Occlusive Dressing
A dressing that creates an airtight, waterproof seal over a wound, used primarily for penetrating chest trauma to prevent air from entering the pleural space.
In the Field
The occlusive dressing is the predecessor to the modern vented chest seal. The principle is the same: close the hole in the chest wall so air cannot enter the pleural space with each breath. The catch is that fully occlusive dressings can convert an open pneumothorax into a tension pneumothorax by trapping air inside the chest. Modern commercial chest seals are vented to allow trapped air to escape, which is why they have replaced improvised plastic-and-tape occlusive dressings as the standard of care. The terminology still appears in older protocols and training materials, so knowing what it means matters for procurement officers comparing legacy specifications to current ones.
Common Mistake
Applying a fully occlusive non-vented dressing to a penetrating chest wound without monitoring for tension pneumothorax development under the seal.
Technical Detail
An occlusive dressing is any dressing material that forms an airtight, waterproof barrier over a wound. The term is most commonly used in the context of penetrating chest trauma, where the goal is to prevent air from entering the pleural space through an open chest wall wound. See the Open Pneumothorax entry for the underlying clinical problem.
Types of occlusive dressings:
Improvised occlusive dressings. Plastic wrap, defibrillator pad packaging, sandwich bag material, or other readily available impermeable material taped over a chest wound. Historically the standard before commercial chest seals became widely available. Improvised dressings should be taped on three sides only, leaving the fourth side open as a one-way release valve to prevent tension pneumothorax development.
Commercial non-vented chest seals. Adhesive seals designed specifically for chest wound application without integrated venting. Earlier generation devices that have largely been superseded by vented designs.
Commercial vented chest seals. Adhesive seals with integrated one-way valves that allow trapped pleural air to escape during exhalation while preventing air entry during inhalation. The current standard of care for open pneumothorax management. CoTCCC-recommended vented chest seals include the Hyfin Vent, SAM Chest Seal, and Russell Chest Seal. See the Chest Seal entry.
Why venting matters. The fundamental problem with a fully occlusive dressing on a penetrating chest wound is the risk of converting open pneumothorax into tension pneumothorax. The mechanism:
Air enters the pleural space through the open wound during the patient's breathing.
The fully occlusive dressing closes the wound, preventing further air entry.
If air is already in the pleural space at the time the dressing is applied, or if air leaks into the pleural space from injured lung tissue, that air has no path to escape.
Pressure progressively builds in the pleural space, compressing the lung, the heart, and the great vessels.
The patient develops tension pneumothorax with progressive respiratory and cardiovascular collapse.
Vented chest seals address this by providing a one-way valve. Air can leave the pleural space but cannot enter through the dressing. This maintains the occlusive function (preventing further air entry through the wound) while allowing trapped air to escape.
Three-sided taping. The improvised solution to the same problem is taping a non-vented occlusive material on three sides only, leaving the fourth side open as an escape route. This works in principle but has limitations:
The taping must be performed correctly, with the open side oriented to function as a valve.
Patient positioning, blood, sweat, and movement can compromise the function of the open side.
The improvised approach is less reliable than a purpose-designed vented seal.
Three-sided improvised occlusive dressings remain a valid backup when commercial chest seals are unavailable, but they are not equivalent to vented chest seals.
Other uses of occlusive dressings. Outside of penetrating chest trauma, occlusive dressings have other applications:
Eviscerated abdominal wounds. An occlusive dressing (often moistened sterile dressing covered with plastic or foil) is used to cover exposed organs to prevent drying and contamination during transport. See the Evisceration entry.
Burn wound coverage. Selected burn protocols use occlusive dressings for specific clinical purposes.
Sucking neck wounds. Occlusive dressings can be used to seal penetrating neck wounds where air entry is a concern, with attention to avoiding airway compression.
Some IV catheter dressings. Some modern IV catheter dressings include occlusive properties for infection prevention.
Procurement implications. The shift from non-vented to vented chest seals reflects current evidence-based practice. Procurement specifications should:
Specify CoTCCC-recommended vented chest seals as the primary chest seal product.
Include multiple chest seals per IFAK to allow application to both entry and exit wounds when present.
Maintain sufficient adhesive performance under field conditions (wet skin, blood, sweat, hair).
Include training in chest seal application and tension pneumothorax recognition.
Older specifications that call for "occlusive dressing" without specifying vented chest seal reflect outdated equipment lists and should be updated.
Types of occlusive dressings:
Improvised occlusive dressings. Plastic wrap, defibrillator pad packaging, sandwich bag material, or other readily available impermeable material taped over a chest wound. Historically the standard before commercial chest seals became widely available. Improvised dressings should be taped on three sides only, leaving the fourth side open as a one-way release valve to prevent tension pneumothorax development.
Commercial non-vented chest seals. Adhesive seals designed specifically for chest wound application without integrated venting. Earlier generation devices that have largely been superseded by vented designs.
Commercial vented chest seals. Adhesive seals with integrated one-way valves that allow trapped pleural air to escape during exhalation while preventing air entry during inhalation. The current standard of care for open pneumothorax management. CoTCCC-recommended vented chest seals include the Hyfin Vent, SAM Chest Seal, and Russell Chest Seal. See the Chest Seal entry.
Why venting matters. The fundamental problem with a fully occlusive dressing on a penetrating chest wound is the risk of converting open pneumothorax into tension pneumothorax. The mechanism:
Air enters the pleural space through the open wound during the patient's breathing.
The fully occlusive dressing closes the wound, preventing further air entry.
If air is already in the pleural space at the time the dressing is applied, or if air leaks into the pleural space from injured lung tissue, that air has no path to escape.
Pressure progressively builds in the pleural space, compressing the lung, the heart, and the great vessels.
The patient develops tension pneumothorax with progressive respiratory and cardiovascular collapse.
Vented chest seals address this by providing a one-way valve. Air can leave the pleural space but cannot enter through the dressing. This maintains the occlusive function (preventing further air entry through the wound) while allowing trapped air to escape.
Three-sided taping. The improvised solution to the same problem is taping a non-vented occlusive material on three sides only, leaving the fourth side open as an escape route. This works in principle but has limitations:
The taping must be performed correctly, with the open side oriented to function as a valve.
Patient positioning, blood, sweat, and movement can compromise the function of the open side.
The improvised approach is less reliable than a purpose-designed vented seal.
Three-sided improvised occlusive dressings remain a valid backup when commercial chest seals are unavailable, but they are not equivalent to vented chest seals.
Other uses of occlusive dressings. Outside of penetrating chest trauma, occlusive dressings have other applications:
Eviscerated abdominal wounds. An occlusive dressing (often moistened sterile dressing covered with plastic or foil) is used to cover exposed organs to prevent drying and contamination during transport. See the Evisceration entry.
Burn wound coverage. Selected burn protocols use occlusive dressings for specific clinical purposes.
Sucking neck wounds. Occlusive dressings can be used to seal penetrating neck wounds where air entry is a concern, with attention to avoiding airway compression.
Some IV catheter dressings. Some modern IV catheter dressings include occlusive properties for infection prevention.
Procurement implications. The shift from non-vented to vented chest seals reflects current evidence-based practice. Procurement specifications should:
Specify CoTCCC-recommended vented chest seals as the primary chest seal product.
Include multiple chest seals per IFAK to allow application to both entry and exit wounds when present.
Maintain sufficient adhesive performance under field conditions (wet skin, blood, sweat, hair).
Include training in chest seal application and tension pneumothorax recognition.
Older specifications that call for "occlusive dressing" without specifying vented chest seal reflect outdated equipment lists and should be updated.