What is the initial management of pain associated with sternal fractures?

Initial Management of Pain Associated with Sternal Fractures

Begin with scheduled acetaminophen 1000 mg every 6 hours as the foundation of pain control, combined with ultrasound-guided parasternal or subpectoral interfascial plane blocks for optimal analgesia and respiratory function. 1, 2, 3

First-Line Multimodal Analgesia

Non-Opioid Pharmacotherapy

• Administer acetaminophen 1000 mg IV or PO every 6 hours on a scheduled basis (not as-needed), with maximum daily dose not exceeding 4000 mg. 4, 1
• Add NSAIDs if no contraindications exist: ibuprofen 400-600 mg every 6-8 hours (maximum 2400 mg/day) or naproxen 500 mg twice daily. 4
• Exercise caution with NSAIDs in patients with renal dysfunction (GFR <60 mL/min/1.73m²), cardiovascular disease, or concurrent anticoagulation due to bleeding risk and cardiac toxicity. 4

Regional Anesthetic Techniques (Preferred)

Regional blocks provide superior analgesia compared to opioids alone and should be implemented early. 5, 2, 3

• Ultrasound-guided bilateral parasternal blocks deliver target-specific analgesia directly to the fracture site, improving ventilation mechanics and reducing pulmonary morbidity. 2
• Bilateral subpectoral interfascial plane catheters with continuous local anesthetic infusion provide sustained pain relief for patients intolerant to systemic opioids. 3
• Ultrasound-guided intercostal cryoneurolysis offers prolonged analgesia lasting several weeks, reduces opioid requirements, and improves mobilization—particularly valuable for transverse sternal fractures requiring treatment of only four intercostal nerves. 6
• Implement regional techniques early (within hours of presentation) rather than delaying, as timing significantly impacts outcomes. 5, 1

Opioid Therapy (Reserved for Breakthrough Pain)

Initial Dosing

• Morphine sulfate IV 0.1-0.2 mg/kg (typically 5-10 mg) administered slowly every 4 hours as needed for breakthrough pain uncontrolled by non-opioid strategies. 7
• Administer as slow IV push to avoid chest wall rigidity; rapid administration is contraindicated. 7
• Have naloxone and resuscitative equipment immediately available. 8, 7

Opioid Selection and Alternatives

• Morphine sulfate oral 20-40 mg every 4 hours if transitioning from IV (oral bioavailability requires 2-3 times higher dose). 4
• Oxycodone oral 20 mg provides 1.5-2 times the potency of oral morphine. 4
• Tramadol 50-100 mg every 4-6 hours (maximum 400 mg/day) for moderate pain. 4

Critical Opioid Precautions

• Reduce initial opioid doses by 50% in elderly patients (>60 years) and those with hepatic or renal impairment, titrating slowly while monitoring for respiratory depression and sedation. 4, 1, 7
• Monitor respiratory rate, oxygen saturation, and sedation level continuously. 8, 1
• Reassess pain scores 15-30 minutes after each dose to determine effectiveness. 8, 1
• Both inadequate analgesia and excessive opioid use increase delirium risk in elderly patients—balance is essential. 1

Monitoring and Assessment

Respiratory Function

• Obtain arterial blood gas analysis if altered chest mechanics or hypoventilation suspected, as sternal fractures impair respiratory mechanics. 2
• Consider pulmonary electrical impedance tomography to identify regional hypoventilation patterns. 2
• Pain preventing deep breathing and coughing predisposes to chest infections—aggressive analgesia is protective. 3, 9

Pain Assessment

• Document pain scores at rest and with movement before and after analgesia administration. 4
• Use age-appropriate pain scales; consider alternative scoring systems for patients with cognitive dysfunction. 4, 8

Adjunctive Interventions

Non-Pharmacological Measures

• Implement proper positioning and immobilization techniques for the injured sternum. 1
• Apply ice packs to the affected area in conjunction with pharmacological therapy. 1

Surgical Fixation Consideration

Sternal fixation significantly improves pain (average reduction of 3.5 points on pain scale), decreases narcotic requirements by 7.59 morphine milligram equivalents, and restores upper extremity range of motion. 10

• Consider surgical fixation for patients with intractable pain despite optimal medical management, constant fracture movement limiting function, or inability to perform activities of daily living. 10
• Surgery provides definitive pain relief and accelerates return to normal activities. 4, 10

Common Pitfalls to Avoid

• Do not routinely admit patients with isolated sternal fractures for observation alone—this practice is often unnecessary if concomitant injuries are excluded and adequate outpatient analgesia established. 9
• Avoid relying solely on opioids without regional techniques or scheduled non-opioid analgesics, as this approach provides inferior pain control and increases adverse effects. 5, 2, 3
• Never administer morphine rapidly IV—slow administration is mandatory to prevent chest wall rigidity. 7
• Systematically evaluate for concurrent chest injuries (rib fractures, pulmonary contusions, cardiac injuries), as mortality increases dramatically with associated injuries. 3, 9
• Do not exceed maximum safe doses: acetaminophen 4000 mg/day, ibuprofen 2400 mg/day, naproxen 1000 mg/day. 4, 1