What is the recommended postoperative multimodal analgesia approach for a patient with Rheumatoid Arthritis (RA)?

Postoperative Multimodal Analgesia in Rheumatoid Arthritis

For patients with RA undergoing surgery, implement a multimodal analgesic regimen consisting of scheduled acetaminophen, NSAIDs or COX-2 inhibitors (with careful cardiovascular and renal assessment), intravenous dexamethasone 8-10 mg intraoperatively, procedure-specific regional anesthesia, and reserve opioids strictly for breakthrough pain. 1

Core Pharmacological Foundation

The foundation of postoperative analgesia in RA patients must include:

• Acetaminophen 1000 mg every 6 hours scheduled - This reduces opioid consumption by approximately 22 mg morphine equivalents and should be started preoperatively or intraoperatively and continued postoperatively 1, 2

• NSAIDs or COX-2 selective inhibitors - These provide superior pain relief with opioid-sparing effects and are particularly important in RA patients given their familiarity with these medications 1, 3. However, you must evaluate cardiovascular risk, renal function, hepatic function, bleeding risk, and GI ulcer history before administration 4

• Intravenous dexamethasone 8-10 mg as a single intraoperative dose - This provides both analgesic and anti-emetic effects with well-documented safety 1. The safety of a single dose is established, and equipotent doses of alternative glucocorticoids are equally effective 1

Procedure-Specific Regional Techniques

For orthopedic procedures common in RA patients:

• Total hip arthroplasty: Use fascia iliaca block or local infiltration analgesia as the primary regional technique 1. Femoral nerve blocks, lumbar plexus blocks, and epidural analgesia are not recommended due to better and safer alternatives now available 1

• Total knee arthroplasty: Femoral nerve blocks significantly reduce pain scores at 24-48 hours during movement/physical therapy (weighted mean difference -15.07mm at 24h, p=0.002) 1, 2

• Intrathecal morphine 0.1 mg can be considered if spinal anesthesia is used, but recognize the controversy: it provides 24-hour analgesia but causes pruritus and postoperative nausea/vomiting that may delay ambulation 1. Modern multimodal analgesia with acetaminophen, NSAIDs, and dexamethasone may provide sufficient pain relief without intrathecal morphine 1

Opioid Management Strategy

Minimize opioid use aggressively - This is critical in all postoperative patients but especially important given RA patients may already be on chronic pain medications 1:

• Reserve opioids strictly as rescue analgesics for breakthrough pain only 1
• Use patient-controlled analgesia (PCA) if IV route is needed in cognitively intact patients 1, 2
• Implement prophylactic bowel regimen when opioids are administered 4
• Monitor respiratory rate and sedation level every 2-4 hours for the first 24-72 hours 2
• Taper opioids rapidly, avoiding use beyond 5-7 days, while continuing the non-opioid multimodal regimen 2

Adjunctive Considerations

Gabapentinoids (gabapentin or pregabalin) receive mixed recommendations:

• Emergency surgery guidelines give a moderate recommendation for their use in multimodal analgesia 1
• However, orthopedic surgery guidelines do not recommend gabapentinoids for hip arthroplasty due to sedation, blurred vision, dizziness, interference with early mobilization, and orthostatic intolerance 1
• Decision point: Use gabapentinoids only if the patient has neuropathic pain components or is at very high risk for severe postoperative pain, and only if early mobilization is not a priority 1

Critical Pitfalls in RA Patients

NSAID contraindications are more common in RA patients - Many have cardiovascular disease, renal impairment, or are on anticoagulation 4. When NSAIDs are contraindicated, increase reliance on regional techniques and consider COX-2 selective inhibitors if cardiovascular risk permits 1

Pre-existing opioid use - RA patients with chronic pain may already be opioid-tolerant. Pre-operative opioid use is the strongest predictor of persistent postoperative opioid use (up to 10-fold increased risk), and doses ≥60 mg oral morphine equivalents daily pre-operatively confer 80% probability of persistent use 4. For these patients, calculate equianalgesic doses and start with half the calculated dose when converting 4

Drug interactions with DMARDs - While naproxen can be used safely with gold salts and corticosteroids, avoid combining NSAIDs with aspirin as this increases NSAID excretion rates and raises adverse event frequency 3

Avoid ketamine and epidural analgesia - Ketamine is not recommended due to limited procedure-specific evidence and psychotropic side-effects 1. Epidural analgesia for hip arthroplasty is not recommended as adverse effects outweigh benefits 1

Monitoring and Reassessment Protocol

Establish 24-hour monitoring with regular pain assessment at standardized intervals 1:

• Assess pain scores at rest and with movement 2
• When significant worsening pain is reported, reevaluate for postoperative complications 1
• A combined nurse service with clinician supervision provides better outcomes 1