Tension Pneumothorax — The Chest Injury That Kills in Minutes

     You are the help until help arrives. Trauma does not play by the rules of the emergency department. While massive hemorrhage is the most visible threat to life in the wilderness, there is a silent, invisible killer that can take a life just as quickly: the tension pneumothorax.

     As board-certified Emergency Medicine Physicians, we have managed countless chest traumas. We built PrepEM Wild because we know that when you are miles from the nearest hospital, a basic first-aid kit won't cut it. Today's Wild Dispatch covers one of the most terrifying scenarios an outdoorsman can face—a collapsed lung under pressure—and the exact steps and gear required to decompress the chest and save a life.

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The Reality of Wilderness Chest Trauma

     When most people think of chest trauma, they picture combat scenarios or high-speed motor vehicle accidents. However, the wilderness presents its own unique set of high-probability risks. For hunters, the danger is particularly acute. Studies show that nearly 10 percent of hunters who use treestands are injured annually, making treestand falls the leading cause of hunting-related injuries [1].

     When a hunter falls 15 feet from a stand, or an overlander rolls an ATV, the blunt force impact frequently results in severe rib fractures. A fractured rib can easily puncture the lung from the inside. Alternatively, penetrating trauma from a broadhead arrow, a hunting knife, or a gunshot wound can breach the chest wall from the outside. Both scenarios can lead to a catastrophic disruption of the pleural cavity.

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Understanding the Mechanics: Open vs. Tension Pneumothorax

     To treat chest trauma in the field, you must understand the difference between a standard open pneumothorax and a lethal tension pneumothorax. The human thorax relies on a delicate balance of pressure. The lungs are enveloped by the visceral pleura, while the chest wall is lined by the parietal pleura. The space between them—the pleural cavity—maintains a slightly negative pressure that keeps the lungs expanded during breathing [2].

 

The Open Pneumothorax (Sucking Chest Wound)

     An open pneumothorax occurs when penetrating trauma creates a hole in the chest wall. Because the pressure inside the chest is lower than the atmospheric pressure outside, air is sucked into the pleural space through the wound with every breath. You will often hear a distinct "sucking" or hissing sound. As air fills the space, the lung begins to collapse. While highly dangerous, an open pneumothorax can be managed effectively if sealed quickly.

The Tension Pneumothorax (The Death Spiral)

     A tension pneumothorax is a severe progression of a pneumothorax where a one-way valve mechanism develops. Air enters the pleural space during inspiration—either through a hole in the chest wall or a hole in the lung itself—but the tissue acts as a flap, trapping the air and preventing it from escaping during expiration [3].

     With every single breath, more air is forced into the chest cavity, and the pressure escalates rapidly. This building pressure completely collapses the affected lung and begins to push the heart, the great vessels, and the trachea toward the uninjured side of the chest (a process known as mediastinal shift). As the superior vena cava is compressed, blood can no longer return to the heart. Cardiac output plummets, blood pressure crashes, and without immediate intervention, the patient will go into cardiac arrest [4].

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Recognizing the Signs in the Field

     In the wilderness, you must rely on your physical assessment skills. A patient developing a tension pneumothorax will deteriorate rapidly. Watch for the classic presentation:

• Severe Respiratory Distress: The patient is fighting for every breath and cannot get enough air.
• Absent Breath Sounds: If you place your ear against the injured side of the chest, you will hear little to no air movement compared to the healthy side.
• Hypotension and Shock: The patient will become pale, clammy, confused, and their radial (wrist) pulse will become weak or absent as their blood pressure drops.
• Distended Neck Veins (JVD): The veins in the neck may bulge as blood backs up, unable to enter the compressed heart.
• Tracheal Deviation: In late stages, you may visibly see the windpipe shifting away from the injured side of the chest.

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Field Management: The Step-by-Step Protocol

     When faced with penetrating chest trauma or suspected tension pneumothorax, follow this aggressive, step-by-step management protocol based on Tactical Combat Casualty Care (TCCC) guidelines.

Step 1: Expose and Assess

     You cannot treat what you cannot see. Immediately use heavy-duty trauma shears to cut away the patient's clothing. Inspect the entire chest, armpits, and back. Always check for an exit wound. A bullet or broadhead that enters the front of the chest often exits the back, creating two holes that must be managed.

Step 2: Seal the Box (Vented Chest Seals)

     If you find an open wound, you must seal it immediately to stop atmospheric air from being sucked into the chest. Wipe the skin around the wound quickly to remove excess blood or sweat, and apply a vented chest seal. Instruct the patient to exhale completely as you apply the seal.

