What is the clinical presentation and role of Non-invasive ventilation (NIV) in the management of tracheobronchomalacia in the acute setting?

Clinical Presentation and Role of NIV in Tracheobronchomalacia Management in the Acute Setting

Non-invasive ventilation (NIV) can be used as a management option for tracheobronchomalacia (TBM) in the acute setting, particularly when respiratory acidosis develops, but should be implemented with caution due to the risk of worsening airway collapse. 1, 2

Clinical Presentation of Tracheobronchomalacia

Tracheobronchomalacia presents with characteristic symptoms that result from excessive airway collapse during expiration:

• Expiratory stridor - a hallmark finding due to dynamic airway narrowing during expiration 1
• Barking or "brassy" cough - distinctive sound caused by vibration of the weakened tracheal walls 1, 3
• Recurrent respiratory tract infections - due to poor secretion clearance 1, 2
• Dyspnea - often worsened with exertion or during respiratory infections 2
• Acute life-threatening events - in severe cases, particularly in pediatric patients 1
• Respiratory failure - can develop in advanced cases with significant airway collapse 2

In the acute setting, patients may present with:

• Acute exacerbation of symptoms during respiratory infections 3
• Respiratory distress with increased work of breathing 4
• Hypercapnic respiratory failure with respiratory acidosis 2
• Difficulty clearing secretions, leading to atelectasis and pneumonia 2

Role of NIV in Management

NIV can play a role in the management of TBM in the acute setting, though evidence is limited compared to its use in other respiratory conditions:

Indications for NIV in TBM:

• Hypercapnic respiratory failure - NIV should be considered in patients with TBM who develop respiratory acidosis (pH <7.35) 5
• As a bridge to definitive treatment - NIV may provide temporary support while preparing for more definitive interventions 1
• In patients who are not candidates for invasive ventilation - NIV may be used as a ceiling of treatment 5

Implementation of NIV:

• Ventilator settings:

  • Bi-level pressure support ventilators are recommended for acute NIV service 5
  • Positive end-expiratory pressure (PEEP) helps maintain airway patency during expiration 5
  • Careful titration of pressures is needed to avoid excessive airway collapse 2

• Interface selection:

  • In the acute setting, a full-face mask should be used initially, changing to a nasal mask after 24 hours as the patient improves 5
  • A selection of different sizes should be available to ensure proper fit 5

Monitoring and Assessment:

• Arterial blood gas analysis should be performed after 1-2 hours of NIV and again after 4-6 hours if the earlier sample showed little improvement 5
• Continuous oxygen saturation monitoring for at least 24 hours after commencing NIV 5
• Regular clinical evaluation including assessment of patient comfort, respiratory rate, and coordination with the ventilator 5

Cautions and Considerations

• Risk of worsening collapse - Positive pressure may paradoxically worsen airway collapse in some TBM patients 2
• Secretion management - Copious respiratory secretions may limit NIV effectiveness 5
• Location of care - Patients with severe TBM requiring NIV should be managed in a high-dependency unit or ICU setting 5
• Failure criteria - If there is no improvement in PaCO2 and pH after 4-6 hours despite optimal ventilator settings, NIV should be discontinued and invasive ventilation considered 5

Alternative and Definitive Management Options

• Medical management - Treatment of underlying conditions like COPD, asthma, or gastroesophageal reflux 2
• Continuous positive airway pressure (CPAP) - May be used for less severe cases 4
• Surgical options - For severe cases, surgical approaches such as tracheobronchoplasty, tracheopexy, or aortopexy may be needed 1, 4
• Airway stenting - Can be used to identify patients who might benefit from surgical treatment 2

NIV should be implemented as part of a comprehensive management plan for TBM patients in the acute setting, with clear decisions about escalation of care if NIV fails 5.