🚨 Pulmonary Emergencies A Rapid Reference for Medical Students · High‑Stakes Management
1. Tension Pneumothorax
Definition: One‑way valve mechanism → progressive air accumulation in pleural space → ↑ intrathoracic pressure → impaired venous return → obstructive shock.
Clinical Recognition
- Hypotension, tachycardia, respiratory distress
- Tracheal deviation away from affected side
- Absent breath sounds, hyperresonance to percussion
- Jugular venous distension (unless hypovolemic)
Immediate Management
- Do not wait for CXR. Clinical diagnosis is sufficient.
- Needle Decompression: 14‑16 gauge angiocatheter, 2nd intercostal space, midclavicular line (or 5th ICS anterior axillary line). Insert just above the rib.
- Gush of air confirms diagnosis. Leave catheter in place.
- Tube Thoracostomy (Chest Tube): Place immediately after needle decompression (usually 5th ICS, anterior axillary line).
⚠️ Needle decompression is a temporizing measure. Definitive management is chest tube. If no rush of air with needle, consider other causes of shock/arrest.
2. Massive Hemoptysis
Definition: Expectoration of >300–600 mL blood in 24 hours, or any amount causing hemodynamic compromise or gas exchange abnormality.
Most common source: Bronchial arteries (90%), not pulmonary arteries.
Etiologies
- TB, bronchiectasis, lung cancer, aspergilloma, pulmonary embolism, coagulopathy
Management Algorithm
- Airway Protection: Place patient in lateral decubitus position, bleeding side down to protect contralateral lung.
- Intubate with large ETT (≥8.0) if unable to protect airway or severe hypoxemia. Consider mainstem intubation of unaffected lung.
- Reverse Coagulopathy: FFP, platelets, vitamin K, TXA (inhaled or IV).
- Localization: CXR, then CT angiography (bronchial artery mapping).
- Definitive Control: Bronchial Artery Embolization (BAE) — first‑line interventional therapy. Bronchoscopy may be used for localization/tamponade but BAE is more definitive.
- Surgery (lobectomy/pneumonectomy) reserved for failed BAE or specific lesions (e.g., Rasmussen aneurysm).
💡 "Bleed Down" — Position patient with bleeding lung dependent to prevent aspiration into healthy lung.
3. Acute Upper Airway Obstruction
Causes & Presentation
- Foreign body aspiration: Sudden onset, choking, stridor. Incomplete obstruction: "café coronary" in elderly.
- Angioedema: ACE inhibitor‑related, allergic reaction. Lip/tongue swelling, stridor.
- Epiglottitis: Sore throat, drooling, "tripod" position. Do NOT examine oropharynx or lay patient flat.
- Anaphylaxis: Stridor, wheezing, urticaria, hypotension.
- Post‑extubation stridor: Laryngeal edema.
Immediate Interventions
| Intervention | Indication | Notes |
|---|
| Heliox (70% Helium / 30% O₂) | Temporizing measure for partial obstruction | Lower density gas reduces turbulent flow; requires FiO₂ ≤0.4 to maintain helium fraction |
| Racemic Epinephrine (nebulized) | Post‑extubation stridor, croup | α‑adrenergic vasoconstriction reduces mucosal edema |
| IM Epinephrine | Anaphylaxis / angioedema | 0.3‑0.5 mg IM (lateral thigh) |
| Awake Fiberoptic Intubation | Anticipated difficult airway | Preserves spontaneous ventilation; requires expertise |
| Cricothyroidotomy | "Can't intubate, can't ventilate" | Surgical airway of last resort |
🚫 Avoid sedation/paralysis in upper airway obstruction — loss of airway tone can convert partial to complete obstruction.
4. Status Asthmaticus (Severe Asthma Exacerbation)
Definition: Severe asthma attack unresponsive to initial bronchodilator therapy; risk of respiratory failure.
Signs of Impending Respiratory Arrest
- Altered mental status, exhaustion
- Silent chest (no wheezing — airflow too low to generate sound)
- Paradoxical thoracoabdominal movement
- Normal or elevated PaCO₂ (should be low due to hyperventilation; "normal" PaCO₂ is a warning sign)
- Pulsus paradoxus >25 mmHg
Management Algorithm
- Oxygen: Target SpO₂ 94‑98% (do not restrict O₂ for fear of CO₂ retention — not a concern in acute asthma).
- Continuous Nebulized Bronchodilators: Albuterol + Ipratropium.
- Systemic Corticosteroids: Methylprednisolone 60‑125 mg IV or Prednisone PO. Give early; takes hours to work.
- Magnesium Sulfate: 2 g IV over 20 min. Smooth muscle relaxant. Monitor for hypotension.
- Consider NIPPV (BiPAP): May reduce work of breathing and avoid intubation. Use caution — risk of gastric insufflation.
- Intubation & Mechanical Ventilation (if indicated):
- Use largest ETT possible to reduce resistance.
- Permissive Hypercapnia: Low Vᴛ (6‑8 mL/kg), low RR (8‑12), long expiratory time (I:E 1:4 or 1:5) to prevent auto‑PEEP.
- Ketamine is ideal induction agent (bronchodilator properties).
- Rescue Therapies: Heliox, IV Terbutaline, Inhaled anesthetics (ICU), ECMO.
