Injuries of the Thoracic Organs

1. Classification

By Mechanism

By Anatomical Structure

• Chest wall injuries: Rib fractures, sternal fractures, flail chest
• Pleural space injuries: Pneumothorax (simple, tension, open, occult), hemothorax, hemopneumothorax
• Pulmonary injuries: Pulmonary contusion, laceration, traumatic pneumatocele
• Tracheobronchial injuries: Tracheal or bronchial disruption
• Cardiac injuries: Blunt cardiac injury (myocardial contusion), penetrating cardiac injury, cardiac tamponade
• Great vessel injuries: Blunt thoracic aortic injury (BTAI), subclavian vessel injury
• Esophageal injuries: Penetrating esophageal trauma
• Diaphragmatic injuries: Rupture from blunt or penetrating forces

2. Methods of Examination

Primary Survey (ATLS Framework)

• Airway, Breathing, Circulation assessed immediately
• e-FAST (Extended Focused Assessment with Sonography in Trauma): rapid bedside ultrasound to detect hemothorax, pneumothorax, and pericardial tamponade; superior sensitivity for pneumothorax compared to plain chest radiograph

Imaging

• First-line; upright full-inspiratory film preferred
• Pneumothorax: peripheral lucency beyond lung markings
• Hemothorax: dependent opacification, blunting of costophrenic angle; ~200 mL required for detection on upright CXR, but as little as 5 mL detectable on decubitus film
• An air-fluid level indicates hemopneumothorax
• Detects only ~30% of rib fractures

• Highly sensitive for rib fractures, flail segments, occult pneumothorax, pulmonary contusion, aortic injury
• Occult pneumothorax: visible on CT but absent on CXR — diagnosed more frequently with increased CT use
• Contusion appears as higher-density tissue due to air-space hemorrhage and edema; typically worsens at 24–48 hours
• Differentiation tip: atelectasis does not cross pulmonary fissures; contusion does

• Detects pneumothorax, hemothorax, pericardial effusion within the first minutes of arrival
• Loss of "lung sliding" sign = pneumothorax
• Critical in unstable polytrauma patients

• Gold standard for evaluation of great vessel and aortic injury
• Standard catheter-based angiography (DSA) used if artifact-producing foreign bodies are present

• Bronchoscopy: evaluates trachea and proximal airways for injury
• Esophagoscopy + contrast esophagography: sensitivity approaches 100% when both are combined

• For suspected blunt cardiac injury and pericardial tamponade
• Transesophageal echocardiography useful for thoracic aortic dissection

3. Clinical Presentation & Diagnosis of Specific Injuries

Rib Fractures

• Most common thoracic injury
• Ribs 4–9 most commonly fractured (structurally weakest at the posterior angle)
• Ribs 1–3: protected — fracture indicates severe force
• Ribs 9–11: associated with intra-abdominal injury (hepatic on right, splenic on left)
• Clinical findings: point tenderness, bony crepitus, ecchymosis, muscle spasm; barrel compression test (bimanual compression remote from injury site) reproduces pain at fracture site
• Risk stratification: 2+ rib fractures → higher incidence of internal injury; elderly patients (>65) with multiple rib fractures → higher pneumonia rates and mortality

Flail Chest

• Defined as ≥3 adjacent ribs fractured at ≥2 points, creating a free segment
• Also occurs with costochondral separation or vertical sternal fracture + rib fractures
• Paradoxical motion: flail segment moves inward on inspiration, outward on expiration
• Paradoxical motion is obscured by positive-pressure ventilation
• Underlying pulmonary contusion is the major driver of respiratory insufficiency — not the mechanical instability alone
• Associated injuries: hemopneumothorax, liver/spleen lacerations, mediastinal injury

Fracture of several adjacent ribs in two places with lateral or central flail segments — Rosen's Emergency Medicine

Pneumothorax

• Clinical suspicion of tension PTX = immediate tube thoracostomy — do not delay for imaging
• Asymptomatic occult PTX (CT radial diameter ≤35 mm, no respiratory compromise) → observation + repeat CXR in 12–24 hours

Tension pneumothorax with resolution after left-sided tube thoracostomy — Rosen's Emergency Medicine

Hemothorax

• CXR-visible hemothorax ≈ 400–500 mL → tube thoracostomy recommended
• Retained hemothorax increases morbidity (empyema, fibrothorax risk)
• Massive hemothorax: typically >1,500 mL initial output → thoracotomy consideration

Pulmonary Contusion

• Present in up to 75% of significant blunt chest trauma patients (most commonly MVCs with rapid deceleration)
• Also caused by high-velocity missiles and blast shock waves
• Pathophysiology: alveolar edema and hemorrhage without laceration → physiologic shunt → hypoxemia
• Clinical features: dyspnea, tachypnea, cyanosis, tachycardia, hypotension, chest wall bruising, hemoptysis, moist rales; may be absent on initial CXR but worsens at 24–48 hours
• Young patients (more elastic chest wall) may have severe contusions without rib fractures
• Complications: ARDS, pneumonia, respiratory failure

Left pulmonary contusion on CT — higher-density tissue from air-space hemorrhage — Sabiston Textbook of Surgery