     Vented seals, such as the HyFin Vent Chest Seal, feature one-way channels that allow trapped air and blood to escape the chest cavity while preventing new air from entering. If there is an exit wound, apply a second seal to the back.

Step 3: Needle Decompression (The Final Resort)

     If you have sealed the chest (or if the patient suffered blunt trauma like a treestand fall) and the patient continues to rapidly deteriorate with severe shortness of breath and signs of shock, a tension pneumothorax is likely developing. The trapped air must be released manually through a procedure called needle decompression.

     This requires a specialized 14-gauge, 3.25-inch needle and catheter. The needle is inserted into the chest cavity to vent the pressurized air, instantly relieving the pressure on the heart and lungs. The primary insertion site is the second intercostal space at the midclavicular line (just below the collarbone, in line with the nipple), inserting the needle just over the top of the third rib to avoid the neurovascular bundle [5]. Once a rush of air is heard or felt, the catheter is advanced, and the needle is removed.

Note: Needle decompression is an advanced, invasive medical procedure. It should only be performed by individuals with appropriate training when the patient is in imminent danger of death.

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Gear Up: The PrepEM Wild Hemorrhage Kit

     You cannot improvise a chest seal with a credit card and duct tape when your hands are shaking and your partner is dying. You certainly cannot improvise a 14-gauge decompression needle. You must carry the right gear.

We designed the PrepEM Wild Hemorrhage Kit specifically for these catastrophic, worst-case scenarios. It is a professional-grade trauma system that goes far beyond basic first aid.

Inside this kit, you will find the exact tools required to manage chest trauma:

• HyFin Vent Chest Seal (Twin Pack): Two vented seals to manage both entry and exit wounds simultaneously.
• 14-Gauge x 3.25” Needle Decompression Kit: The TCCC-compliant standard for relieving a tension pneumothorax, housed in a rugged protective tube.
• Heavy-Duty Trauma Shears: Essential for rapidly exposing the chest.

Because chest trauma is rarely isolated, the kit also includes the Snakestaff ETQ Gen 2 Tourniquet, WoundClot Hemostatic Gauze, and an Israeli Trauma Bandage to handle massive arterial bleeding.

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The PrepEM Wild Chest Trauma Quick-Reference

Priority	Action	Key Detail	Gear Required
1	Expose the chest	Cut away all clothing. Check the front, armpits, and back for wounds.	Trauma shears
2	Seal open wounds	Apply a vented chest seal to the entry wound. Have the patient exhale during application.	HyFin Vent Chest Seal
3	Check for exit wounds	Roll the patient and inspect the back. Seal any secondary holes immediately.	Second HyFin Vent Chest Seal
4	Monitor for Tension	Watch for severe shortness of breath, absent breath sounds, and dropping blood pressure.	Vigilance and physical assessment
5	Decompress (If Trained)	If tension pneumothorax develops and death is imminent, perform needle decompression.	14-gauge, 3.25" Decompression Needle
6	Evacuate immediately	Chest seals and needles are temporary fixes. The patient requires a surgical chest tube.	Satellite communicator / PLB

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Be Ready When It Counts

     A tension pneumothorax does not care how far you hiked in or how bad the weather is. It is a mechanical problem that requires a mechanical solution. Understanding the pathophysiology of chest trauma, carrying vented chest seals, and knowing when a needle decompression is required separates the prepared from the helpless.

Get the gear. Get the training. Be the help until help arrives.

Prepare Safely. Respond Boldly.

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References

1. Pierre, C. A., et al. "Tree stand falls: A persistent cause of neurological injury in hunters." Surgical Neurology International, vol. 5, 2014. https://pmc.ncbi.nlm.nih.gov/articles/PMC4133424/
2. Sahota, R. J., and Sayad, E. "Tension Pneumothorax." StatPearls, National Center for Biotechnology Information, 2025. https://www.ncbi.nlm.nih.gov/books/NBK559090/
3. "Tension Pneumothorax: Pathophysiology and Management." Merck Manual Professional Version, 2024.
4. Butler, F. K., et al. "Management of Suspected Tension Pneumothorax in Tactical Combat Casualty Care." Journal of Special Operations Medicine, 2018.
5. "Needle Decompression of Tension Pneumothorax Tactical Combat Casualty Care Guideline Recommendations." Defense Technical Information Center, 2012.