What can be given next to a postoperative knee pain patient currently on Po (Percocet) Norco 10 (hydrocodone and acetaminophen) and morphine 2 mg?

Next-Line Analgesia for Postoperative Knee Pain

Add intravenous ketorolac 0.5-1 mg/kg (up to 30 mg) as the next immediate intervention, followed by scheduled paracetamol (acetaminophen) if not already administered. 1, 2

Immediate Rescue Analgesia

First-Line Addition: IV Ketorolac

• Administer IV ketorolac 0.5-1 mg/kg (maximum 30 mg single dose) as it significantly reduces morphine requirements by 26% when used as an adjunct to opioids 2
• For continued pain management, ketorolac 0.15-0.2 mg/kg (max 10 mg) can be given every 6 hours for short-term therapy (maximum 48 hours) 1
• Ketorolac provides superior analgesia when combined with PCA morphine compared to morphine alone 2

Second-Line: Scheduled Non-Opioid Analgesics

• Start scheduled paracetamol (acetaminophen) 10-15 mg/kg every 6 hours (maximum daily dose 60 mg/kg) if not already prescribed 1
• Paracetamol is recommended in combination with other analgesics as it reduces supplemental analgesic use in orthopedic procedures 1, 3
• Paracetamol should be given on a scheduled basis, not as-needed 3

Additional Opioid Rescue Options

For Persistent High-Intensity Pain

• Increase morphine dose or frequency via IV titration: 25-100 micrograms/kg depending on age, titrated to effect 1
• Consider IV fentanyl 0.5-1.0 micrograms/kg, titrated to effect, for breakthrough pain 1
• Strong opioids are recommended for high-intensity pain when non-opioid analgesia is insufficient 1, 3

For Moderate-Intensity Pain

• IV tramadol 1-1.5 mg/kg can be used for moderate pain, titrated to effect 1
• Weak opioids are recommended in combination with non-opioid analgesics for moderate or low-intensity pain 1

Multimodal Optimization

Add COX-2 Inhibitors or NSAIDs

• Add conventional NSAIDs or COX-2-selective inhibitors unless contraindicated (renal impairment, bleeding risk, cardiovascular disease) 1, 3
• Alternative NSAIDs include ibuprofen 10 mg/kg every 8 hours or ketoprofen 1 mg/kg every 8 hours 1

Consider Adjunctive Ketamine

• Low-dose IV ketamine 0.5 mg/kg (or 0.25-0.5 mg/kg for S-ketamine) may be used as an adjunct, titrated to effect 1
• Ketamine should only be used as part of multimodal analgesia, never as monotherapy 4

Critical Pitfalls to Avoid

What NOT to Do

• Do NOT prescribe modified-release opioid preparations (including transdermal patches) without specialist consultation 1
• Avoid intra-articular morphine or local anesthetic as there is inconsistent evidence of analgesic efficacy for postoperative knee pain 1, 3
• Do not use weak opioids as monotherapy for high-intensity pain - they are inadequate for severe postoperative knee pain 1
• Avoid epidural analgesia due to increased risk of serious adverse events without superior benefits 3, 4

Discharge Planning Considerations

• Prescribe no more than 5-7 days of opioids (including tramadol) at discharge 1
• Prescribe opioid and non-opioid analgesics separately to allow for individual dose adjustments 1
• Ensure the discharge letter explicitly states the recommended opioid dose, amount supplied, and planned duration of use 1

Regional Anesthesia Consideration

If Pain Remains Uncontrolled

• Consider adductor canal block or femoral nerve block if not already performed, as these provide superior analgesia and reduce supplemental analgesic requirements 1, 3
• Continuous adductor canal block catheter technique is preferred over single-shot injection for extended analgesia 3
• Femoral nerve block is the gold standard regional technique with Grade A evidence for reducing pain scores and supplemental analgesia 1