Vented vs Non-Vented Chest Seal: Critical Differences Explained

There are two main types of chest seals: vented and non-vented. Each works differently and is chosen based on the injury and the patient’s condition. A chest seal is used to cover open chest wounds, especially sucking chest wounds where air enters the chest cavity and threatens lung collapse. 

Understanding the difference between a vented chest seal vs non-vented one helps EMS providers make quick, informed decisions in the field. Let’s look at how each type works, when to use them, and what makes one better suited than the other to specific emergencies.

What Is a Vented Chest Seal?

A vented chest seal features a one-way valve or multiple channels that allow air and fluids to escape from the chest cavity but prevent air from entering. This design helps manage pressure within the pleural space, reducing the risk of life-threatening tension pneumothorax—a condition where trapped air increases chest pressure and impairs lung function.

What Is a Non-Vented Chest Seal?

A non-vented chest seal is a simple, airtight dressing without a valve or channels. It creates a sealed environment over the wound, preventing air from entering the chest cavity. This occlusive chest seal doesn’t allow trapped air to escape, which often leads to complications if air accumulates.

How Do Chest Seals Work?

A chest seal restores a closed breathing system by covering chest wounds to stop air from entering. A penetrating wound anywhere between the neck and navel allows air to enter the pleural cavity with each breath. The trapped air prevents the lung from expanding, leading to respiratory distress and potentially lung collapse. 

Vented seals let trapped air or fluid escape, while non-vented seals do not. This difference is what makes choosing the right seal so important.

Multi-vent designs, like the HyFin® Vent Compact Chest Seal Twin Pack, release air in multiple directions, ensuring they work even if not perfectly centered over the wound. Wells et al. (2025) found that laminar vent designs with wider and more numerous channels improved flow rates and reduced blockages, allowing for more efficient evacuation of air and fluid.

Chest Seal Application

The chest seal is applied just after the patient exhales, when the chest holds the least air. When applied correctly, both vented and non-vented seals buy time until advanced care is available. If respiratory distress or pressure builds under a non-vented seal, lift one edge to release air (“burp” it) and then reseal.

Advantages of Vented Chest Seals

Vented chest seals provide key benefits that help manage air and pressure in chest wounds:

• One-way valves or channels allow trapped air to escape while preventing air from entering the chest cavity.
• Helps prevent tension pneumothorax by regulating pressure inside the pleural space.
• Recommended by Tactical Combat Casualty Care (TCCC) guidelines for open chest wounds (Section 5.b).
• Suitable for injuries where air accumulation is a concern.

A 2016 study published in Injury found that the HyFin® chest seal, which features hydrogel-based adhesives, maintained strong adhesion after exposure to blood, debris, and extreme temperatures, demonstrating reliable performance in demanding conditions.

Disadvantages of Vented Chest Seals

Vented chest seals have some limitations you should consider:

• The more complex design is prone to failure if the valve becomes blocked, which is why multi-channels are better.
• Requires careful application to ensure the valve works correctly.
• More expensive than non-vented options.

Advantages of Non-Vented Chest Seals

Non-vented chest seals provide simple, reliable benefits for managing open chest wounds:

• The simple design with no moving parts reduces the risk of malfunction.
• Provides a secure seal to prevent air entry into the chest cavity.
• Cost-effective and easy to use in high-pressure situations.

Disadvantages of Non-Vented Chest Seals

Unvented chest seals have a few drawbacks that you should keep in mind:

• Trapped air can’t escape, increasing the risk of tension pneumothorax.
• Requires close monitoring and must be ‘burped’ or replaced if trapped air causes complications.
• Not recommended for injuries where air accumulation is a concern.

Chest Seal Selection in the Field

This table shows common scenarios EMS providers face and the chest seal type best suited for each. Use these guidelines with TCCC or EMS protocols and your judgment to stabilize the patient and prevent complications.

Improvised Chest Seal

If there’s an emergency and a commercial chest seal isn’t available, improvise using the plastic wrapper from a dressing or gauze pack. Place the sterile side over the wound, tape it on all sides, and monitor breathing until a medical-grade seal is available. When choosing a bleeding control kit, make sure it includes chest seals for open chest wounds to prevent the need for an improvised solution.

Watch for Rising Chest Pressure

Keep watching how the patient breathes, no matter what you used to seal the wound. If the patient starts getting winded, drowsy, or confused, pressure is building inside the chest. Trapped air will quickly collapse the lung if it isn’t released.

Check the seal right away, following these recommendations:

• For vented seals, wipe away any blood or debris blocking the vent to let air escape. 
• For non-vented or improvised seals, burp it and then reseal firmly. 
• Replace a seal if it won’t stay airtight. If symptoms don't ease, prepare to do a needle decompression as directed by TCCC guidelines or EMS protocols.

Your Bleeding Control Kit Needs Chest Seals

Every bleeding control kit should include chest seals for managing open chest wounds. The choice between vented and non-vented seals depends on the wound type, patient condition, transport situation, and available supplies. Both play a vital role in stabilizing chest injuries until advanced care arrives.

Vented seals release trapped air to prevent tension pneumothorax, while non-vented seals block further air entry to reduce the risk of lung collapse. Effectiveness depends on proper application and monitoring. Keep both types in your kit (buy vented chest seals here) and know when to use them to promote stabilization and prevent rapid decline.