📚 Guideline basis
ATLS eFAST protocol; ACEP/ASE focused cardiac ultrasound policy statements; 2022 ACC/AHA guideline for the diagnosis and management of aortic disease; Eastern Association for the Surgery of Trauma practice management guidelines on blunt cardiac injury.
The eFAST examination
Extended Focused Assessment with Sonography for Trauma answers binary questions about free fluid and air in five regions. It is a rule-in tool: a positive scan is highly actionable, a negative scan is not an exclusion.
Window | Probe position | Detects |
Pericardial (subxiphoid, or parasternal if subxiphoid fails) | Subxiphoid, aimed at the left shoulder | Haemopericardium |
Right upper quadrant (Morison's pouch) | Mid-axillary, 8th–11th intercostal | Hepatorenal free fluid — the most sensitive single abdominal window in the supine patient |
Left upper quadrant (splenorenal / subphrenic) | Posterior axillary, 6th–9th intercostal | Perisplenic and subphrenic fluid |
Pelvic (rectovesical / rectouterine) | Suprapubic, transverse and sagittal | Dependent pelvic fluid |
Thoracic (bilateral, anterior and lateral) | Anterior chest for sliding; posterolateral for effusion | Pneumothorax (absent sliding with a lung point) and haemothorax |
The eFAST detects free fluid, not organ injury. Solid organ injury without haemoperitoneum, retroperitoneal haemorrhage, hollow viscus perforation, and diaphragmatic rupture are all routinely missed. A negative eFAST in a haemodynamically unstable trauma patient does not exclude abdominal haemorrhage, and in the stable patient it does not obviate CT.
The pericardial window and its specific trap
Ultrasound is highly sensitive for haemopericardium in penetrating chest trauma and is the basis for the decision to proceed to thoracotomy or pericardial window. One failure mode matters:
A concurrent pericardial breach into the pleural space decompresses the pericardium. The patient with a penetrating injury exsanguinating through a torn pericardium into the left hemithorax has a normal-looking pericardial window and a massive haemothorax. Always examine the thoracic windows; a large haemothorax with a "reassuring" pericardium in penetrating precordial trauma is a surgical emergency, not a negative scan.
Conversely, in trauma, small volumes tamponade. The pericardium has had no time to stretch; 100–150 mL of rapidly accumulating blood produces full tamponade physiology while looking unimpressive on the image. Grade the physiology (chamber compression, plethoric IVC, falling output), not the volume.
Haemorrhagic shock — and the specific danger of misattribution
The echocardiographic signature of exsanguination is a small, hyperdynamic, cavity-obliterating left ventricle with a collapsed IVC — the same picture produced by any severe preload deficit.
The danger runs in the other direction. In a hypotensive trauma patient, echocardiography that shows "impaired left ventricular function" must be interpreted with extreme caution, because attributing hypotension to cardiac dysfunction rather than to haemorrhage delays transfusion and surgical control. Cardiac dysfunction in trauma is usually a consequence of hypoperfusion, acidosis, hypothermia and hypocalcaemia rather than a primary cause.
Order of reasoning: haemorrhage first, tension pneumothorax second, tamponade third, myocardial cause last.
Blunt cardiac injury
The right ventricle and the right atrium are immediately retrosternal and therefore the chambers most often injured by anteroposterior compression.
Injury | Findings | Notes |
Myocardial contusion | Regional wall motion abnormality — most often RV free wall or anterior segments — not conforming to a coronary territory | Troponin and ECG drive screening; echocardiography is indicated for haemodynamic instability, arrhythmia, or abnormal ECG/troponin |
Free wall rupture | Haemopericardium, tamponade, PEA arrest | Right-sided chambers most often; frequently fatal at scene |
Valvular disruption | Acute severe regurgitation with a normal-sized chamber; tricuspid most commonly injured, then aortic, then mitral (papillary muscle or chordal rupture) | Acute severity criteria apply (Chapter 17) |
Ventricular septal rupture | Left-to-right shunt on colour Doppler; Qp/Qs | Rare |
Commotio cordis | Ventricular fibrillation from precordial impact during the vulnerable repolarisation window; structurally normal heart | Echocardiography is normal — its role is exclusion of structural injury |
Coronary artery dissection or thrombosis | Regional wall motion abnormality in a coronary distribution | Rare; consider with ECG changes |
Pericardial laceration with cardiac herniation | Grossly displaced heart, obstructive physiology | Rare, immediately life-threatening |
Blunt cardiac injury is a screening diagnosis (ECG plus troponin); echocardiography is indicated when those are abnormal or when the patient is unstable, not as a universal screen.
