Improvised Chest Seal

When you need a chest seal

• A wound to the chest that makes a sucking or hissing sound when the person breathes
• Bubbles forming at a chest wound
• The person is struggling to breathe after a chest injury
• Any penetrating wound between the neck and the navel on the front or back of the torso

This is a life-threatening emergency. A sucking chest wound lets air into the chest cavity and can collapse a lung.

Commercial chest seal

If you have one (like a HyFin or SAM chest seal):

1. Peel the backing
2. Place it directly over the wound
3. Press firmly to seal all edges
4. If it has a valve, ensure the valve is positioned correctly

Improvised chest seal

You need something airtight and smooth:

• Plastic bag (shopping bag, zip-lock)
• Cling wrap / plastic wrap
• Aluminium foil
• A latex or nitrile glove cut flat
• The wrapper from a bandage or gauze packet

Steps

1. Cut the material to a square at least 5cm larger than the wound on all sides
2. Wipe blood and sweat away from the skin around the wound (the seal needs to stick)
3. Place the plastic over the wound while the person breathes out (this reduces air in the chest)
4. Tape three sides: leave the bottom side open. This creates a flutter valve: air can escape but not enter
5. If no tape, have someone hold it in place with firm pressure

Why three sides, not four?

Taping only three sides creates a one-way valve. When the person breathes in, the plastic seals against the wound. When they breathe out, air trapped in the chest can escape through the untaped edge. If you seal all four sides, pressure can build up and make things worse.

After sealing

• Place the person in the recovery position on their injured side (wound side down)
• Monitor their breathing closely
• If breathing gets worse after sealing, briefly lift the untaped edge to release trapped air, then reseal
• Get to a hospital immediately; this is a temporary measure