A sucking chest wound, formally termed an open pneumothorax, is a severe injury where penetrating trauma creates a direct opening in the chest wall. This breach allows outside air to enter the chest cavity, immediately interfering with the body’s ability to breathe. Since this injury can quickly lead to respiratory failure, it is a life-threatening condition that requires immediate action.
The Mechanism of a Sucking Chest Wound
Normal respiration relies on the integrity of the chest wall to maintain a specific environment within the thoracic cavity. The pleural space, located between the lung surface and the inner chest wall, naturally maintains negative pressure (slightly lower than the atmosphere). This pressure difference is what keeps the lungs fully expanded and able to inflate with each breath.
A penetrating injury, such as a stab or gunshot wound, compromises this sealed system by creating a pathway to the pleural space. Since outside pressure is higher than the pressure within the chest cavity, air rushes inward through the wound when the injured person inhales. This influx of air equalizes the pressure, eliminating the negative pressure gradient that holds the lung against the chest wall.
The result is a pneumothorax, or collapsed lung, on the injured side. If the opening in the chest wall is about two-thirds the diameter of the trachea or larger, air preferentially enters through the external wound instead of the airway. This mechanism severely reduces oxygen exchange capability and can rapidly lead to respiratory distress.
Recognizing the Signs of Penetrating Chest Trauma
The most distinct indicator of a sucking chest wound is the auditory sign produced by the movement of air. As the injured person breathes, a characteristic “sucking,” “hissing,” or bubbling sound can be heard as air is pulled into or pushed out of the wound. This sound confirms that the chest wall has been breached and is communicating directly with the atmosphere.
Visually, the wound site may show signs of trauma, often accompanied by bleeding. If fluids are present, air escaping during exhalation can cause bubbling or frothing around the wound opening. The injured person will experience shortness of breath and may resort to rapid, shallow breathing to compensate for reduced lung function.
Additional symptoms include sharp, localized chest pain worsened by deep breaths, and signs of poor oxygenation, such as anxiety or confusion. Any penetrating injury to the chest, especially one roughly the size of a coin or larger, should be treated as a sucking chest wound due to the seriousness of the injury.
Immediate First Aid Response
The first and most important step for any bystander is to immediately contact emergency medical services. While waiting for their arrival, the primary goal of first aid is to prevent outside air from entering the chest cavity while allowing trapped air to escape. This is accomplished by applying an occlusive, or airtight, chest seal.
If a commercially made chest seal is unavailable, an improvised occlusive dressing can be created using any clean, non-porous material, such as sterile plastic packaging or a plastic bag. The material should completely cover the wound and overlap the surrounding skin by several inches to ensure a proper seal. This dressing is then secured to the chest wall with tape on three sides only.
This technique creates a flutter-valve effect, which is the most important element of field treatment. When the injured person inhales, negative pressure pulls the dressing against the skin, sealing the wound and preventing air entry. When the person exhales, increased pressure inside the chest pushes air out from underneath the unsecured fourth side. This venting mechanism mitigates the risk of a tension pneumothorax, a severe condition where air builds up and compresses the heart and uninjured lung.
The three-sided seal should be monitored closely. If the injured person’s breathing worsens after application, the seal may need to be momentarily lifted to release excessive pressure. Any object impaled in the chest should not be removed, as it may be temporarily sealing a vessel or airway. The object should instead be stabilized with bulky dressings until medical personnel can take over.
Professional Medical Care and Recovery
Once the patient arrives at a medical facility, temporary field treatment is replaced by definitive medical procedures. The standard approach for resolving an open pneumothorax is the insertion of a chest tube, known as tube thoracostomy. This involves placing a flexible plastic tube into the pleural space between the ribs.
The chest tube is connected to a closed drainage system using a water seal or mechanical suction device to actively remove trapped air and re-establish negative pressure. This action allows the collapsed lung to fully re-inflate and function normally. The initial wound may also require surgical repair to close the defect in the chest wall.
The chest tube typically remains in place for a few days until the air leak has completely resolved and the lung remains fully expanded. Recovery involves monitoring the drainage system and the patient’s respiratory status, as well as managing the tube insertion site to prevent infection. With prompt intervention and definitive medical care, the prognosis for a patient with a sucking chest wound is favorable, though recovery may involve temporary restrictions on activities that stress the lungs.