Systemic air embolization from penetrating lung injury.

Area of Science:

• Cardiovascular Physiology
• Pulmonary Medicine
• Surgical Complications

Background:

• Systemic air embolism is a potential complication during mechanical ventilation and thoracic procedures.
• Understanding the threshold for intratracheal pressure leading to air embolization is critical for patient safety.

Purpose of the Study:

• To investigate the relationship between increased intratracheal pressure and the development of systemic air embolization.
• To determine if lung injury influences the incidence or severity of air embolization.

Main Methods:

• Mongrel dogs were used to model systemic air embolism.
• Air emboli were visualized using an extracorporeal arteriovenous shunt and detected with a Doppler flow probe.
• Intratracheal, intrapleural, and systemic pressures were monitored.
• Groups included controls and dogs with penetrating lung wounds, with variations in chest closure.

Main Results:

• No air embolization was observed below an intratracheal pressure of 65 mm Hg.
• All animals experienced systemic air embolization when intratracheal pressure exceeded 65 mm Hg.
• Penetrating lung wounds resulted in a greater quantity of embolized air compared to controls.

Conclusions:

• Intratracheal pressures exceeding 65 mm Hg are a direct cause of systemic air embolization.
• The presence of a penetrating lung wound exacerbates air embolization quantity under hyperinflation conditions.
• These findings underscore the importance of managing intratracheal pressure to prevent air embolism.