Penetrating Trauma - The Hole Story

Warning

This document is intended for use in Laingholm Volunteer Fire Brigade's refresher sessions held by the First Response Unit. It is not written by a doctor and should not be considered as general medical advice for the public. Criticism from the well-informed is welcome. - Vik Olliver

Overview

A penetrating injury is basically caused by an object which has enough oomph to break through the body's surface. Once inside, the amount of trauma depends on the amount of energy transferred into the body, and the area over which it is transferred. Such injuries often draw a good crowd.

In Laingholm, we generally deal with low-velocity objects doing the penetrating. In US textbooks, they have a somewhat more comprehensive attitude, and classify injuries into three types: Low-, medium- and high-velocity injuries. The difference is basically in the amount of energy put into the poor old patient.

Low-Velocity Injury

This is the usual kid-impaled-on-an-object scenario, but also covers things like knife attacks, people going through plate glass, treading on things, putting a garden implement through a limb, lousy use of a chisel, bits flung from lawnmowers etc. It probably also covers open fractures, where the bone has broken and penetrated through from the inside.

It is important to try to find out the dimensions of the penetrating object, though it shouldn't be removed to check if it is still in the wound. The hospital staff will take a different course of action if someone receives an abdominal wound with a Stanley knife, as to one inflicted with a dagger. The former is unlikely to have caused internal damage, the latter almost certainly has.

Bear in mind that an injury to the back or neck may also have c-spine implications.

Medium-Velocity Injury

This is the realm of incidents involving handguns, high-powered slug guns, arrows from real men's bows, and bits of things that blew up. The gist is that these objects are going to inflict a certain amount of damage when they get inside that extends around the hole they make. Think of it as a very bad internal bruise. The bigger the area of contact, the bigger the bruise. The faster the object, the deeper it goes.

The main difference in treatment is that the object is generally going to be deeply buried in the patient. With a particularly enthusiastic projectile, there will be an entry hole and one or more exit holes, depending on whether the projectile stayed together in transit or broke up on the way through.

If a medium-velocity projectile strikes bone, it may knock many bits off and push them away from the original injury site. This also increases soft-tissue trauma by a sort of shrapnel effect.

With shotgun injuries, the range at which the injury was inflicted from is important. Small shot slows down relatively quickly, but has considerable initial energy. A close-range blast is like a shrapnel bomb going off near the patient, with some areas being hit by pellets multiple times. While a long-range shot may only pepper them with a few holes and small bruises. Shotguns may also fire solid or large shot, which behave more like rifle bullets.

Medium-velocity penetrating trauma may penetrate the patient all the way through the chest or abdomen, and so the possibility of a spinal injury may need to be taken into account even for a hole in the front end, particularly at close range (possibly indicated by powder burns or powder "tattoos").

High-Velocity Injury

Now we're talking people being shot with military firearms or something like a 30-30 or .223 hunting rifle. These use a fast, relatively long projectile that destabilizes in soft tissue. The projectile strikes at such great speed that it converts body fluids to steam, blasting apart a channel far wider than the projectile. This effect is called cavitation, and if carried on to the exit point forms a stellate or star-shaped exit wound.

Obviously, any bone encountered by the projectile ends up in lots of little mobile bits. These will add to any bleeding and tissue damage.

General Treatment

Safety, safety, safety. Make sure no more of the objects are flying your way. Keep the patient still and quiet. Do a primary survey and consider c-spine injuries. Put on O2 if there are breathing difficulties or significant blood loss. Consider internal bleeding (mid-chest injuries may bleed above and below the diaphragm) , so monitor and check for shock. While assessing wound, consider additional injuries suggested or implied by the mechanism of injury - the lady may have accidentally shot herself in the leg, but did she do it when she fell out of a tree? Where's the exit hole? Is this injury going to affect the airway?

Impaled Objects

Generally these are low-velocity items, except for arrows. As the object itself is of unknown shape and is plugging a bleeding hole; we are not expected or encouraged to remove it. There are always exceptions of course, such as when the object is embedded in the cheek or neck and is obstructing an airway.

Treatment is technically the same in all cases:

If practical, hold the object still to prevent further injury.
Cut clothing etc. from around the wound, trying not to move the object.
Apply pressure to the wound edges to stop bleeding.
Pack dressings around the object to prevent movement. Bandage in place.

This is a job for the doughnut bandage. A dying art but a useful technique. Twist up a triangular bandage/rag as if you're going to flick someone with a tea towel. Form about a third into a ring, and wrap the rest round and round through the hole to keep it together.

Avoid cutting the object off if practical, because they don't half jump around when you do, and may add to the injury. Your call.

.25 ACP head wound CT Scan showing displaced skull This is one of the more impressive examples of secondary injuries that I managed to find to illustrate the point of hidden effects of penetrating trauma. In this example, the patient was hit in the head with a .25 ACP round while inebriated. The bullet could be seen by the trauma team on the surface of the skull (the .25 ACP is a fairly weak round) and was easily plucked off. However, on closer examination with a CT scan, the round was revealed to have displaced many fragments bone from the inside of the skull into the brain and required urgent medical attention. It''s a bit like a Newton's Cradle effect with the incoming ball being the bullet, and the outgoing ball being the inside of the skull.

Wounds With No Visible Object

Bear in mind that it may be in there. Your "exit wound" may be another entry wound.

Assure yourself that the patient is breathing and can continue to do so. ABC is the number one priority still.
Expose the injury site(s). Clear clothing, debris, blood etc. as required to get a good look.
Control the bleeding with direct pressure, elevation or only if you must, a tourniquet. Do not apply tourniquets around the neck.
Make sure you haven't missed any injuries.
Stop crud from entering the wound. Wipe from the centre out. Wash with saline if necessary but don't pluck bits out.
Bandage wound with dry dressings, bandage, and check distal pulse.
Lots of TLC and reassurance.
Watch for symptoms of shock.

Note that medium-velocity bullets in non-critical areas will often be left where they are these days.

Chest Injuries

Penetrating wounds to the chest may be "open" in that they let air into the chest cavity. This calls for the "3-sided occlusive dressing trick" of taping an airtight patch - typically the sterile side of a clear combi dressing wrap - over the injury. Wide tape is used, but only on 3 sides. The downward-pointing edge is left open, and the contrivance forms a crude flap-valve. Provided there is no spinal injury suspected, the patient may assume any comfortable position. If the lung collapses, incline to the injured side - it is not necessary to lay the patient right down.

Evisceration, or He Had A Lot Of Guts

Do not poke at or attempt to replace any organs hanging out of an open abdominal wound. Do not poke your finger in the hole, even if you've never done it before and want to know what it's like.

Keep the organs moist with sterile saline. Avoid covering with dry or absorbant materials, which will stick, turn to fluff, and make you unpopular with the surgeon. Loosely cover the wet dressing with an occlusive dressing secured on all sides. Use glad-wrap (clingfilm to the Poms), split saline bags, anything clean and airtight. Transparent coverings let you see what's going on in all its gory detail. However, it is a good idea to cover the protected injury site with towels, blankets etc. to keep it warm.

Finally, flex the patient's knees if no spinal injury is suspected. This makes them more comfortable and reduces tension on the abdominal muscles. Add a pillow or two as well as the usual blankets. Monitor for shock, pack into ambulance, and go home for a large, stiff drink.