Non-traumatic Thoracic Emergencies

Pulmonary Embolism - Clot Blockade

• Pulmonary artery obstruction by embolus (often DVT).
• Risk Factors: Virchow's Triad 📌 S.H.E. (Stasis, Hypercoagulability, Endothelial injury).
• Clinical: Sudden dyspnea, pleuritic pain, tachypnea, tachycardia.
• Diagnosis:
  • Pre-test probability (Wells/Geneva) + D-dimer.
  • CTPA (Gold Standard): Intraluminal filling defects.
    • Signs: Westermark sign (oligemia), Hampton's hump (infarct), Palla's sign (dilated R descending PA), Fleischner sign (dilated central PA).
    • RV strain signs (RV dilatation, septal bowing).
  • V/Q scan (if CTPA contraindicated).
  • ECG: S1Q3T3 (classic, rare), sinus tachycardia.
• Management: Anticoagulation; Thrombolysis for massive PE.

⭐ Westermark sign: Focal oligemia distal to an occluding embolus, seen on CXR/CT.

Aortic Dissection - Aorta's Agony

• Intimal tear allows blood to enter aortic media, creating a false lumen.
• Key Risks: Hypertension (most common), Marfan syndrome, bicuspid aortic valve.
• Presentation: Sudden, severe "tearing" or "ripping" chest/back pain.
• Classification:
  • Stanford:
    • Type A: Involves ascending aorta.
    • Type B: Descending aorta only (distal to left subclavian artery).
• Imaging:
  • CTA (Chest+Abdomen+Pelvis with contrast): Modality of choice.
    • Identifies intimal flap, true/false lumens, extent, branch vessel involvement, complications (e.g., pericardial effusion).
• Management Flow:

⭐ Stanford Type A dissections are surgical emergencies due to high risk of cardiac tamponade or acute aortic regurgitation.

Pneumothorax - Pressure Peril

• Air in pleural space, leading to lung collapse.
• Types:
  • Spontaneous (primary/secondary), traumatic, iatrogenic.
  • Tension: Medical emergency! ↑Intrapleural pressure → mediastinal shift → ↓venous return.
• Imaging:
  • CXR (PA, expiratory): Visceral pleural line, absent peripheral lung markings.
  • Supine CXR: Deep sulcus sign (tension pneumothorax).
  • CT: Most sensitive; detects small pneumothoraces, bullae/blebs.
• Tension Pneumothorax:
  • Clinical: Hypotension, JVD, tracheal deviation (late), hyperresonant percussion.
  • Immediate needle decompression (2nd ICS MCL or 5th ICS MAL), then chest tube.

⭐ Deep Sulcus Sign: On a supine chest X-ray, this sign indicates a pneumothorax, often a tension pneumothorax. It refers to a deep, lucent costophrenic angle on the affected side due to air accumulation anterolaterally in the pleural space when the patient is supine. Critical for supine trauma/ICU patients where upright films aren't feasible.

📌 Mnemonic for Tension Pneumothorax signs: P-THORAX Pleuritic pain Tracheal deviation Hyperresonance Onset sudden Reduced breath sounds (& dyspnea) Absent fremitus X-ray (mediastinal shift, deep sulcus sign)

Lung & Gullet Crises - Thoracic Threats

• Acute Respiratory Distress Syndrome (ARDS)
  • Pathophysiology: Diffuse alveolar damage (DAD) from sepsis, pneumonia, aspiration.
  • CXR: Bilateral, diffuse, fluffy opacities ("white-out lung"); spares costophrenic angles early.
  • CT: Widespread ground-glass opacities (GGO), consolidation; often dependent distribution.
  • Key: Berlin criteria PaO2/FiO2 < 300 mmHg; opacities not solely cardiac.
• Boerhaave's Syndrome
  • Pathophysiology: Transmural esophageal rupture, usually post-forceful emesis.
  • Common site: Left posterolateral aspect, distal esophagus.
  • CXR: Pneumomediastinum, left pleural effusion, subcutaneous emphysema. Look for Naclerio's V sign.
  • CT: Definitive diagnosis; shows esophageal defect, peri-esophageal air/fluid, extraluminal contrast.

  ⭐ Mackler's Triad (clinical, not radiological): Vomiting, severe retrosternal chest pain, subcutaneous emphysema.

High‑Yield Points - ⚡ Biggest Takeaways

• Pulmonary Embolism: CTPA is gold standard (shows filling defects). Signs: Westermark, Hampton's hump.
• Aortic Dissection: Stanford A (ascending) = surgical emergency. Stanford B (descending) = medical. Intimal flap on CT.
• Tension Pneumothorax: Mediastinal shift is key. Requires urgent needle decompression.
• Acute Pulmonary Edema: Batwing opacities, Kerley B lines, pleural effusions, cardiomegaly.
• Esophageal Rupture (Boerhaave): Pneumomediastinum crucial. Confirm with water-soluble contrast esophagogram.