Review Article

Development of a Multimodal Analgesia Protocol for Perioperative Acute Pain Management for Lower Limb Amputation

Table 4

Perioperative multimodal acute pain management protocol for lower limb amputation (LLA).

PhaseFocusMultimodal pain managementCommentsPrecautions/references

PreoperativeAssess and treat acute or chronic pain before surgery. Optimize an analgesic regime based on the patient’s condition.Principle components: Oral +/− parenteral opioids intravenous piggyback (IVPB), or patient-controlled analgesia (PCA), acetaminophen, NSAIDs. Adjuvants: gabapentinoids, antidepressantsConsult the acute pain service (APS) if the patient has:
 (i) Chronic pain issues requiring high dose opioid
 (ii) A complex pain management regime
 (iii) Standard analgesics ordered that are ineffective
Aggressive and early treatment of pain is needed to mitigate the severity of chronic limb pain [9, 12, 19, 42, 43]

IntraoperativePerineural (CPNB) “stump” catheter surgically placed:
 (i) Below the knee amputation (posterior tibial nerve)
 (ii) above the knee amputation (sciatic nerve)
Principle components:
(1) Regional anesthesia CPNB catheter:
 (i) Bolus with local anesthetic (bupivacaine 0.25%, 10–20 mL) before wound closure, volume dependent on patient size
(2) Opioids: intraoperative opioids as needed
For CPNB infusions:
 (i) Use only nonepinephrine solutions of local anesthetic: (bupivacaine 0.125–0.25%, or ropivacaine 0.1–0.5%)
APS is contacted for all issues related to the CPNB catheter (i.e., disconnection, choice to continue or remove the CPNB catheter) [26, 28]

Postoperative day 0-1Control residual limb pain (RLP). Maintain the preexisting analgesic regime. Prevent opioid withdrawal.Principle components:
(1) Regional anesthesia CPNB infusion:
Drug & concentration:
 (i) Bupivacaine 2.5 mg/mL (2.5% in 250 mL normal saline) or
 (ii) Ropivacaine 2 mg/mL (2.0% in 100 mL normal saline, recommended with renal dysfunction)
Dosing parameters:
 (i) Continuous infusion 4–10 mL/hr
 (ii) Start at 5–6 mL/hr, increase by 2 mL/hr at a time every 2 hours (up to 10 mL/hr) if pain persists
(2) Opioids:
 (i) Oral +/− parenteral opioids (IVPB or PCA) for breakthrough pain
 (ii) Oral opioids (short acting) for opioid-naive patients: oxycodone, morphine, hydromorphone
 (iii) Commonly used: oxycodone 5–10 mg p.o. q3-4 h PRN or oxycodone 2.5–5 mg p.o. q3-4 h PRN (frail older adult, renal impairment)
(3) Nonopioid analgesics:
 (i) Acetaminophen 500–1000 mg p.o. q6 h
 (ii) NSAIDs: Ibuprofen 200–400 mg p.o. q6 h or Ketorolac 10 mg IVPB q6 h or Celebrex 100 mg p.o. BID Adjuvants:
 (i) Gabapentinoids: gabapentin or pregablin
 (ii) Antidepressants
APS follows patients with CPNB infusions and orders all analgesics, antipruritics, antiemetics, and sedating medications.
Usually no patient-controlled bolus dose is needed. But if ordered, suggest:
 (i) Bolus dose 2–4 mL
 (ii) Lockout 20–30 minutes. Adjust opioid doses for patients already on substantial doses of opioids preoperatively.
 (i) Continue long-acting opioids for opioid-tolerant patients.
 (ii) Use parenteral opioids for severe pain not controlled by CPNB infusion and oral analgesics.
 (iii) Consider PCA if this was used preoperatively or if systemic opioids are required for more than a few hours postoperatively.
Acetaminophen ordered around-the-clock for 2–5 days with dosage adjustments after 2-3 days.
Add NSAID only if renal function is adequate and there are no other contraindications (e.g., active or previous ulcer disease, systemic anticoagulation, asthma, and congestive heart failure).
Resume adjuvants if already established on these agents preoperatively.
Notify APS if the patient complains of persistent pain (>5/10) not relieved with an increase in CPNB infusion rate or other analgesics ordered. CPNB catheter may require a repeat bolus of local anesthetic (as intraoperatively) [27, 28, 46, 47]
Protect the affected limb for the duration of CPNB infusion to prevent injury or pressure sores as “numbness” is common (e.g., avoid placing laptop computers, cold or hot packs on areas of skin with decreased sensitivity).
Choice of opioid and dosing determined by patient’s preoperative opioid requirements, age, hepatic, and renal function [51]
Start opioids at low dose and gradually increase to provide adequate pain relief with tolerable side effects [24, 25, 39, 50, and 53]
Risk of acetaminophen for hepatotoxicity: maximum daily dose 4000 mg, less for debilitated patients [24, 25]
Long-term use of NSAIDs is not recommended due to GI and renal toxicity. Celebrex is a possible alternative to traditional NSAIDs [3, 9, 25]
Reduce dose of gabapentinoids with renal dysfunction or if side effects ensue (sedation, drowsiness) [10, 30, 53]

