All posts by The Trauma Pro

How To: Manage Rectus Sheath Hematomas

June 4, 2019 The Trauma Pro Leave a comment

Although not strictly traumatic, rectus sheath hematomas frequently come to the attention of trauma professionals. In some cases, they may be due to vigorous physical activity or blunt impact. They may also occur spontaneously, especially in patients who are anticoagulated.

This is not a very common condition, accounting for only 1-2% of patients who present with acute abdominal pain. The common etiology of rectus hematomas is either a tear of the major blood supply (superior and inferior epigastric arteries) or a tear of the muscle itself with bleeding from smaller vessels. The loose attachment of the inferior epigastric and the fixed perforating muscular branches make injury in the lower half of the muscle more common.

These hematomas are frequently self-limiting problems. The rectus sheath provides containment for the hematoma, and as pressure rises, bleeding slows and stops. However, if the hematoma is able to escape posteriorly, it can result in life-threatening bleeding.

Presentation generally consists of abrupt onset of focal abdominal pain, and an abdominal wall mass. The pain can be rather intense, making it difficult to determine if it is intraperitoneal or in the body wall. Tip: ask the patient to tense their abdominal wall muscles, then palpate the area. If the tenderness increases, then it is more likely due to an abdominal wall source. Tensing the muscles will shield sources inside the peritoneal cavity, decreasing tenderness to palpation.

Diagnosis may be made by physical exam, but not always. The hematoma may be seen using ultrasound, but the gold standard is the contrast-enhanced CT. Contrast is essential to determine if active extravasation is occurring.

Ultrasound

CT scan with contrast showing extravasation

Patients who are hemodynamically stable and do not have active extravasation may be treated conservatively. However, a significant number of patients will require at least one unit of blood. Be prepared and send a type and crossmatch. Conservative management includes ice packs for pain relief, direct pressure (sand bags), and reversal of anticoagulation if possible. Stable patients with extravasation on CT should be evaluated by angiography and embolized if a bleeding vessel can be identified.

Unstable patients must be resuscitated promptly with fluid and blood so they can be taken to the angiography suite. Operative exploration is extremely unsatisfying and should be avoided, since it is difficult to find the bleeding vessels in the midst of a huge hematoma.

Imaging

Management Of Penetrating Neck Trauma: The Future?

June 3, 2019 The Trauma Pro Leave a comment

In my last post, I described the evolution of the classic approach to penetrating neck injury. Today, I’ll propose a new way of managing it based on a combination of physical exam and CT scan.

This proposal is based on the high degree of accuracy that CT angiography of the neck provides. It is very sensitive for identifying even small injuries to the aerodigestive tract and vascular system. This study is based on work done at LA County – USC Hospital several years ago.

The trauma group at LAC+USC organized a prospective, multicenter study using a multidetector CT angiography of the neck for initial screening of penetrating neck injury. This allows evaluation the neck as a single unit, not as three zones. It also solves the problem of trying to apply zones to injuries that cross several of them.

The new algorithm that was tested utilized an initial physical exam, first looking specifically for “hard signs” of injury. The following were considered the hard signs:

Active hemorrhage
Expanding or pulsatile hematoma
Bruit or thrill over the injured area
Unresponsive shock
Hemoptysis or hematemesis
Air bubbling from the wound

These patients were immediately taken to the OR and explored through an appropriate incision.

Patients with no signs or symptoms were admitted and observed for at least 24 hours. All other patients were considered to have “soft signs.” They underwent multidetector CT angiography of the neck, with a scanner having at least 40 slices. Further evaluation of these patients was based on the exam and CT scan.

Here are the factoids:

453 patients with penetrating neck injury were identified during the 31 month study period
9% had hard signs and were taken to OR; 50% had soft signs are underwent CT; 41% had no signs and were observed
For soft sign patients, 86% of scans were negative and all were true negatives after observation
12% of soft sign patients had a positive scan, and of those 81% were true positives
4 patients (2%) with soft signs had too much artifact for an accurate CT and other tests were performed; 1 of the 4 had an injury
Sensitivity of CTA was 100% and specificity was 97.5% in the soft sign patients
The authors concluded that CTA is very reliable for identifying injuries in patient with soft signs, and that patients with no signs do not require scanning, only observation

Bottom line: This is an intriguing paper that takes advantage of both physical examination at CT angiography. The results are impressive, but the numbers are still relatively small. It lends support to the argument that CTA is not required in all stable patients. But I can’t recommend completely changing our practice yet based on this one study. Additional numbers are certainly needed, but I suspect that this will become the norm in the future. I would also recommend that we all carefully look at our diagnostic algorithms to see other areas where we might identify and eliminate unneeded imaging, labs, etc.

