All posts by TheTraumaPro

When Can You Close That Stab Wound?

I find that many trauma professionals are nervous about closing stab wounds. They seem to worry a lot about infections and lean toward leaving the wound open to heal by secondary intention. But is this warranted?

The answer is: probably not. Most knives used for assaults are clean, but not quite sterile. Yes, there are a few bacteria on the blade, but not very many. So if the usual wound management guidelines are followed, the patients generally do quite well. 

The guidelines are:

  • No gross contamination. If the knife was used to cut raw chicken or to stir up manure, that’s a problem. Leave it open.
  • No devitalized tissue. Complex lacerations with dusky skin bridges may get infected. Debride or leave open.
  • Don’t let the wound get fully colonized with skin bacteria. There is no good literature on this, but more than 12 hours for most of the body and 24 hours for the face is a reasonable guideline.

If any of these guidelines have been violated, it’s probably best to leave the wound open. Otherwise the default should be to try to close it as soon and as cleanly as possible. This means irrigating with saline to decrease any bacterial counts. Either sutures or staples are acceptable.

The most important part of this process is patient education. They must be informed about what signs of a wound infection to look for so they can return earlier rather than later to have you deal with it.

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Practical Tips On Diaphragm Injury

Diaphragm injuries are notoriously hard to detect, and there is a significant rate of delayed or missed diagnosis. Today I’ll offer a few practical tips on finding and managing this rare injury.

Mechanism is important. Penetrating injury is more common, and it can be really tough to diagnose this injury in stabs to the lower chest. Anything below the nipples is suspect. Blunt injury requires substantial force. This is seen in deceleration injuries, usually with a crush component to the abdomen. Ejection and partial ejection is common.

Left sided injury is much more common than right. The liver probably diffuses the force more evenly, protecting the right diaphragm. Be very skeptical if a radiologist tries to tell you the patient has a right diaphragm injury.

Patients have significant symptoms with blunt injury. Respiratory distress is common on the left, and deep visceral pain on the right if the liver partially herniates into the chest. Serious associated injuries are common due to the high energy involved.

Diagnosis is difficult. CT is a very good, but imperfect, tool. Coronal and sagittal reconstructions can be very helpful.

If you are inclined to explore for a possible diaphragm injury in a stable patient, consider laparoscopy first. But warn the anesthesiologist! If your patient has the injury, they will rapidly develop a complete pneumothorax, so you need to be ready to quickly insert a chest tube.

Caress the diaphragm to find small holes. Place your hand in the palm up position so your fingers will drop into any defect. Be thorough, since small knife and bullet wounds are easy to miss, especially when located posteriorly.

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Removing The Backboard II

Ten months ago I wrote about getting patients off backboards as soon as possible. The question has arisen again, so I did a little digging to find some good science behind this. And I found it.

This problem has been looked at three ways. From best to worst they are: studies on OR patients who developed pressure ulcers postop, studies on animals, and studies on tissues. I’ll focus on the first because a real person who is chemically and physically restrained to an OR table is very similar to one who has been fastened to a backboard.

The most cited study (retrospective, of course) showed that patients who had tissue pressure over bony prominences that exceeded their diastolic pressure developed pressure ulcers within 6 hours, and even faster with higher tissue pressures. But even better prospective OR studies have been done, and these showed that ulcers could occur in as little as three hours.

Keep in mind that these studies involved patients in whom real efforts were made to pad bony prominences and actively avoid tissue injuries. Yet they still occurred. Contrast this with a patient who is strapped to a hard backboard in your ED, with little ability to adjust their position to improve circulation.

Related work has shown that:

  • Tissue injury is more likely in the elderly, probably because they have less adipose padding
  • Obesity is not protective! The increased weight increases tissue pressure out of proportion to the padding effect
  • A harder surface shortens the time to tissue damage
  • Hypotension is bad, both for the patient’s well-being and for the skin over their bony prominences

Bottom line: Get your patients off that backboard ASAP! I recommend sliding it out when they are logrolled to examine the back. The board is of little or no benefit to spine stability in a cooperative patient. And we have ways of encouraging cooperation if they are not.

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Reference: How Much Time Does it Take to Get a Pressure Ulcer? Integrated Evidence from Human, Animal, and In Vitro Studies. Ostomy Wound Management. 54(10):26-8, 30-5, 2008.

What’s The Diagnosis #1?

Okay, time for the answer. This 12 year old crashed his moped, taking handlebar to the mid-epigastrium. Over the next 3 days, he felt progressively worse and finally couldn’t keep food down.

Mom brought him to the ED. The child appeared ill, and had a WBC count of 18,000. The abdomen was firm, with involuntary guarding throughout and a hint of peritonitis. The diagnosis was made on the single abdominal xray shown yesterday. A closeup of the good stuff is above.

Emergency docs, your differential diagnosis list with this history is a pancreatic vs a duodenal injury based on the mechanism.

Classic findings for duodenal injury:

  • Scoliosis with the concavity to the right. This is caused by psoas muscle irritation and spasm from retroperitoneal soiling by the duodenal leak.
  • Loss of the psoas shadow on the right. Hard to see on this xray, but the left psoas shadow is visible, the right is not. This is due to fluid and inflammation along this plane.
  • Air in the retroperitoneum. In this closeup, you can actually see tiny bubbles of leaked air outlining the right kidney. There are also bubbles along the duodenum and a few along the right psoas.

We fluid resuscitated first (important! dehydration is common and can lead to hemodynamic issues upon induction of anesthesia) and performed a laparotomy. There was a  blowout in the classic position, at the junction of 1st and 2nd portions of the duodenum. The hole was repaired in layers and a pyloric exclusion was performed, with 2 closed drains placed in the area of the leak.

The child did well, and went home after 5 days with the drains out. Feel free to common or leave questions!

To see the full-size abdominal xray, click here.