What opioid‑sparing multimodal analgesic plan is recommended for a 60‑80‑year‑old patient undergoing primary total knee arthroplasty who has hypertension, osteoarthritis, and mild renal or cardiac disease?

Opioid-Sparing Multimodal Analgesia for Total Knee Arthroplasty

For a 60-80 year-old patient with hypertension, osteoarthritis, and mild renal or cardiac disease undergoing primary total knee arthroplasty, implement general anesthesia combined with adductor canal block (preferred over femoral nerve block for motor-sparing benefits), supplemented with scheduled acetaminophen, NSAIDs/COX-2 inhibitors (with renal/cardiac monitoring), single-dose dexamethasone, and reserve opioids strictly for breakthrough pain. 1, 2

Primary Anesthetic Technique

Choose one of these evidence-based approaches:

• General anesthesia + adductor canal block (preferred for this population as it preserves quadriceps strength while providing excellent analgesia) 1, 2
• Alternative: Spinal anesthesia with local anesthetic + intrathecal morphine 0.1 mg (provides 24-hour analgesia but monitor closely for respiratory depression in elderly patients) 3, 1, 2

For extended postoperative analgesia, use continuous adductor canal block catheter rather than single-shot injection 1

Scheduled Multimodal Baseline Regimen

Administer these medications on a fixed schedule, NOT as-needed:

• Acetaminophen 1g every 6 hours (maximum 4g/day; reduce dose if significant hepatic impairment) 1, 4, 5
• NSAIDs or COX-2 selective inhibitors - but exercise caution in this population 3, 1, 5:
  • If mild renal disease (eGFR 45-60): Use lowest effective dose of celecoxib 200mg daily or ibuprofen 400mg every 8 hours with daily monitoring 4
  • If mild cardiac disease: Avoid NSAIDs entirely or use celecoxib (lowest cardiovascular risk) for maximum 48-72 hours only 4
  • If hypertension controlled: Monitor blood pressure closely as NSAIDs may interfere with antihypertensive efficacy 3
• Dexamethasone 8-10mg IV intraoperatively (single dose - provides analgesia and reduces nausea without significant adverse effects) 1, 4, 5

Rescue Analgesia Protocol

Reserve opioids strictly for breakthrough pain, NOT scheduled administration:

• High-intensity pain (VAS >70/100): IV morphine 0.025-0.1 mg/kg titrated to effect, or IV fentanyl 0.5-1 mcg/kg 1
• Moderate pain (VAS 40-70/100): Oral tramadol 50-100mg every 6 hours as needed (reduce dose by 20-25% due to age >60 years) 3, 1
• Low-intensity pain (VAS <40/100): Oral codeine 30-60mg every 4-6 hours as needed 3, 1

Critical age-based dosing: Reduce opioid doses by 20-25% per decade after age 55 to minimize adverse effects without compromising pain control 3

Adjunctive Non-Pharmacological Techniques

• Cooling and compression devices applied to the surgical site reduce inflammation and pain 3, 2
• Early mobilization protocols beginning postoperative day 1 3

What NOT to Do: Critical Contraindications

Avoid these interventions that lack evidence or carry excessive risk in this population:

• Do NOT use gabapentinoids (gabapentin/pregabalin) - cause sedation, dizziness, and orthostatic intolerance that interfere with early mobilization in elderly patients 3, 5
• Do NOT combine femoral + sciatic nerve blocks - no proven benefit over adductor canal block alone and increases fall risk 1
• Do NOT use epidural analgesia - increased serious adverse events without superior analgesia compared to peripheral nerve blocks 1
• Do NOT use intra-articular local anesthetics, morphine, clonidine, or corticosteroids - inconsistent evidence of efficacy 1
• Do NOT prescribe modified-release opioids or transdermal patches at discharge 1
• Do NOT exceed 5-7 days of opioid prescriptions at discharge 1

Special Monitoring Considerations for This Population

Given the comorbidities, implement these safeguards:

• Renal function: Check baseline creatinine; if using NSAIDs with eGFR 45-60, recheck creatinine at 48 hours and discontinue if rising 4
• Cardiac status: Continuous telemetry for first 24 hours if using intrathecal morphine (respiratory depression risk) 3
• Hypertension: Monitor blood pressure every 4 hours for first 48 hours when using NSAIDs 3
• Opioid-related monitoring: Assess sedation level and respiratory rate every 2 hours when administering rescue opioids in patients >65 years 3

Common Pitfalls to Avoid

• Pitfall: Administering acetaminophen and NSAIDs "as needed" rather than scheduled - this causes fluctuating drug levels and inadequate baseline analgesia 3
• Pitfall: Using full-dose bilateral nerve blocks if bilateral surgery - reduce total local anesthetic dose by 30-40% to prevent systemic toxicity 1
• Pitfall: Continuing NSAIDs beyond 48-72 hours in patients with cardiac disease - cardiovascular risk increases with duration 4
• Pitfall: Failing to reduce opioid doses in elderly patients - standard adult doses cause excessive sedation and respiratory depression in patients >60 years 3