nerve blocks where safe; the goal is function — breathing and walking — not a zero pain score; we will step back toward your usual dose before home." That script scores in vivas and wards alike. [1]

Examiner mental map

1. Define tolerance vs OUD without stigma.
2. Continue baseline opioid.
3. Multimodal + regional stack.
4. PCA individualisation and monitoring.
5. Special drugs (methadone/buprenorphine/naltrexone) — escalate.
6. Discharge taper ownership. [1]

That is consultant APS thinking in six steps. [1]

References

1. [1]Chou R, Gordon DB, de Leon-Casasola OA, et al. Management of Postoperative Pain: A Clinical Practice Guideline From the American Pain Society, the American Society of Regional Anesthesia and Pain Medicine, and the American Society of Anesthesiologists' Committee on Regional Anesthesia, Executive Committee, and Administrative Council J Pain, 2016.PMID 26827847
2. [2]Neal JM, Barrington MJ, Fettiplace MR, et al. The Third American Society of Regional Anesthesia and Pain Medicine Practice Advisory on Local Anesthetic Systemic Toxicity: Executive Summary 2017 Reg Anesth Pain Med, 2018.PMID 29356773
3. [3]Forero M, Adhikary SD, Lopez H, Tsui C, Chin KJ. The Erector Spinae Plane Block: A Novel Analgesic Technique in Thoracic Neuropathic Pain Reg Anesth Pain Med, 2016.PMID 27501016