In the Field
Open pneumothorax is the classic sucking chest wound. The reason a chest seal exists. You have a penetrating chest wound and you can hear or see air moving through it. The basic intervention is closing the wound to stop air from entering. The detail is doing it with the right device, in the right way, while watching for the wound to convert into a tension pneumothorax under the seal you just placed.
Common Mistake
Applying a fully occlusive non-vented seal to an open pneumothorax without monitoring for conversion to tension pneumothorax.
Technical Detail
An open pneumothorax occurs when a penetrating chest wound creates a direct communication between the outside atmosphere and the pleural space. With each breath, air can move through the wound rather than through the airway, equalizing pressure between the chest cavity and the outside, and preventing normal lung expansion on the affected side.
Why it is called a sucking chest wound. With each inhalation, the negative pressure created by the diaphragm draws air through the open wound, sometimes producing an audible sucking or hissing sound. With each exhalation, air may escape through the wound. The sound and visual movement of air through the wound are a hallmark of significant open pneumothorax.
Field treatment. The intervention is to close the wound to prevent further air entry while allowing trapped air to escape:
Apply a vented chest seal directly over the wound. The seal adheres to the chest wall and creates an occlusive barrier against further air entry, while the integrated valve allows air trapped in the pleural space to escape during exhalation.
Apply seals to both entry and exit wounds when present. Penetrating projectiles often produce both, and an unsealed exit wound continues to admit air.
Monitor the patient for conversion to tension pneumothorax. A chest seal that closes the wound but allows air to accumulate inside the pleural space can produce a tension pneumothorax. Worsening respiratory distress, falling oxygen saturation, hypotension, and rising anxiety after seal placement are warning signs.
If signs of tension pneumothorax develop, lift the seal briefly to release trapped air ("burping" the seal) and reseal. Persistent tension pneumothorax requires needle decompression, which is a provider-level intervention.
Improvised seals. When a commercial chest seal is not available, occlusive material (plastic wrap, sandwich bag, defibrillator pad packaging) can be taped over the wound. Tape only three sides. The fourth side is left open as a one-way escape valve. A four-sided fully occlusive improvised seal carries a high risk of converting an open pneumothorax to a tension pneumothorax.
Approved commercial seals. CoTCCC-approved vented chest seals include the Hyfin Vent, SAM Chest Seal, and Russell Chest Seal. These are standard contents of IFAKs and aid bags.