Traumatic aortic injury
Deceleration injury tears the aorta preferentially at the isthmus, just distal to the left subclavian artery, where the relatively mobile arch meets the ligamentum arteriosum-tethered descending aorta.
Modality | Role |
CT angiography | The reference standard; do it if the patient can travel |
TEE | Excellent for the isthmus and descending aorta; useful in the patient too unstable for CT, and available in the operating theatre. Note the distal ascending aorta / proximal arch blind spot from tracheal air (Chapter 16) |
TTE | Inadequate for exclusion; may show a widened root, AR, or an effusion |
TEE findings: intimal flap, intramural haematoma, pseudoaneurysm, mediastinal haematoma, and periaortic fluid. Distinguish a true flap from reverberation artefact — an artefact moves with the aortic wall, has no independent motion, and does not interrupt colour flow.
Resuscitation-phase echocardiography
Echocardiography contributes at three points in the trauma trajectory.
Phase | Question | Use |
Primary survey | Is there tamponade, pneumothorax, or free fluid? | eFAST |
During massive transfusion | Is the patient responding? Is the RV failing? | Serial LVOT VTI; RV size — transfusion-associated RV dysfunction from volume, acidosis, hypothermia and citrate-induced hypocalcaemia is common and reversible |
Post damage-control | Why is the patient still shocked? | Full haemodynamic assessment; abdominal compartment syndrome, ongoing bleeding, myocardial dysfunction, or vasoplegia |
Ionised hypocalcaemia during massive transfusion is a genuinely reversible cause of myocardial depression and vasoplegia, and it is the first thing to check when a transfused patient develops unexplained cardiac dysfunction.
ICU-Specific Limitations
Confounder | Effect | Response |
Subcutaneous emphysema, chest drains, dressings | Destroys transthoracic windows | Subcostal; TEE |
Cervical spine precautions | Cannot position laterally | Subcostal; laryngoscope-assisted TEE with in-line stabilisation |
Rapidly changing volume state | Findings are valid for minutes | Repeat frequently; document the transfusion state |
Hypothermia and acidosis | Depress contractility independently | Correct before attributing dysfunction to injury |
Positive-pressure ventilation | Alters all preload indices | Interpret with Chapter 12 caveats |
Pelvic fracture, raised intra-abdominal pressure | Passive leg raise invalid or contraindicated | Use other tests |
🛑 Critical pitfall: Excluding cardiac injury on a "normal" pericardial window in penetrating precordial trauma with a large haemothorax. The pericardium may be decompressing into the chest.
🛑 Critical pitfall: Attributing hypotension in a trauma patient to myocardial dysfunction. Haemorrhage is the default diagnosis until controlled; cardiac dysfunction is usually secondary.
🛑 Critical pitfall: Treating a negative eFAST as an exclusion of intra-abdominal haemorrhage in an unstable patient. It detects free fluid, and retroperitoneal bleeding is invisible to it.
- 💡 Clinical pearl: In trauma, judge tamponade by physiology, not volume. A 120 mL acute haemopericardium can be lethal while looking small.
- 💡 Clinical pearl: Check ionised calcium in any transfused patient with new myocardial depression. Citrate-induced hypocalcaemia is common, under-recognised, and immediately correctable.
- 💡 Clinical pearl: Repeat the eFAST. A single early negative scan in an evolving injury is a snapshot; serial scanning converts it into a trend.
References
- American College of Surgeons. Advanced Trauma Life Support, 10th edition — eFAST protocol.
- Isenberg DL, et al. Focused cardiac ultrasound in trauma: ACEP/ASE policy statements.
- Isselbacher EM, Preventza O, Hamilton Black J, et al. 2022 ACC/AHA guideline for the diagnosis and management of aortic disease. Circulation 2022;146:e334–482.
- Clancy K, Velopulos C, Bilaniuk JW, et al. Screening for blunt cardiac injury: an Eastern Association for the Surgery of Trauma practice management guideline. J Trauma Acute Care Surg 2012;73:S301–6.
- Klein AL, Abbara S, Agler DA, et al. ASE recommendations for multimodality imaging of pericardial disease. J Am Soc Echocardiogr 2013;26:965–1012.