Tension pneumothorax—air accumulating in the pleural space outside the lungs, compressing the heart and collapsing lung tissue—is the second leading cause of potentially preventable death in combat trauma. A penetrating chest wound from a gunshot or edged weapon creates an open pathway for air to enter the thoracic cavity on each breath, rapidly building lethal pressure. Chest seals and nasopharyngeal airways directly address the A (Airway) and R (Respiration) steps of the MARCH protocol, and they belong on every serious plate carrier medical loadout right alongside the tourniquet that handles massive hemorrhage.
Why Chest Seals and Airway Devices Are Non-Negotiable
A tourniquet stops extremity bleeding—the leading preventable killer. But the moment a projectile or blade enters the chest cavity, hemorrhage control alone is insufficient. An open pneumothorax (“sucking chest wound”) needs an occlusive barrier that seals on inhalation yet vents excess air on exhalation to prevent the wound from converting to a tension pneumothorax. Meanwhile, a casualty who loses consciousness or enters respiratory distress may lose the ability to maintain their own airway. Without intervention, the tongue and soft tissue obstruct the airway and the patient suffocates even if the chest wound is sealed.
These two problems—chest cavity compromise and airway loss—are why every fill kit sold for the MED-T, MED-H, and Pocket MED-C pouches includes both a vented chest seal and (where the pouch size permits) a nasopharyngeal airway. The components are lightweight and flat-packing, meaning there is no legitimate excuse to leave them out of a carrier-mounted IFAK.
Vented Chest Seal Options
All chest seals carried serve the same core function: occlude the wound, vent trapped air, prevent tension pneumothorax. The differences lie in valve design, adhesive performance, and packaged size.
NAR HyFin Vent Chest Seal
The HyFin Vent is the most widely fielded option. Its patented three-channel pressure-relief vent design allows air to escape the chest cavity while blocking re-entry. The standard version measures 6″ × 6″ and ships in a twin-pack so you can treat both an entry and an exit wound—or two separate penetrating injuries on one patient. The large red pull tab allows single-step peel-and-apply deployment and doubles as a handle for “burping” the wound (manually lifting the seal to release trapped air if the valve clogs with blood). The adhesive gel is designed to stick through sweat, blood, and body hair—conditions that defeat lesser seals.
NAR HyFin Vent Compact
The compact version is approximately 25 percent smaller (4.75″ × 4.75″) at roughly 1.55 oz packaged weight. It uses the same three-channel vent and advanced adhesive as the standard but packs into a smaller cube, making it the default chest seal in the MED-T and MED-H fill kits as well as the Pocket IFAK via the ITRK EDC kit. For plate carrier integration where pouch real estate matters, the compact version is the preferred choice.
Safeguard Medical Sentinel Chest Seal
The Sentinel takes a different approach with a multi-layer reservoir design that channels blood toward the valve to prevent clogging while simultaneously venting air. A two-part peel process enables controlled, one-handed application and reduces the chance of the adhesive sticking to itself mid-deployment. With a deployed diameter of 6.5″ and a weight of only 1 oz, it is the lightest option. The Sentinel is CoTCCC-compliant and ships in the Pocket MED-C fill kit.
SAM Medical Valved 2.0
The SAM seal uses a rigid dome-shaped valve that remains patent even under heavy body armor pressure—a relevant consideration when treating a casualty who is still wearing plates. Large side vents minimize obstruction from blood clots or tissue. Like all options listed here, it is CoTCCC-preferred.
Choosing between seals comes down to kit size and deployment preference. The HyFin Vent Compact is the default for carrier-mounted IFAKs due to its small cube. The SAM Valved 2.0 offers the most robust valve under armor pressure. The Sentinel is the lightest single unit. Any CoTCCC-listed vented seal that is actually carried is preferable to one left at home.
Nasopharyngeal Airways
A nasopharyngeal airway (NPA) is a soft, flexible tube inserted through the nostril into the nasopharynx to maintain an open airway in a semi-conscious or unconscious patient. Unlike an oropharyngeal airway (OPA), the NPA is tolerated by patients with an intact gag reflex, making it far more practical in field conditions where the casualty’s level of consciousness is uncertain or fluctuating.
NAR Pre-Lubricated NPA
Sized at 28 French (appropriate for most adults), the NAR NPA comes pre-lubricated with a water-based lubricant rated to −5°F, eliminating the need to carry a separate lube packet. The rounded bevel tip and soft, latex-free material reduce the risk of nasal passage damage during insertion. At 0.02 lbs, it adds virtually nothing to kit weight. It is included in the MED-H and MED-T fill kits.
Safeguard Medical Pre-Lubricated NPA
Also 28 French and pre-lubricated, the Safeguard variant features a low-profile tab that is easier to tape to the nose post-insertion than the NAR version. Packaging follows MARCH protocol iconography with simple visual cues for quick identification under stress—a meaningful advantage when you are working a casualty in poor light or with gloved hands. It carries an 8-year shelf life.
NPA placement within the MARCH sequence: Airway is addressed after massive hemorrhage is controlled. Once tourniquets are applied and the patient is no longer exsanguinating, the airway is assessed. If the patient is unconscious or semi-conscious and cannot maintain their own airway, the NPA is inserted. The next step is Respiration: inspect for penetrating chest wounds and apply chest seals as needed. In practice, assessment and treatment often overlap—especially when working alone—but the prioritization framework keeps the responder from fixating on a chest wound while the patient bleeds out from an extremity.
Needle Decompression: The Next Step
Both the MED-T and MED-H fill kits include two NAR Enhanced ARS 14-gauge needle decompression devices. These address tension pneumothorax that has already developed—when a chest seal alone is not enough and air pressure is compressing the heart and great vessels. The fenestrated catheter design is nearly twice as successful as non-fenestrated alternatives in clinical research. Centimeter markings with contrasting colors provide depth control, and the flexible catheter reduces kinking after insertion.
Needle decompression is a higher-skill intervention than chest seal application or NPA insertion. It requires training to recognize the signs of tension pneumothorax (progressive respiratory distress, tracheal deviation, absent breath sounds on one side, hypotension) and to execute the procedure without causing additional harm. This is the kind of skill covered under TCCC fundamentals—training that should be pursued before the device is carried.
Integration on the Plate Carrier
Chest seals and NPAs need to be accessible without removing the plate carrier. The standard approach is to stage them inside a dedicated medical pouch mounted where either the wearer or a buddy can reach them. The medical pouch options page covers mounting positions in detail, but the short version is: the pouch goes where you can reach it with either hand, typically on the rear cummerbund panel or a side-mounted MOLLE field.