Why is BiPAP (Bilevel Positive Airway Pressure) contraindicated in pneumothorax?

Why BiPAP is Contraindicated in Pneumothorax

BiPAP should be withheld from patients with pneumothorax as long as the pneumothorax is present due to the risk of pneumothorax progression and worsening of the complication. 1

Mechanism of Risk

BiPAP (Bilevel Positive Airway Pressure) delivers positive pressure during both inspiration and expiration, which can have detrimental effects in pneumothorax:

• The positive pressure can force more air into the pleural space through the existing air leak
• This increased air accumulation can:
  • Enlarge the pneumothorax
  • Convert a small pneumothorax to a tension pneumothorax
  • Delay healing of the pleural breach
  • Potentially cause hemodynamic compromise

Evidence-Based Recommendations

The American Journal of Respiratory and Critical Care Medicine guidelines specifically address this issue:

• BiPAP should be withheld from patients with pneumothorax regardless of its size 1
• This recommendation applies for the entire duration that the pneumothorax is present 1
• The panel of experts reached consensus that withholding BiPAP is acceptable management in many circumstances 1

Clinical Management Algorithm

1. Confirm pneumothorax diagnosis

   • Radiographic confirmation (chest X-ray, CT scan)
   • Clinical assessment (decreased breath sounds, hyperresonance)

2. Discontinue BiPAP immediately if pneumothorax is detected

   • Even small pneumothoraces warrant BiPAP discontinuation
   • This applies regardless of the patient's underlying condition

3. Alternative management options:

   • Consider ICU observation for patients who require respiratory support 1
   • Conventional oxygen therapy via nasal cannula or non-rebreather mask
   • Treat the pneumothorax appropriately (chest tube drainage)
   • Consider intubation if respiratory status deteriorates

4. Resumption of BiPAP:

   • Only after complete resolution of pneumothorax
   • Radiographic confirmation of resolution is necessary
   • Consider gradual reintroduction with lower pressures

Special Considerations and Caveats

• Patients with severe underlying respiratory disease:

  • These patients often depend on BiPAP support
  • The panel acknowledged that withholding BiPAP may be problematic for these patients 1
  • Close monitoring in an ICU setting is recommended when BiPAP must be withheld 1

• Case reports of complications:

  • There are documented cases of pneumothorax developing after PAP therapy in patients with underlying lung disease 2
  • A 72-year-old patient with COPD developed pneumothorax after 4 months of APAP use, even at relatively low pressures (4-8 cm H₂O) 2

• Post-pneumothorax precautions:

  • After pneumothorax resolution, patients should avoid:
    • Air travel for at least 2 weeks 1
    • Heavy lifting (>5 pounds) for 2 weeks 1
    • Spirometry for 2 weeks 1

Conclusion

The contraindication of BiPAP in pneumothorax is based on the physiological principle that positive pressure ventilation can worsen air leaks and expand existing pneumothoraces. This recommendation is supported by expert consensus and case reports of complications. While discontinuing BiPAP may present challenges in patients dependent on respiratory support, the risks of continuing BiPAP outweigh the benefits in the presence of pneumothorax.