Knife injuries

This was written by a surgeon with Martial Arts experience on knife injuries posted on Dog Brothers Forum many years ago.

"Anyway, the upshot is killing someone with a blade isn't as easy as it looks on TV. The scene where someone gets stabbed in the belly, then looks shocked, then drops dead is unrealistic. Either a fair amount of damage needs to be done, some very vital structures injured, or a fair amount of time to pass if the wounds aren't horrendous in order for someone to die from stab or slash wounds.

There's quite a bit of variability as to how folks respond to trauma in general. Some seem to die with minimum injury and others seem to withstand huge blood loss and horrific injuries. I haven't a clue what differentiates these two populations but wish I knew...

I said it before and I'll say it again. In a conflict for my life, I would rely on a blunt force instrument to the head before a bladed weapon to just about any anatomic structure to most quickly stop a threat. It doesn't matter what level of adrenaline you've got or what drugs you may have in your system. If you're struck hard enough in the head, you're going down. Also, the long term implications of a survived head injury are (in general) worse than those of a knife wound you recover from.

Trauma and human response to trauma is very interesting. I don't know if I believe that primates and humans in particular are harder to kill. Hunting injuries to animals are typically(hopefully) quite precise and should result in a rapid humane kill. Fighting injuries to humans presenting to trauma centers are less so. I would guess those folks shot by skilled snipers die quickly, similar to hunting wounds.

Anyway, at risk of being accused of being "disturbing" again, here are some generalities for delivering fatal wounds with a bladed weapon.

First: the blade must absolutely be sharp. I've operated on plenty of folks in which a dull edge pushed structures away rather than incising them. Arteries are relatively thick walled and elastic, a dull edge will displace rather than cut them.

Second: All other things equal, a larger blade will be better.

Third: Relying on a single wound to incapacitate an opponent is a bad idea.

Anatomic considerations: The body's actually pretty well designed and protects the most important structures.
If you want to get to the heart there are two reliable ways: A very sharp and sturdy knife thrust strongly just left of the sternal border around the 4th interspace(about nipple level on a guy) will do it. Otherwise, just go under the sternum(under the xiphoid) and aim at the left shoulder. This is basically how we place a needle in the pericardium to drain fluid out from around the heart.

The flexor/medial/anterior surfaces of the extremites are where the money is. In the arm, that's the inner aspect of the upper arm, the crease at the elbow, the palmar aspect of your forearm. In the lower extremity imagine a line from the crest of your pelvis to your pubic bone. About 1/2 of the way up(usually a bit less actually) you get your femoral artery and vein. If the weapon is directed back and up into the abdomen a bit, you can get the iliac vessels. These are especially hard to get to surgically and can not easily be treated with direct pressure. The femoral artery goes medially down the thigh (there's a deep branch as well) and then behind the knee in the midline roughly. It breaks into three vessels below the knee and is no longer that great a target.

In the abdomen, you'd be trying to get to the aorta or the vena cava. This would be actually VERY difficult with anything you're likely to carry around. There are some posterior approaches taht would work, but I doubt they'd be useful in the middle of a chaotic fight. The liver occupies the right upper quadrant and is a giant target. A large knife and multiple wounds would be necessary and there no guarantee whatsoever that this would end a fight quickly.

Stab wounds to the chest in general are likely to get the lungs which can result in collapse(by pneumo or hemothorax) and bleed quite a bit in general. Here, you might actually do well with a smaller knife, since if the opening in the chest is big enough, they won't get what's called a tension pneumothorax. In a similar vein, a small wound to the heart, like an ice pick doesn't kill by bleeding. The blood gets in the sac around the heart, and when the pressure builds up the heart can't fill. If it can't fill, it can't pump and that's that.

The neck is a tried and true target for bladed attacks. A tracheal injury in and of itself may well do nothing.
The carotid artery is medial to(on the inside of) the jugular vein and is a good target. Honestly, if I were able and wanted to inflict maximum damage from a bladed attack to the neck I would insert by stabbing where I thought the jug/carotid were and direct the knife to the contralateral side and backwards. When withdrawing, I'd try to pull the whole thing over to the other side. Alternatively you could direct it to the other ear(the back of it.) If you make a muscle in your neck, you'll see your sternocleidomastoid muscle. There's an inverted V formed by this muscle as one head goes to the clavicle and the other goes to the sternum. the hollow at the top of this V is a pretty good shot on the carotid and jugular.

If you get stabbed or cut and the guy runs off(or if it's an accident, etc) the treatment is DIRECT PRESSURE. Avoid tourniquets. Don't use pressure points above the injury. Get some rags or whatnot and jam them right on the wound and push HARD. Virtually all extremity injuries and even most neck injuries can be controlled by this maneuver.

Bear in mind that a fatal wound won't necessarily equal stopping your opponent. It does you no good if you get killed and then your opponent dies later in the ED or in the ICU.

Hence my statement about head injuries."

Read the comment on this post as it is an excellent critique.