In the Field
Most people worry about vented versus non-vented until they are standing over a patient trying to get anything to stick to a bloody chest. In the field, adhesion matters more than design. The moment you need a chest seal is not subtle. Mechanism of injury, respiratory distress, and a wound that should not be there. When that moment hits, you are either glad it is staged in your kit or you are improvising with something that was never meant for the job.
Common Mistake
Choosing a seal based on vent design when the real-world failure point is adhesion.
Technical Detail
A chest seal is an occlusive dressing designed to cover penetrating thoracic trauma. The clinical concern is pneumothorax, and specifically tension pneumothorax, a condition where air accumulates in the pleural space, compresses the lungs and heart, and can be fatal if untreated. Chest seals do not prevent tension pneumothorax. They limit air entrainment through the wound and reduce the rate at which air accumulates, but tension pneumothorax can still develop and requires continued monitoring.
Current TCCC and TECC guidelines call for vented chest seals over non-vented models. A vented seal allows air to escape during exhalation while preventing air from entering during inhalation, which may reduce the risk of tension pneumothorax compared to non-vented seals. Seals should be applied to both entry and exit wounds when present.
Patients with chest seals in place must be continuously monitored for signs of tension pneumothorax, including worsening respiratory distress, hypotension, jugular venous distention, and tracheal deviation. If signs of tension develop, the seal may need to be lifted ("burped") to release trapped air, and needle decompression escalation may be required per provider protocol.
Commercial field-approved chest seals include the Hyfin Vent, SAM Chest Seal, and Russell Chest Seal. A chest seal that does not adhere reliably in wet or bloody conditions is not field-usable.
Improvised chest seals (plastic wrap, credit cards, sandwich bags) are sometimes taught as last-resort options. If improvising, the occlusive material should be taped on three sides only, leaving the fourth side open as a crude one-way valve to allow trapped air to escape. A four-sided tape job on an improvised seal creates a fully occlusive cover and carries a higher risk of tension pneumothorax development than no seal at all. Improvised options should never replace a commercial vented chest seal when one is available.
