What is the management and workup for a patient with a retrosternal hematoma and sternal fracture?

Management and Workup of Retrosternal Hematoma with Sternal Fracture

Patients with sternal fracture and retrosternal hematoma require immediate ECG and cardiac troponin assessment, CT chest imaging, and close monitoring for cardiac complications, as retrosternal hematoma significantly increases the risk of concomitant injuries and can rarely cause life-threatening extra-pericardial cardiac tamponade. 1, 2, 3

Immediate Assessment and Risk Stratification

Initial Diagnostic Workup

• Obtain baseline 12-lead ECG and cardiac troponin levels immediately upon presentation, as these are mandatory tests for all sternal fractures and allow safe discharge only when both are normal 1, 4, 5
• Perform CT chest without IV contrast using sagittal and 3-D reconstructions as the imaging modality of choice to accurately detect sternal fracture characteristics, quantify retrosternal hematoma, and identify concomitant injuries 1, 5
• Assess for hemodynamic instability (systolic BP <90 mmHg, heart rate >100 bpm, shock index >1) as this may indicate ongoing bleeding or cardiac compromise 6

High-Risk Features Requiring Intensive Monitoring

The presence of retrosternal hematoma carries a 5.35-fold increased odds of concomitant injury compared to sternal fractures without hematoma 3. Specifically assess for:

• ECG abnormalities (particularly widespread T-wave inversions, ST changes, or arrhythmias) indicating possible myocardial contusion or acute coronary syndrome 5
• Rising cardiac troponin levels suggesting myocardial injury, which occurs in approximately 6% of sternal fracture patients 1
• Manubrium fractures, which carry a 6.85-fold increased odds of concomitant injury compared to body fractures 3
• Signs of extra-pericardial cardiac tamponade (rare but life-threatening): hypotension, jugular venous distension, muffled heart sounds, or pulsus paradoxus 2

Critical Pitfall to Avoid

Retrosternal hematoma can cause extra-pericardial cardiac tamponade without pericardial fluid collection, compressing the heart externally—this requires extremely high clinical suspicion and urgent surgical evacuation if present 2. Standard echocardiography may miss this diagnosis; CT imaging is more effective 2.

Admission Criteria and Monitoring Strategy

Patients Requiring Hospital Admission

Admit patients with any of the following 1, 5, 7:

• Abnormal ECG or elevated/rising cardiac troponins → telemetry monitoring for minimum 6-12 hours with serial biomarkers 5
• Retrosternal hematoma on CT → higher risk of concomitant injuries requiring observation 3
• Hemodynamic instability despite initial resuscitation 6
• Displaced sternal fractures or complex analgesic requirements 7
• Significant concomitant injuries: rib fractures (present in 56.7% of sternal fractures), vertebral fractures (38.2%), pulmonary contusions, or other thoracic injuries 8, 3
• Geriatric patients (>65 years) who have 12.9% mortality rate and require fall risk assessment, osteoporosis evaluation, and DVT prophylaxis 1, 8

Patients Safe for Discharge

Only discharge if ALL criteria met 1, 4:

• Normal ECG and normal cardiac troponins at presentation
• No retrosternal hematoma or minimal hematoma without hemodynamic concerns
• No concomitant injuries on CT
• Pain adequately controlled with oral analgesics
• Reliable follow-up arranged

Management of Concomitant Injuries

Cardiac Complications

• If ECG shows widespread T-wave inversions: Treat as possible NSTEMI with aspirin 162-325 mg, antiplatelet therapy, anticoagulation per ACC/AHA guidelines, and consider early invasive strategy 5
• If troponins elevated: Continue telemetry monitoring, serial biomarkers every 3-6 hours, and consider stress testing within 72 hours before discharge 5
• Echocardiography is NOT routinely indicated if ECG and troponins are normal for isolated sternal fractures 1, 4, 5

Hemorrhage Control (If Hemodynamically Unstable)

While rare with isolated sternal fractures, if patient develops shock:

• Initiate damage control resuscitation with tranexamic acid 1g IV over 10 minutes (within 3 hours of injury), followed by 1g over 8 hours 6
• Target systolic BP 80-100 mmHg until major bleeding controlled (permissive hypotension) in absence of traumatic brain injury 6
• Consider REBOA (Resuscitative Endovascular Balloon Occlusion of the Aorta) as bridge to definitive hemorrhage control if life-threatening bleeding 6
• Surgical evacuation of hematoma is the sole definitive treatment for mediastinal hematoma causing tamponade 2

Pain Management and Rehabilitation

Analgesia Strategy

• Provide multimodal analgesia tailored to patient comorbidities (NSAIDs, acetaminophen, opioids as needed) for adequate pain control essential for respiratory mechanics 1, 5
• Consider ultrasound-guided hematoma block for immediate and effective pain control in the emergency department, allowing safer analgesia and more rapid discharge in selected cases 9

Early Mobilization Protocol

• Begin early mobilization and physical therapy as soon as pain allows, typically within 24-48 hours 1, 5
• Start range-of-motion exercises for shoulder, elbow, wrist, and hand within first postoperative days 1
• Restrict above-chest-level activities until fracture healing evident (typically 6 weeks) 1, 4

Special Populations

Geriatric Patients (≥65 years)

Geriatric patients account for 50% of sternal fractures and have significantly higher mortality 8. Additional management includes:

• Assess for underlying osteoporosis and consider calcium/vitamin D supplementation 1, 4
• Perform fall risk assessment as part of overall management 1
• Monitor for DVT in less mobile patients with prophylactic anticoagulation 1
• Obtain vitamin D, calcium, and comprehensive metabolic panel before initiating supplementation 4

Follow-Up at 5 Days Post-Injury

If initial workup was normal, no additional laboratory testing is needed unless new symptoms develop 4. Focus should shift to:

• Pain management optimization with oral analgesics 4
• Physical therapy progression and early mobilization 1, 4
• Monitoring for delayed complications: new chest pain, dyspnea, or palpitations warrant immediate repeat ECG and serial troponins 4

Key Clinical Pearls

• 88% of sternal fracture patients do not require parenteral analgesia or procedures necessitating admission if isolated injury with normal cardiac workup 7
• Combined sternal fractures (with other injuries) occur in 82.1% of cases and carry 9.3% mortality versus 0% for isolated fractures 8
• Motor vehicle accidents are associated with lower odds of concomitant injury compared to other mechanisms 3
• Routine "trauma panels" at 5 days post-injury represent unnecessary testing for isolated, nondisplaced fractures 4