Management of Reduced Diaphragmatic Excursion
For patients with reduced diaphragmatic excursion, initiate non-invasive ventilation (NIV) promptly if there are signs of respiratory distress or hypercapnia, while simultaneously treating the underlying cause and optimizing airway clearance techniques. 1
Initial Assessment and Monitoring
When reduced diaphragmatic excursion is identified, immediately assess for:
- Signs of respiratory distress or hypercapnia requiring urgent intervention 1
- Oxygen saturation targets: Maintain SpO2 88-92% in adults (avoid excessive oxygen that worsens hypercapnia) 1
- CO2 monitoring: Use transcutaneous monitoring or arterial blood gases to track hypercapnia 1
- Underlying etiology: Identify reversible causes (phrenic nerve injury, neuromuscular disease, post-surgical complications) 2, 3
Non-Invasive Ventilation Protocol
NIV should be initiated early in symptomatic patients with diaphragmatic dysfunction showing respiratory compromise 1:
- Bi-level pressure support is the preferred mode for acute hypercapnic respiratory failure 4
- Initial ventilator settings for COPD patients with diaphragmatic dysfunction: Start with appropriate IPAP/EPAP levels and titrate based on blood gas response 4
- Target correction of respiratory acidosis (PaCO2 >45 mmol/L, pH <7.35) within 1-4 hours 4
- Consider controlled ventilation modes as patient triggering may be ineffective with severe diaphragmatic dysfunction 1
NIV Monitoring and Adjustment
- Reassess at 1-2 hours with arterial blood gas analysis 4
- Expected improvement: pH and PaCO2 should show improvement by 1-4 hours; lack of progress indicates NIV failure 4
- If NIV fails after 4-6 hours of optimal settings with no improvement in PaCO2 and pH, proceed to intubation unless invasive ventilation is not desired 4, 1
Airway Clearance Optimization
Aggressive airway clearance is critical in patients with reduced diaphragmatic excursion who have impaired cough:
- Mechanical insufflation-exsufflation is strongly recommended for patients with neuromuscular disease and peak cough flows <270 L/min or maximal expiratory pressures <60 cm H2O 4
- Manually assisted cough techniques should be taught and employed early during respiratory illnesses 4
- Home pulse oximetry is useful to monitor effectiveness of airway clearance and identify patients needing hospitalization 4
Treatment of Underlying Conditions
Optimize medical management based on etiology:
- Ensure maximal medical treatment for underlying conditions (COPD, neuromuscular disease) is prescribed and administered 4
- Consider physiotherapy for sputum retention 4
- Rule out complications: pneumothorax, aspiration pneumonia, bronchospasm 4
Escalation Criteria
Do not delay intubation if NIV fails, particularly in single-organ respiratory failure where recovery prospects are good 1:
- Indications for intubation: Deteriorating conscious level, worsening blood gases despite optimal NIV, inability to protect airway, patient exhaustion 4
- Plan extubation carefully in a specialist center with NIV and mechanical insufflator-exsufflator support available post-extubation 1
- Prophylactic NIV after extubation should be considered for high-risk patients 1
Long-Term Management Considerations
- Continue nocturnal NIV following acute hypercapnic respiratory failure pending specialist home ventilation service consultation 1
- Physiotherapy before and after extubation reduces weaning duration and extubation failure risk 1
- Advance care planning regarding future invasive ventilation should be discussed, particularly in progressive neuromuscular disease 1
Critical Pitfalls to Avoid
- Avoid diaphragmatic pacing in ALS patients with respiratory failure, as it is associated with decreased survival (median 11.0 vs 22.5 months without pacing) 5
- Do not rely on oxygen therapy alone without addressing ventilation; this worsens hypercapnia 1
- Do not delay invasive ventilation when NIV clearly fails after 4-6 hours of optimal therapy 4, 1
- Ensure proper NIV mask fit and minimize leaks to optimize ventilation effectiveness 4