From the Guidelines
CPAP therapy should not be used in patients with a tension pneumothorax as it can worsen the condition and potentially lead to life-threatening complications. A tension pneumothorax is a medical emergency where air enters the pleural space but cannot escape, creating pressure that collapses the lung and can shift mediastinal structures. CPAP delivers positive pressure to the airways, which in the presence of a tension pneumothorax would force more air into the pleural space through the existing leak, increasing the pressure and worsening the pneumothorax, as noted in the guidelines for the management of spontaneous pneumothorax 1.
The appropriate management for tension pneumothorax is immediate needle decompression followed by chest tube placement to evacuate the air and allow the lung to re-expand. Only after complete resolution of the pneumothorax and confirmation by imaging should positive pressure ventilation like CPAP be considered, and even then with caution and close monitoring. The physiological reason for this contraindication is that the positive pressure from CPAP would follow the path of least resistance, which in this case would be through the tear in the pleura, exacerbating air accumulation in the pleural space rather than ventilating the lungs.
Some key points to consider in the management of pneumothorax include:
- The development of tension pneumothorax is not dependent on the size of the pneumothorax and the clinical scenario of tension pneumothorax may correlate poorly with chest radiographic findings 1.
- The use of high flow oxygen therapy has been shown to result in a four-fold increase in the rate of pneumothorax reabsorption during periods of oxygen supplementation 1.
- BiPAP should be withheld from patients with pneumothorax as long as the pneumothorax is present, according to the cystic fibrosis pulmonary guidelines 1.
In summary, the use of CPAP in patients with a tension pneumothorax is contraindicated due to the risk of worsening the condition and potentially leading to life-threatening complications. The most recent and highest quality study supporting this recommendation is the cystic fibrosis pulmonary guidelines published in 2010 1.
From the Research
Tension Pneumothorax and CPAP
- There is no direct evidence in the provided studies to suggest that CPAP worsens a tension pneumothorax 2, 3, 4, 5, 6.
- The studies primarily focus on the effectiveness of needle thoracostomy in decompressing tension pneumothorax, with varying degrees of success depending on the catheter length and patient's chest wall thickness 2, 3, 5, 6.
- One study suggests that routine tube thoracostomy may not be necessary after prehospital needle decompression for tension pneumothorax, but rather should be based on clinical indications and imaging results 4.
- The effectiveness of needle thoracostomy is influenced by factors such as catheter length, chest wall thickness, and patient demographics 3, 5, 6.
- The use of CPAP is not mentioned in the context of tension pneumothorax management in the provided studies.
Needle Thoracostomy Efficacy
- The efficacy of needle thoracostomy in decompressing tension pneumothorax varies, with failure rates ranging from 4% to 65% depending on the catheter length and patient population 2, 3, 5.
- Studies suggest that a longer catheter length may be necessary to ensure effective decompression, particularly in patients with thicker chest walls 2, 3, 6.
- The choice of catheter length and needle size should be based on individual patient factors, such as age, gender, and chest wall thickness 6.