a. Prepare the Plastic Wrapper. Cut open one end of the plastic wrapper of a
field dressing. Remove the inner packet (the field dressing wrapped in paper) and put it
aside. Continue to cut around the edges of the plastic wrapper until a flat surface is
created. This plastic wrapper will be used to make the airtight seal.
If there is both an entry wound and an exit wound, the plastic wrapper may be
cut to make two seals if the wounds are not too large. The edges of the
sealing material should extend at least two inches beyond the edges of the
b. Have Casualty Exhale. Tell the casualty to exhale (breathe out) and hold his
breath. This forces some of the air out of the chest wound. The more air that can be
forced out of the chest before the wound is sealed, the better the casualty will be able to
breathe after the wound is sealed.
The casualty can resume normal breathing after the wound is sealed.
If the casualty is unconscious or cannot hold his breath, place the plastic
wrapper over the wound after his chest falls but before it rises.
c. Apply and Tape the Airtight Material Over Wound.
(1) Place the inside surface of the plastic wrapper (the side without printing)
directly over the hole in the chest to seal the wound.
(2) Check the plastic wrapper to ensure that it extends at least two inches
beyond the wound edges in all directions. If the wrapper does not have a two-inch
margin, it may not form an airtight seal and may even be sucked into the wound. If the
wrapper is not large enough or is torn, use foil, a poncho, cellophane, or other airtight
material to form the seal.
(3) Tape down three edges of the plastic, usually the top edge and two side
edges. This creates a "flutter valve" effect. When the casualty inhales, the plastic is
sucked against the wound and air cannot enter the wound. When the casualty exhales,
air may be able to exit the wound through the untaped (bottom) edge of the plastic. See
If there are two wounds affecting the same lung, apply airtight material to the
other wound and tape down all four sides so that no air can enter or escape