What adjustments should be made to a non-invasive ventilation (NIV) device for an adult patient with a chronic respiratory condition who is experiencing stomach bloating due to swallowing air while using NIV?

Managing Gastric Air Distension (Aerophagia) in NIV Patients

When a patient complains of air in the stomach while using NIV, the primary intervention is to reduce inspiratory pressure (IPAP) to the lowest effective level while maintaining adequate ventilation, and consider switching from a full-face mask to a nasal mask. 1

Immediate Technical Adjustments

Pressure Optimization

• Lower the inspiratory pressure (IPAP) to the minimum level that still controls symptoms and maintains adequate gas exchange 2, 1
• Gastric distension typically indicates poor patient-ventilator coordination and excessive pressure delivery 2
• Check that pressures haven't been set unnecessarily high—many patients are started on IPAP of 15 and escalated to 20-30, but this may be excessive if causing aerophagia 2

Interface Modification

• Switch from full-face mask to nasal mask after initial stabilization, as full-face masks are associated with increased air swallowing 1
• Ensure the mask is not overtightened, as this impairs proper molding and can worsen patient-ventilator asynchrony 2
• Consider alternating between two different interface types if symptoms persist 2

Ventilator Settings Review

• Optimize ventilator settings before assuming the problem is unsolvable 2
• Check for and minimize mask leak, as excessive leak can worsen aerophagia 2
• Ensure proper triggering—flow triggering provides better patient-ventilator synchrony than pressure triggering, especially in COPD 3
• Verify the expiratory port is functioning adequately to allow proper clearance of exhaled air 2

When Conservative Measures Fail

Nasogastric Tube Insertion

• If severe gastric distension persists despite pressure reduction and interface changes, insert a nasogastric tube for decompression 2
• This is particularly important if the distension is causing significant discomfort or compromising ventilation 2

Rule Out Underlying Pathology

• If aerophagia symptoms are intense, persistent, and cannot be controlled by usual measures, perform endoscopic exploration to rule out silent gastric disease 4
• Case reports have identified previously undiagnosed gastric carcinoma presenting as persistent NIV-related aerophagia 4

Alternative Therapies

• For persistent severe aerophagia despite all conservative measures, consider alternative OSA treatments such as mandibular advancement devices (for mild-moderate OSA) 1
• Weight loss should be recommended for all overweight/obese patients 1
• Do not perform hiatal hernia repair specifically for CPAP/NIV-related aerophagia—this is not recommended 1

Common Pitfalls to Avoid

• Never ignore persistent aerophagia symptoms—they may indicate serious patient-ventilator asynchrony or underlying pathology 2, 4
• Don't continue escalating pressures if aerophagia develops; instead, reassess the entire NIV setup 2
• Avoid using oxygen flow rates >4 L/min as this can cause mask leak and delayed triggering, worsening asynchrony 2
• Don't assume all abdominal distension is benign—persistent symptoms warrant investigation 4

Monitoring Strategy

• Reassess the patient frequently after making adjustments 2
• Monitor for signs of NIV failure: worsening pH, rising respiratory rate, or patient distress 2
• Check arterial blood gases 1-2 hours after making ventilator changes to ensure adequate ventilation is maintained despite lower pressures 2, 5
• Use transcutaneous CO₂ monitoring if available to guide pressure adjustments without repeated blood sampling 2