A chest seal is a specialized occlusive dressing designed for immediate, life-saving trauma care when a penetrating injury to the chest wall occurs. This adhesive patch is engineered to create an airtight seal over the wound, preventing atmospheric air from being drawn into the chest cavity. The proper and rapid application of a chest seal is a time-sensitive intervention that can prevent a tension pneumothorax, which is one of the most common causes of preventable traumatic death. Understanding how to use this tool correctly is important, but this information is not a substitute for formal, hands-on medical training.
Understanding Penetrating Chest Trauma
A penetrating injury to the chest, often called a “sucking chest wound,” creates an open pathway between the outside air and the pleural space, the area between the lung and the chest wall. Normally, this space maintains a negative pressure relative to the atmosphere, which keeps the lung fully inflated as the chest expands during inhalation. When a hole in the chest wall is present, air rushes into the chest cavity through this wound instead of through the trachea, disrupting the necessary pressure gradient for proper breathing.
This influx of air leads to a pneumothorax, or a collapsed lung, because the air accumulating in the pleural space presses on the lung tissue. The greater danger is the development of a tension pneumothorax, which occurs when a flap of tissue or blood clot creates a one-way valve effect at the wound site. Air is continually drawn into the chest cavity but cannot escape, causing pressure to build rapidly.
This mounting pressure can push the mediastinum—the central compartment of the chest containing the heart and major blood vessels—to the opposite side, compressing the uninjured lung. This severely impairs the heart’s ability to fill with blood, quickly leading to circulatory collapse and death. Sealing the wound is a time-sensitive measure.
Selecting the Right Chest Seal
Chest seals are generally categorized into two types: vented and non-vented, with the vented seal being the preferred choice for managing an open chest wound. A non-vented, or purely occlusive, seal is a simple adhesive patch that completely blocks the entry of air into the wound. While it stops air from entering, it provides no mechanism for trapped air already inside the chest cavity to escape.
A vented chest seal is engineered with a one-way valve or multiple channels that allow air and fluid to escape from the chest cavity while preventing external air from being sucked in. This one-way mechanism works to mitigate the risk of a tension pneumothorax by regulating the pressure inside the pleural space. If a vented seal is unavailable, a non-vented seal can be used, but it requires much closer monitoring.
Key features to look for in any chest seal include a strong adhesive that can stick effectively to wet or bloody skin and a size large enough to cover the wound and surrounding area completely.
Step-by-Step Application Procedure
The application of a chest seal must be performed quickly and methodically to minimize air accumulation and maximize the chance of survival. First, ensure the scene is safe and you are wearing protective gloves to minimize exposure to bloodborne pathogens. Immediately expose the wound by tearing or cutting away clothing, and quickly inspect the patient’s entire torso for any other potential entry or exit wounds, as all defects must be sealed.
Before applying the seal, wipe away any excessive pooling of blood or fluid from around the wound site. Do not waste time attempting to completely sterilize or dry the area; the priority is to establish a good seal as rapidly as possible, and modern seal adhesives are designed to adhere in wet conditions. The most important step is to apply the seal immediately after the patient fully exhales.
Applying the seal during exhalation ensures that the chest cavity holds the least amount of air, minimizing the volume of trapped air that could lead to pressure buildup. Place the center of the seal directly over the wound, ensuring the entire defect is covered with an adequate margin on all sides.
Firmly press down on the entire surface of the seal, especially around the edges, to ensure a complete and airtight adherence to the skin. If the patient has both an entry and an exit wound, both must be sealed, ideally using a vented seal on the larger or most obvious sucking wound.
Ongoing Patient Management After Sealing
After the chest seal is securely in place, the care shifts immediately to continuous monitoring of the patient’s respiratory status. Even with a vented seal, the patient can still develop a tension pneumothorax, so observation is continuous. Look for signs of worsening respiratory distress, which include increased difficulty breathing, a rapid heart rate, or a bluish tint to the lips or fingernails.
If a vented seal was used, periodically check the vent channels to ensure they have not become clogged with clotted blood or debris, which would prevent air from escaping. If the patient’s condition rapidly declines and tension pneumothorax is suspected, the seal may not be venting effectively. In this case, or if a non-vented seal was initially used, you must “burp” the wound to release the trapped air.
To burp a non-vented or blocked seal, gently lift one edge of the dressing to allow the built-up air pressure to escape from the chest cavity. This action should be performed during the patient’s exhalation, and the seal must be immediately reapplied completely to maintain the one-way valve principle. Finally, position the patient in a semi-reclined position or on the injured side, if possible, to maximize the function of the uninjured lung. Immediate and rapid transport to definitive medical care is necessary, as the chest seal is only a temporary stabilizing measure.