Tag Archives: stab wounds

To Probe or Not To Probe: Penetrating Wounds

There is considerable variability in the way that penetrating wounds are approached. Some are located over areas of lesser importance (distal extremities) or are so superficial that they obviously don’t fully penetrate the skin.

Unfortunately, some involve high-value structures (much of the neck and torso), or are too small to tell if they penetrate (ice pick injury). How should these injuries be approached?

Too often, someone just probes the wound and makes a pronouncement based on that assessment. Unfortunately, there are major problems with this technique:

  • The tract may be too small to appreciate with a finger or even a cotton-tip swab
  • The tract may be oriented in an unexpected direction, or the soft tissues may have moved after the penetration occurred. In this case, the examiner may not appreciate any significant depth to the wound.
  • Inserting an object may violate a structure that you wish it hadn’t (resulting in a hissing sound after probing a chest wound, or a column of blood after probing the neck)

A better way to approach these wounds is as follows:

  • Is the patient unstable? If so, you know the penetration caused the problem and the patient belongs in the OR.
  • Is there other evidence of deep injury, such as peritonitis with a penetrating abdominal wound? If so, the patient still needs to go to the OR.
  • Do a legitimate local wound exploration. This entails making the hole bigger with a knife, and using surgical instruments and your eyes to find the bottom of the tract. Obviously, there are some parts of the body where this cannot be done, such as the face, but they probably don’t need this kind of workup anyway.

As one of my mentors, John Weigelt, used to say, “Doctor, do you have an eye on the end of your finger?” In general, don’t use anything that doesn’t involve an eyeball in your local wound explorations!

How To Read A Stab Wound

Most emergency departments do not see much penetrating trauma. But it is helpful to be able to learn as much as possible from the appearance of these piercing injuries when you do see them. This post will describe the basics of reading stab wounds.

Important: This information will allow some basic interpretation of wounds. It will not qualify you as a forensics expert by any means. I do not recommend that you document any of this information in the medical record unless you have specific forensic training. You should only write things like “a wound was noted in the midepigastrium that is 2 cm in length.” Your note can and will be used in a court of law, and if you are wrong there can be significant consequences for the plaintiff or the defendant. This information is for your edification only.

1. What is the length of the wound? This does not necessarily correspond to the width of the blade. Skin stretches as it is cut, so the wound will usually retract to a length that is shorter than the full width of the blade.

2. Is the item sharp on one side or both? This can usually be determined by the appearance of the wound. A linear wound with two sharp ends is generally a two sided knife. A wound with one flat end and one sharp end is usually from a one-sided weapon. The picture below shows a knife wound with one sharp side.

3. Is there a hilt mark? This can usually be detected by looking for bruising around the wound. The picture below shows a knife wound with a hilt mark.

4. What is the angle? If both edges are symmetric, the knife went straight in. If one surface has a tangential appearance, then the knife was angled toward that side. You can approximate the direction of entry by looking at the tangential surface of the wound edge. In this example, the blade is angling upward toward the right.

5. How deep did it go? You have no way of knowing unless you have the blood stained blade in your possession. And yes, it is possible for the wound to go deeper than the length of the knife, since the abdominal wall or other soft tissues can be pushed inwards during the stab.

What Would You Do? Knife To The Back!

Here’s an interesting case to consider. A young male is assaulted and stabbed to the back. Paramedics bring him to your ED as a trauma team activation, and the full team is assembled prior to his arrival. 

He is brought into the room on the stretcher in the prone position. Here is a representative picture. This is not the actual patient, just a picture I found on another blog site that looks pretty close to the real case.

Let’s walk through the thought processes of managing this over the next few days.

First, what do you need to know right now to navigate your critical decision points? And what are you going to do regarding positioning, evaluation, and imaging?

Tweet or comment with your replies! More on Monday.

Best Of: How To Read A Stab Wound

Most emergency departments do not see much penetrating trauma. But it is helpful to be able to learn as much as possible from the appearance of these piercing injuries when you do see them. This post will describe the basics of reading stab wounds.

ImportantThis information will allow some basic interpretation of wounds. It will not qualify you as a forensics expert by any means. I do not recommend that you document any of this information in the medical record unless you have specific forensic training. You should only write things like “a wound was noted in the midepigastrium that is 2 cm in length.” Your note can and will be used in a court of law, and if you are wrong there can be significant consequences for the plaintiff or the defendant. This information is for your edification only.

1. What is the length of the wound? This does not necessarily correspond to the width of the blade. Skin stretches as it is cut, so the wound will usually retract to a length that is shorter than the full width of the blade.

2. Is the item sharp on one side or both? This can usually be determined by the appearance of the wound. A linear wound with two sharp ends is generally a two sided knife. A wound with one flat end and one sharp end is usually from a one-sided weapon. The picture below shows a knife wound with one sharp side.

Single edge knife wound

3. Is there a hilt mark? This can usually be detected by looking for bruising around the wound. The picture below shows a knife wound with a hilt mark.

Knife wound with hilt mark

4. What is the angle? If both edges are symmetric, the knife went straight in. If one surface has a tangential appearance, then the knife was angled toward that side. You can approximate the direction of entry by looking at the tangential surface of the wound edge. In this example, the blade is angling upward toward the right.

Angled knife entry

5. How deep did it go? You have no way of knowing unless you have the blood stained blade in your possession. And yes, it is possible for the wound to go deeper than the length of the knife, since the abdominal wall or other soft tissues can be pushed inwards during the stab.

Technique: How To Close A Full Thickness Stab (Abdomen) Laparoscopically

The algorithm for evaluating a stab to the anterior abdomen includes a number of different techniques for evaluation. In some cases where the chance of entry into the abdomen is thought to be low probability, endoscopic exploration can be used. What if a full thickness stab is detected, but the surgeon is able confirm that no abdominal injuries are present? Should the stab defect be closed?

There is no good data that tells us the incidence of ventral hernia from stab wounds. We do know that 10mm endoscopic port sites and larger can be the source of a ventral hernia and possible bowel obstruction after laparoscopic surgery, so it stands to reason (but be careful) that the same thing could happen with larger stabs. So why not close them?

A number of commercial devices have been developed for port site closure during endoscopic surgery (Carter Thomason Closure System, Cooper Surgical; Endo Close, Covidien). A group in Tokyo published a description of the technique using the former device to close the fascial defect of a self-inflicted stab wound.

Bottom line: This is an interesting use for a device used for closing more controlled stab wounds (surgical port sites) in less controlled ones. It seems fair to extrapolate our current experience from laparoscopic surgery to trauma in this case. I would be very interested to hear from anyone who is currently using this technique.

Reference: A quick and easy closure technique for abdominal stab wound after diagnostic laparoscopy. J Trauma 72(5):1448-1449, 2012.