What is the best management approach for a patient with severe respiratory acidosis, on BiPAP (Bilevel Positive Airway Pressure), and has a DNR (Do Not Resuscitate) status?

Management of Severe Respiratory Acidosis in a DNR Patient on BiPAP

For a patient with severe respiratory acidosis (CO2 144, pH 7.05) who is already on BiPAP and has DNR status, the recommended approach is to optimize BiPAP settings immediately, including increasing inspiratory positive airway pressure (IPAP) to 15-20 cmH2O and setting expiratory positive airway pressure (EPAP) at 4-8 cmH2O, while targeting a respiratory rate of 12-16 breaths/min. 1

Immediate BiPAP Optimization

• Increase IPAP to 15-20 cmH2O to improve ventilation
• Set EPAP at 4-8 cmH2O to maintain airway patency
• Target respiratory rate of 12-16 breaths/min
• Adjust FiO2 to maintain oxygen saturation between 88-92% 1
• Ensure proper mask fit to minimize air leaks

Monitoring and Reassessment

• Repeat arterial blood gas within 60 minutes of adjusting BiPAP settings 1
• Look for improvement in pH, PCO2, and respiratory rate
• If no improvement is seen after 1-2 hours despite optimal ventilator settings, consider the following: 2
  • Further adjustment of BiPAP parameters
  • Evaluation for reversible causes
  • Discussion with patient/family about goals of care given DNR status

Pharmacological Management

• Administer nebulized bronchodilators if bronchospasm is present:
  • β-agonist (salbutamol 2.5-5 mg) and/or
  • Anticholinergic agent (ipratropium bromide 0.25-0.5 mg) every 4-6 hours 1
• Consider systemic corticosteroids if COPD exacerbation is suspected (prednisolone 30 mg daily) 1
• Start appropriate antibiotics if infection is suspected 1

Special Considerations for DNR Patients

• DNR status does not preclude the use of NIV as an active therapeutic intervention 1
• Document clear goals of care and parameters for continuation or withdrawal of NIV
• Ensure the patient and family understand that NIV is being used as active treatment, not just for comfort 1
• Continue NIV for as much time as possible in the first 24 hours if showing benefit 2

Potential Complications to Monitor

• Electrolyte disturbances, particularly hypokalemia, which can occur with rapid correction of respiratory acidosis 3
• Monitor serum potassium levels closely and replace as needed
• Watch for signs of respiratory muscle fatigue
• Monitor for signs of patient discomfort or intolerance of BiPAP

When to Consider Withdrawal of BiPAP

• If there is no improvement in arterial blood gases after 4-6 hours of optimized therapy 2
• If the patient experiences increasing distress or discomfort with BiPAP
• If the goals of care shift toward comfort measures only
• In accordance with the patient's advance directives and DNR status

This approach respects the patient's DNR status while still providing appropriate therapeutic interventions to address the severe respiratory acidosis. The British Thoracic Society guidelines emphasize that NIV can be appropriate for DNR patients as a therapeutic measure, with clear documentation of goals and parameters for continuation or withdrawal 1.