An open pneumothorax is a medical emergency caused by a penetrating chest injury. It occurs when an opening in the chest wall allows outside air to directly enter the space surrounding the lung, rapidly impairing breathing and leading to severe complications if not addressed promptly.
Understanding the Condition
The lungs reside within the chest cavity, surrounded by a double-layered membrane called the pleura. The inner layer, the visceral pleura, covers the lung surface, while the outer layer, the parietal pleura, lines the inside of the chest wall. Between these two layers is a narrow, fluid-filled area known as the pleural space. Normally, this space maintains a negative pressure, which helps the lungs remain expanded.
An open pneumothorax, also referred to as a “sucking chest wound,” develops when a defect in the chest wall creates a direct connection between the atmosphere and this pleural space. As air enters the pleural space, the delicate balance of pressure is disrupted, causing the affected lung to partially or completely collapse. The degree of lung collapse directly relates to the size of the opening and the amount of air that enters.
How It Occurs
Open pneumothoraces result from penetrating chest injuries, such as stab wounds, gunshot wounds, or impalement. These injuries create a defect in the chest wall, allowing atmospheric air to bypass the normal airway and directly enter the pleural cavity.
When the opening in the chest wall is large, air preferentially enters through this wound rather than through the windpipe into the lungs during inhalation. This mechanism means that with each breath, more air can accumulate in the pleural space, further compressing the lung.
Identifying the Signs
Signs of an open pneumothorax include a visible chest wound that breaches the skin and chest wall. Difficulty breathing, characterized by shortness of breath and rapid, shallow breaths, occurs as the lung cannot expand fully.
A characteristic “sucking” or bubbling sound may be heard as air moves in and out through the wound with each breath. The affected person might also experience chest pain localized to the injury site. In more severe cases, signs of shock, such as low blood pressure, weakness, and dizziness, can develop due to the compromised lung function affecting the body’s overall oxygen supply.
Immediate Action and Treatment
For an open pneumothorax, immediately call emergency medical services, such as 911. While awaiting professional medical help, temporary first aid can be applied.
A temporary measure involves using an occlusive dressing, like a piece of plastic or non-porous material, to cover the wound. This dressing should be taped securely on three sides, leaving one side untaped. This creates a flutter-valve effect, which allows air trapped in the pleural space to escape during exhalation but prevents additional outside air from entering during inhalation. This helps to reduce further lung collapse.
Once in a medical setting, professional treatment involves inserting a chest tube into the pleural space. This tube removes the accumulated air, allowing the lung to re-expand and heal. Surgical repair of the chest wall defect may be necessary to fully address the injury.