Pneumothorax

Pneumothoraces are pathological collections of air in the pleural space that result in collapse of the lung and associated respiratory or haemodynamic sequelae. Pneumothoraces are divided into:

Simple pneumothorax
Open pneumothorax
Free communication between the pleura and the atmosphere such that \(P_{pleura} = P_{atm}\).
Tension pneumothorax
Progressive accumulation of gas in the pleural space resulting in ↑↑ \(P_{pleura}\).
- Results in:
  - Lung collapse and hypoxia
  - Mediastinal shift and obstructive shock
- Significantly worse with positive pressure ventilation, which may precipitate cardiac arrest due to the rapid ↑ in \(P_{pleura}\)

In negatively-pressure ventilating patients with a tension pneumothorax, \(P_{pleura}\) is limited by their inspiratory effort (which can still be substantial).

Epidemiology and Risk Factors

Pathophysiology

Open pneumothorax:

Physiological effect depends on the size of the communication

Tension pneumothorax:

Functional one-way valve between the pleural and atmospheric spaces
During inspiration, \(P_{pleura} < P_{atm}\), resulting in entry of gas into the pleural space
During expiration the valve closes, and there is no flow of gas out of the pleural space despite \(P_{pleura} > P_{atm}\)
This results in a progressive ↑ in pleural pressure

Aetiology

Clinical Manifestations

Diagnostic Approach and DDx

Investigations

Bedside:

Laboratory:

Imaging:

Other:

Management

Resuscitation:

Specific therapy:

Pharmacological
Procedural
- Intercostal catheter
  - Single bottle drainage without suction usually adequate
  - Low-pressure suction (-20cmH₂O) should be applied if:
    - Pneumothorax fails to resolve
    - There is associated haemothorax
Physical

Supportive care:

Disposition:

Preventative:

Marginal and Ineffective Therapies

Anaesthetic Considerations

Complications

Prognosis

Key Studies

References

Bersten, A. D., & Handy, J. M. (2018). Oh’s Intensive Care Manual. Elsevier Gezondheidszorg.