Postoperative day 2–3Assess and aggressively treat residual limb pain (RLP) and phantom limb pain (PLP).Principle components: (1) Regional anesthesia CPNB catheter:
 (i) Continue infusion
(2) Opioids: discontinue PCA
 (i) Unless pain intensity remains severe (>5/10)
 (ii) Transition to oral opioid with IVPB opioid rescue dose PRN
(3) Nonopioid analgesics:
 (i) Acetaminophen: reduce dose to 500–650 mg q6 h
 (ii) NSAIDs: continue PRN Adjuvants:
(1) Consider initiating:
 (i) Gabapentin 100–300 mg p.o. BID to TID, increasing dose every 2–3 days to a maximum of 2400–3600 mg/day, if needed or
 (ii) Pregabalin 50–75 mg p.o. daily, increasing dose to BID after one week, to a maximum dose of 150 mg BID if needed
(2) Continue antidepressants
Adjust CPNB infusion rate and opioid doses along with adjuvant agents to provide adequate pain relief.
Initiate gabapentinoid gradually for patients with significant RLP and PLP issues not relieved by CPNB infusion and the “usual” analgesic regime. This may be effective in reducing opioid requirements.
Only use parenteral opioids (IVPB or PCA) in the early postoperative phase to manage pain. Switch to oral opioid as soon as possible [25]
Use nonopioid analgesics cautiously in older or frail patients (>65 years), OSA, and renal dysfunction. Lower initial doses with slow titration to manage side effects of dizziness, sedation, and tolerability. Monitor renal function [54]
If considering initiating a trial of a new adjuvant, do so only gradually [53]
[11, 21, 24, 30, 34]

Postoperative day 3-4Pain management coordinated with increased activityMaintain CPNB infusion and multimodal analgesia.Consider consulting the chronic pain service for optimizing a long-term pain management plan.Initiate early plans for the eventual analgesic regime, especially for complex pain patients [42, 43]

Postoperative day 5Discontinue CPNB catheterCPNB catheter removed with initial dressing change to the residual limb (unless ordered for a longer duration by the anesthesiologist or if requested by the vascular surgery team)Maximum period of time for CPNB catheter to remain in place: 7 days [27, 28, 47, 48]Gradually wean patient off opioid and nonopioid analgesics. Adjust adjuvant doses with the overall goal of reduction and/or eventual discontinuation

Postoperative day 6 and followingManagement of persistent pain and/or phantom limb pain (PLP), if presentContinue multimodal analgesia agents (not including the CPNB catheter) at lowest possible doses.Treat persistent pain like neuropathic pain. [18, 30, 34, 53]
Reconsider consulting the chronic pain service.
Currently there are no consensus guidelines for the optimal management of chronic PLP [10, 11, 13, 15, 16, 2022, 39]

IVPB, intravenous piggyback; PCA, patient-controlled analgesia; APS, acute pain service; CPNB, continuous peripheral nerve block; RLP, residual limb pain; NSAID, nonsteroidal anti-inflammatory drug; GI, gastrointestinal; PLP, phantom limb pain; OSA, obstructive sleep apnea.