5. Massive Pulmonary Embolism (PE)
Definition: Acute PE with sustained hypotension (SBP <90 mmHg for >15 min) or requiring vasopressors, or cardiac arrest.
Recognition
- Sudden dyspnea, chest pain, syncope
- Hypotension, tachycardia, ↑ JVP
- ECG: S1Q3T3, RBBB, RV strain
- POCUS: RV dilation, McConnell's sign (RV free wall akinesis with apical sparing), D‑shaped septum
Management Algorithm (ESC Guidelines)
- Anticoagulation: Heparin bolus (80 units/kg) + infusion unless cardiac arrest or extreme hemodynamic instability (then go directly to lytics).
- Assess for Thrombolytics:
- Indicated: Massive PE with hypotension or cardiac arrest.
- Consider in submassive PE: RV dysfunction + elevated troponin + signs of deterioration (no hypotension).
- Contraindications: Recent surgery, bleeding diathesis, prior hemorrhagic stroke.
- Thrombolytic Regimen: tPA (Alteplase) 100 mg IV over 2 hours (or accelerated 0.6 mg/kg over 15 min in cardiac arrest).
- If Thrombolytics Contraindicated or Failed:
- Surgical Embolectomy
- Catheter‑Directed Thrombolysis or Thrombectomy
- Cardiac Arrest: Continue CPR for at least 60‑90 min after lytics (thrombolysis takes time to work). Consider ECMO (ECPR).
💡 In cardiac arrest with suspected PE: Administer thrombolytics immediately (if no absolute contraindications) — this is one of the few reversible causes of PEA arrest.
6. Acute COPD Exacerbation with Hypercapnic Failure
Key ABG Findings
- pH <7.35, PaCO₂ >45, HCO₃⁻ elevated (acute‑on‑chronic)
- Severe acidosis (pH <7.25) indicates need for ventilatory support
Management
- Controlled Oxygen: Target SpO₂ 88‑92%. Start with Venturi mask 24‑28%.
- Bronchodilators: Nebulized SABA + SAMA (albuterol + ipratropium).
- Corticosteroids: Prednisone 40 mg daily or Methylprednisolone IV.
- Antibiotics: If increased sputum purulence or infiltrate.
- Non‑Invasive Ventilation (NIV / BiPAP): First‑line for acute hypercapnic respiratory failure (pH <7.35). Reduces need for intubation and mortality.
- Start IPAP 10‑12, EPAP 4‑5 cm H₂O.
- Titrate IPAP to improve pH/PaCO₂, EPAP to improve oxygenation.
- Intubation if: NIV failure, altered mental status, hemodynamic instability, severe acidosis (pH <7.15) despite NIV.
7. Rapid Deterioration in Mechanically Ventilated Patient (DOPES Mnemonic)
| Letter | Cause | Immediate Action |
|---|
| D | Displacement of ETT | Check depth, listen for breath sounds, EtCO₂ |
| O | Obstruction of ETT (mucus plug, kink, biting) | Suction, pass suction catheter, bite block |
| P | Pneumothorax (tension) | Needle decompression if suspected |
| E | Equipment failure (ventilator, circuit leak) | Disconnect from vent, bag with 100% O₂ |
| S | Stacked breaths (Auto‑PEEP) | Disconnect circuit briefly to allow exhalation, then adjust settings |
8. Other Urgent Pulmonary Scenarios
Inhalational Injury / Smoke Inhalation
- Consider cyanide toxicity (elevated lactate, normal PaO₂). Treat with hydroxocobalamin (Cyanokit).
- Carboxyhemoglobin levels; treat CO poisoning with 100% O₂ or hyperbaric O₂.
- Early intubation for airway edema.
Tracheobronchial Injury
- Blunt trauma → tear at carina or proximal bronchi.
- Signs: subcutaneous emphysema, pneumomediastinum, persistent air leak despite chest tube.
- Bronchoscopy for diagnosis; surgical repair.
Acute Chest Syndrome (Sickle Cell)
- New infiltrate + fever + respiratory symptoms in sickle cell patient.
- Treat with O₂, hydration, pain control, antibiotics (cephalosporin + macrolide), transfusion (simple or exchange).
Severe Pulmonary Hypertension Crisis
- Acute RV failure. Avoid hypoxemia, acidosis, hypothermia, high PEEP.
- Inhaled nitric oxide or IV prostacyclin (epoprostenol).
- Vasopressors: Vasopressin or Norepinephrine (maintain RV perfusion).
9. Top 10 Pulmonary Emergency Pearls
- Tension pneumothorax is a clinical diagnosis — do not delay for imaging.
- In massive hemoptysis, protect the good lung first (bleeding side down).
- A "normal" PaCO₂ in status asthmaticus is a pre‑arrest sign.
- NIV (BiPAP) reduces mortality in COPD exacerbation with acute hypercapnic failure.
- In cardiac arrest with known or suspected PE, give thrombolytics.
- Always check blood glucose in any patient with altered mental status and respiratory distress (DKA can mimic pneumonia/ARDS).
- Angioedema from ACE inhibitors can occur years after starting the drug.
- When in doubt, bag the patient — DOPES covers most vent emergencies.
- Ketamine is the ideal induction agent for intubating severe asthma.
- If needle decompression yields no air but suspicion remains high, place a chest tube — the needle may be too short.