Cardiac Injuries

• Occurs in <1% of penetrating trauma overall; ~10% of penetrating chest trauma

• 90% of penetrating cardiac injuries are immediately lethal pre-hospital

• "Cardiac box": bounded by sternal notch (superior), costal margin (inferior), nipples bilaterally — high-risk zone
• Injury to right ventricle (most anterior structure) is most common
• Beck's Triad (tamponade): hypotension + muffled heart sounds + jugular venous distension

• Wide spectrum: asymptomatic ECG changes → free wall rupture
• Screen with ECG; echocardiography for structural assessment

Blunt Thoracic Aortic Injury (BTAI)

• One of the most common and deadly injuries in trauma patients
• Most commonly from high-speed deceleration
• Invasive aortography has been replaced by MDCTA, transesophageal echocardiography, and MRI
• CT is preferred in emergency settings due to speed and availability

Tracheobronchial Injuries

• Usually result from blunt deceleration or penetrating neck/chest trauma
• Suspect with massive air leak, persistent pneumothorax after tube thoracostomy, subcutaneous emphysema
• Diagnosed with bronchoscopy

Diaphragmatic Injuries

• Can occur from blunt or penetrating mechanisms
• Left side more commonly diagnosed (liver masks right-sided injuries)
• May present acutely with respiratory compromise or delayed with visceral herniation

4. Modern Treatment Methods

Chest Tube (Tube Thoracostomy)

• Bordered by: nipple/inframammary fold (inferior), midaxillary line (posterior), lateral edge of pectoralis major (medial)
• Insertion at 4th–5th intercostal space, just above the rib (avoid neurovascular bundle inferiorly)
• Traditional size: 32–36 Fr; current evidence supports 14-Fr percutaneous catheters with equivalent success and lower morbidity for hemothorax drainage
• Connected to ~20 cmH₂O suction

• All pneumothoraces and hemothoraces visible on CXR
• Tension pneumothorax (clinical suspicion alone is sufficient)
• Hemodynamic instability with suspected pleural injury

Rib Fracture Management

• Single fracture, no complications: outpatient management with analgesia
• Multiple rib fractures / flail chest: multimodal analgesia (NSAIDS, opioids, nerve blocks — including epidural, paravertebral, or serratus anterior plane blocks), pulmonary hygiene, respiratory physiotherapy
• Surgical rib fixation (SSRF): indicated for flail chest with respiratory failure, displaced fractures with severe pain, chest wall deformity

Pulmonary Contusion Management

• Supportive: pulmonary hygiene, multimodal pain control, fluid restriction
• Monitor for respiratory decompensation: hypoxemia, increased work of breathing, agitation
• Mechanical ventilation (lung-protective strategy — low tidal volumes, permissive hypercapnia)
• ECMO for refractory respiratory failure; ELSO registry data shows 61% survival-to-discharge in trauma patients requiring ECMO cannulation
• Murray Lung Injury Score quantifies severity in mechanically ventilated patients and helps predict ECMO need

Indications for Emergency Thoracotomy

• 1,500 mL blood on initial chest tube insertion

• 200 mL/h drainage for ≥4 consecutive hours
• Persistent hemodynamic instability with ongoing transfusion requirement
• Massive air leak with persistent pneumothorax
• Drainage of esophageal or gastric contents from the chest tube (Note: these are traditional Vietnam War-era thresholds; clinical context and resuscitation response guide the decision more than absolute volumes)

Surgical Approaches for Thoracotomy

Penetrating Cardiac Injury

• Immediate pericardiocentesis or pericardial window for tamponade
• Operative repair of cardiac laceration

Damage Control Surgery in the Chest

• Thoracic packing with laparotomy sponges + temporary closure over chest tubes
• Unlike abdominal packing: chest packs must occupy minimal space to allow maximal lung expansion

5. Advanced Technologies in Thoracic Trauma

VATS (Video-Assisted Thoracoscopic Surgery)

• Increasingly used for retained hemothorax, empyema drainage, diaphragm repair, persistent air leaks
• Recent trials show: thoracic cavity irrigation immediately after tube insertion reduces retained hemothorax incidence and reduces need for VATS interventions
• Less morbidity than open thoracotomy

Endovascular / Interventional Radiology

• Endovascular stenting for BTAI: has largely replaced open aortic repair — significantly lower morbidity
• Embolization: for hemorrhage from pulmonary vasculature or intercostal vessels; less morbid alternative to surgery

ECMO (Extracorporeal Membrane Oxygenation)

• Used for refractory hypoxemia from severe pulmonary contusion / ARDS
• Allows lung-protective ventilation while maintaining oxygenation
• ELSO registry: 61% survival in trauma patients

Percutaneous/Minimally Invasive Techniques

• 14-Fr percutaneous chest catheters = equivalent efficacy to large-bore tubes for hemothorax drainage with reduced morbidity
• Ultrasound-guided insertion improves accuracy

Point-of-Care Ultrasound (POCUS / e-FAST)

• Detects pneumothorax, hemothorax, tamponade within minutes
• Integrated into the primary trauma survey
• Superior sensitivity for pneumothorax versus plain CXR
• Guides procedures in real-time (chest tube insertion, pericardiocentesis)

Surgical Lung-Sparing Techniques

• Stapled tractotomy: exposes injured vessels and bronchi for ligation without major resection
• Wedge resection: for peripheral lung injuries
• Lobectomy/pneumonectomy: reserved for massive destruction; trauma pneumonectomy carries >50% mortality

Summary of Key Decision Points