血液疾病的疼痛處置

Buzzwords → Dx

Workup

• Pain assessment: location, character, intensity (VAS/NRS), temporal, radiation, alleviating/exacerbating, functional impact.
• History: prior opioid use, OUD risk, allergies, comorbidities (renal, hepatic, GI, respiratory).
• Labs: BMP, LFTs (drug metabolism + dose adjustment).

Treatment Algorithm

flowchart TD
  A[Pain assessment] --> B{Severity + type}
  B -- mild --> C[Acetaminophen + NSAID<br>± adjuvants per type]
  B -- moderate --> D[+ Weak opioid (codeine, tramadol)<br>or low-dose oxycodone / hydromorphone]
  B -- severe / chronic cancer --> E[Long-acting opioid + breakthrough<br>+ adjuvants for neuropathic / bone]
  B -- SCD VOC --> F[IV opioid PCA<br>+ IVF + warmth + spirometry<br>NOT meperidine]
  B -- neuropathic --> G[Gabapentin / pregabalin / duloxetine / TCAs<br>± opioid]
  B -- bone pain --> H[Bisphosphonate / denosumab + RT + opioid<br>radium-223 for prostate met]
  C --> I[Constipation prophylaxis stimulant + osmotic]
  D --> I
  E --> I
  F --> I
  G --> I
  H --> I
  I --> J{Adequate control?}
  J -- no --> K[Rotate opioid<br>methadone consult<br>regional anesthesia / nerve block<br>palliative care]

Pearls / Pitfalls

• Avoid meperidine in chronic pain or renal failure — norverbal metabolite accumulates → seizures, dysphoria.
• Codeine is a prodrug (CYP2D6 → morphine); ultra-rapid metabolizers can have toxicity at standard doses; poor metabolizers ineffective. Avoid in children for tonsillectomy/adenoidectomy (FDA).
• Tramadol has serotonergic + opioid effects → SS risk with SSRIs; seizure risk; lower opioid-equivalent.
• Methadone has long, variable half-life + QT prolongation — use specialist guidance.
• Fentanyl patch onset is slow (12–18 h) + lasts 72 h — NOT for acute pain control.
• Buprenorphine + naloxone (Suboxone) for opioid use disorder — partial mu agonist; can complicate pain management; involve OUD specialist.
• NSAIDs caution: avoid in plt <50, active bleeding, CKD, peptic ulcer disease, recent GI bleed.
• Acetaminophen max 3 g/d (chronic) or 4 g/d (short-term); reduce in liver disease.
• Opioid-induced constipation is universal — start stimulant laxative (senna) + osmotic (polyethylene glycol) prophylactically.
• Opioid-induced respiratory depression treated with naloxone — short half-life (30–90 min) so re-dosing or infusion required for long-acting opioid overdose.
• Adjuvants for neuropathic pain: gabapentin / pregabalin (titrate slowly, sedation), duloxetine (also depression), nortriptyline (anticholinergic).
• Bone pain in MM: bisphosphonate (zoledronic acid / pamidronate) or denosumab + opioids + radiation; reduces fractures + pain.
• Cancer pain: undertreatment is common — assess + titrate aggressively. Most cancer pain is opioid-responsive; switch routes (IV → SC → PO) as functional status changes.
• Palliative care consultation for refractory pain, complex symptom management, psychosocial issues, end-of-life planning.
• SCD chronic pain: balance VOC management + chronic pain management; opioid stewardship critical with hydroxyurea / disease-modifying therapies.

Cross-references

• SCD VOC — opioid PCA
• MM — bone pain + bisphosphonates
• Cord compression — pain + dexamethasone
• Opioid-induced nausea
• Drug Regimens — opioids, adjuvants, chelators

相關題目

• Q-211 — Avoid meperidine in chronic pain
• Q-212 — Bone pain in MM — multimodal management
• Q-213 — Methadone — opioid rotation

Sources