Flail Chest
Definition
Flail chest occurs when three or more adjacent ribs are fractured in two or more places, causing a free-floating segment that moves paradoxically with respiration.
It is considered a clinical diagnosis as everybody with this fracture pattern does not develop a flail chest.
1. Pathophysiology:
• During inspiration, negative intrathoracic pressure pulls the flail segment inward, The motion of the flail segment is paradoxical to the rest of the chest. It is paradoxical because the flail segment moves inward while the rest of the chest wall moves outward,reducing ventilation efficiency.
• During expiration, the segment moves outward, impairing effective expiration.
• Associated pulmonary contusion worsens oxygenation and increases shunting.
• Leads to hypoxia, hypercapnia, and respiratory failure.
2. Clinical Presentation
• Paradoxical chest wall movement (hallmark sign).
• Severe chest pain and respiratory distress.
• Tachypnea, cyanosis, hypoxia.
• Crepitus and tenderness on palpation.
• Associated injuries: Pneumothorax, hemothorax, pulmonary contusion.
3. Diagnosis
A. Clinical Diagnosis:
• Observation of paradoxical movement.
• Chest tenderness and crepitus on palpation.
B. Imaging:
• Chest X-ray (CXR): Multiple rib fractures(not very sensitive and may miss rib fractures), underlying lung injury.
• CT Chest specifically with 3D reconstruction.(Gold Standard): Detects fractures, contusion, pneumothorax, and vascular injury.
• Ultrasound: FAST scan for associated hemothorax.
Emergency Department (ED) Management
1. Initial Resuscitation (ABCDE Approach)
A. Airway:
• Assess for airway obstruction or need for endotracheal intubation.
• Consider early intubation if severe respiratory distress or hypoxia.
B. Breathing:
• High-flow oxygen (100%) via a non-rebreather mask.
• Positive pressure ventilation (PPV) if hypoxia persists.
• Treat associated pneumothorax/hemothorax with chest tube insertion (thoracostomy).
C. Circulation:
• Control hemorrhage if present.
• Fluid resuscitation (Balanced crystalloids) to maintain perfusion.
• Blood transfusion if hemorrhagic shock.
D. Disability (Neurological Status):
• Assess GCS and spinal cord injury.
E. Exposure:
• Look for associated injuries (head, spine, abdomen, extremities).
2. Pain Management (Essential for Recovery)
• IV Opioids (Fentanyl/Morphine): Preferred for severe pain.
• Regional anesthesia (Epidural or Paravertebral Block):
• Epidural analgesia (Thoracic, T4-T8): Best for improving ventilation.
• Paravertebral block: Alternative to epidural.
• Intercostal nerve blocks for localized pain relief.
• Avoid excessive sedation to prevent respiratory depression.
3. Respiratory Support
A. Non-Invasive Ventilation (NIV) (First-Line in Mild-Moderate Cases)
• BiPAP or CPAP improves oxygenation and stabilizes the flail segment.
• Used in patients without severe pulmonary contusion.
B. Mechanical Ventilation (Indications for Intubation)
• Severe respiratory distress/hypoxia despite oxygen therapy.
• PaO₂ < 60 mmHg on high-flow oxygen.
• Hypercapnia with respiratory acidosis (pH < 7.25).
• Associated head injury with low GCS (<8).
-Ventilator Strategy:
• Low tidal volume (6 mL/kg PBW) to prevent barotrauma.
• PEEP (5-8 cmH₂O) to prevent atelectasis.
• Permissive hypercapnia to reduce ventilator-induced lung injury.
Anesthesia Considerations in Flail Chest
1. Preoperative Assessment
• Assess oxygenation and ventilation status (ABG, SpO₂, CXR).
• Evaluate associated injuries (head, spine, abdomen).
• Optimize pain control (epidural or nerve blocks).
2. Induction of Anesthesia
• Rapid Sequence Induction (RSI) preferred if full stomach/trauma.
• Ketamine (1-2 mg/kg IV): Preserves respiratory drive and hemodynamics.
• Etomidate (0.3 mg/kg IV): Hemodynamically stable induction.
• Succinylcholine or Rocuronium for paralysis.
3. Maintenance of Anesthesia
• Balanced anesthesia with low-dose volatile agents + opioids.
• Lung-protective ventilation:
• Low tidal volumes (6 mL/kg PBW)
• PEEP to prevent atelectasis
• Avoid excessive PEEP (risk of barotrauma).
4. Extubation Strategy
• Early extubation if pain well-controlled and oxygenation adequate.
• Delay extubation if severe contusion or poor respiratory effort.
ICU Management of Flail Chest
1. Pain Control:
• Epidural analgesia preferred (reduces mechanical ventilation need).
• Opioid PCA or multimodal analgesia (paracetamol, NSAIDs, nerve blocks).
2. Respiratory Support:
• NIV (BiPAP/CPAP) for mild-moderate cases.
• Mechanical ventilation if severe contusion or hypoxia.
3. Ventilator Weaning Criteria:
• PaO₂/FiO₂ > 200
• No excessive secretions.
• Strong cough and adequate tidal volume.
4. Prevention of Complications:
• DVT Prophylaxis: LMWH (Enoxaparin 40 mg SC daily).
• Pulmonary Hygiene: Incentive spirometry, chest physiotherapy.
• Early mobilization to prevent pneumonia.
MCQs (Multiple Choice Questions)
1. Which of the following is the hallmark sign of flail chest?
A) Hemoptysis
B) Crepitus
C) Paradoxical chest movement
D) Hyperresonance on percussion
Answer: C) Paradoxical chest movement
2. What is the preferred pain management method in flail chest?
A) IV Paracetamol
B) Epidural analgesia
C) High-dose opioids
D) Ketamine infusion
Answer: B) Epidural analgesia
3. Which of the following is an absolute indication for intubation in flail chest?
A) Pain score >7/10
B) Mild hypoxia (SpO₂ 92%)
C) Severe respiratory distress with hypoxia
D) Rib fractures only
Answer: C) Severe respiratory distress with hypoxia
Viva Questions and Model Answers
1. Why is epidural analgesia preferred in flail chest?
• Answer: It improves ventilation, prevents pneumonia, and reduces mechanical ventilation need.
2. What ventilatory strategy is preferred in intubated patients with flail chest?
• Answer: Lung-protective ventilation (low tidal volume, moderate PEEP).
3. What is the role of NIV in flail chest management?
• Answer: Supports breathing, stabilizes chest wall, and reduces intubation need.