What are the next steps after Non-Invasive Ventilation (NIV) failure?

Management After Non-Invasive Ventilation (NIV) Failure

If there has been no improvement in PaCO2 and pH after 4-6 hours of NIV despite optimal settings, NIV should be discontinued and invasive mechanical ventilation considered. 1

Defining NIV Failure

NIV failure should be assessed systematically based on multiple clinical and physiological parameters 1:

• Deterioration in patient's condition (worsening vital signs, increased work of breathing) 1
• Failure to improve or deterioration in arterial blood gas tensions after 4-6 hours 1
• Development of new complications such as pneumothorax, aspiration pneumonia, or sputum retention 1
• Intolerance or failure of coordination with the ventilator 1
• Deteriorating conscious level 1
• Patient and carer wish to withdraw treatment 1

Systematic Troubleshooting Before Declaring Failure

Before proceeding to intubation, systematically address potentially reversible causes 1:

Optimize Underlying Disease Treatment

• Verify all prescribed medical treatments have been administered 1
• Consider physiotherapy for sputum retention 1
• Rule out new complications (pneumothorax, aspiration pneumonia) 1

Address Technical Issues if PaCO2 Remains Elevated

Oxygen delivery problems:

• Adjust FiO2 to maintain SpO2 between 85-90% (excessive oxygen can worsen hypercapnia) 1

Interface problems:

• Check mask fit for excessive leakage 1
• If using nasal mask, consider chin strap or full-face mask 1

Circuit problems:

• Verify all connections are correct 1
• Check entire circuit for leaks 1

Re-breathing issues:

• Check patency of expiratory valve 1
• Consider increasing EPAP (if using bi-level pressure support) 1

Patient-ventilator asynchrony:

• Directly observe the patient 1
• Adjust rate and/or inspiratory-expiratory ratio 1
• Check and adjust inspiratory trigger settings 1
• Check and adjust expiratory trigger settings 1
• Consider increasing EPAP in COPD patients on bi-level pressure support 1

Inadequate ventilation:

• Observe chest expansion 1
• Increase target pressure (IPAP) or tidal volume 1
• Consider increasing inspiratory time 1
• Consider increasing respiratory rate to increase minute ventilation 1
• Consider switching to a different ventilation mode or ventilator 1

Address Persistent Hypoxemia (if PaCO2 improves but PaO2 remains low)

• Increase FiO2 1
• Consider increasing EPAP with bi-level pressure support 1

Critical Timing for Arterial Blood Gas Assessment

Measure arterial blood gases after 1-2 hours of NIV, then again after 4-6 hours if the earlier sample showed little improvement. 1 This timing is critical because:

• Early assessment (1-2 hours) identifies rapid responders who will likely succeed 1
• The 4-6 hour timepoint is the decision point for continuing versus abandoning NIV 1
• Delaying intubation beyond this timepoint in non-responders increases mortality risk 2, 3

Decision to Proceed to Invasive Ventilation

A management plan for NIV failure should be established early, ideally by a respiratory physician, and the decision to progress to intubation should be made by an experienced clinician in consultation with ICU staff. 1

Indications for Immediate Intubation (Do Not Attempt NIV)

• Recent facial or upper airway surgery 1
• Facial burns or trauma 1
• Fixed upper airway obstruction 1
• Active vomiting 1
• Inability to protect the airway 1
• Life-threatening hypoxemia 1
• Hemodynamic instability 1
• Coma or severe confusion/agitation 1

Proceed to Intubation After NIV Trial When:

• No improvement in pH and PaCO2 after 4-6 hours despite optimal ventilator settings 1
• Progressive deterioration in clinical condition or arterial blood gases 1
• Development of absolute contraindications during NIV trial 1
• Patient exhaustion or inability to tolerate NIV despite troubleshooting 4

Special Considerations

For patients with severe ARDS (PaO2/FiO2 < 200 mmHg): NIV should only be attempted in hemodynamically stable patients in an ICU setting with highly skilled staff and immediate intubation capability 2. The high failure rate in this population (often >50%) mandates extremely close monitoring and low threshold for intubation 2.

Location of care: Patients with more severe acidosis (pH <7.30) should be managed in a higher dependency area such as HDU or ICU, as should those showing no improvement after 1-2 hours of NIV on a respiratory ward 1.

Common Pitfalls to Avoid

• Delaying intubation in patients with progressive deterioration—this increases mortality 2, 3
• Simply increasing FiO2 without clinical re-evaluation when blood gases fail to improve 1
• Inadequate monitoring frequency in the first 4-6 hours of NIV 1
• Failing to establish a clear management plan before initiating NIV 1
• Attempting NIV in patients with absolute contraindications who require immediate intubation 1