Reference: Evaluation of multidetector computed tomography for
penetrating neck injury: A prospective multicenter study. J Trauma 72(3):576-584, 2012.

Tips

Management Of Penetrating Neck Trauma: The Way We Were/Are

May 30, 2019 The Trauma Pro Leave a comment

The management of penetrating injuries to the neck has changed very little over the years. Could it be time? Today, I’ll review some of the basics of classic diagnosis and treatment. In my next post, I’ll discuss an alternative way to approach it.

First, lets look at the time-honored zones of the neck. Here’s a nice diagram from EMDocs.net:

The zones are numbered in reverse, from bottom to top, and in Roman numerals.

The area below the cricoid cartilage is considered Zone I and contains many large vascular and aerodigestive structures that are relatively difficult to approach surgically. For this reason, diagnostic testing is recommended to assist in determining if an operation is actually needed and what the best surgical exposure would be. Obviously, this can only be considered in the stable patient. Unstable patients must go straight to the OR and the trauma surgeon will determine the surgical approach on the fly.

Similarly, the area above the angle of the mandible is Zone III, and is also difficult to expose. Injuries to this area may involve the distal carotid and vertebral arteries near the base of the skull, as well as the distal jugular vein. Surgical approach may require dislocation of or fracturing the mandible to get at this area. This is challenging and not that desirable, and few surgeons are familiar with the technique. For this reason, imaging is very desirable and often demonstrates that no significant injury is present. And endovascular / angiographic techniques are now available that may obviate the need for surgery.

Zone II is everything in-between the mandibular angle and cricoid cartilage. This is the surgical Easy Button. Exposure is simple and the operation is fun. In the old days, an injury to this area went straight to the OR regardless of whether there were signs or symptoms of injury. Yes, there were quite a few negative explorations. But we’ve become more selective now with the advent of improved resolution of our CT scans.

Currently, we usually follow a two-step approach to penetrating neck trauma:

Are there hard signs of injury present? These tell us that a structure that absolutely needs to be fixed has been injured. The patient should be taken directly to OR after control of the airway, if appropriate. Typical hard signs are:
1. Airway compromise
2. Active air bubbling from wound
3. Expanding or pulsatile hematoma
4. Active bleeding
5. Hematemesis
What zone is the injury in? And don’t just look at the obvious entry point. Gunshots (and long knives) may enter multiple zones. The zone then determines what happens next:
1. Zone I – CT angio of neck and chest. If positive, proceed to OR for repairs, and perform EGD and/or bronchoscopy as needed
2. Zone II – Old days: proceed to operating room for exploration, or angiogram, EGD, direct laryngoscopy, and bronchoscopy. Most chief residents chose the former. Current day: CTA of neck, followed by OR, EGD, bronchoscopy only if indicated.
3. Zone III – CT angio of the neck. If positive, consider angiography/endovascular consultation vs operation.

Changes from old days to more current thinking have been made possible by improvements in speed and resolution of our CT scanners. But why can’t we take this another step forward and streamline this process even more? I’ll propose some changes in my next post!

Reference: Western Trauma Association Critical Decisions in Trauma:
Penetrating neck trauma. J Trauma 75(6):936-940, 2013.

Education

You’ve Been Pimped! Origins And How To Survive It!

May 29, 2019 The Trauma Pro Leave a comment

What exactly is pimping? If you have ever been a medical student or resident in any discipline, you probably already know. It’s ostensibly a form of Socratic teaching in which an attending physician poses a (more or less) poignant question to one or more learners. The learners are then queried (often in order of their status on the seniority “totem pole”) until someone finally gets the answer. But typically, it doesn’t stop there. Frequently, the questioning progresses to the point that only the attending knows the answer.

So how did this time honored tradition in medical education come about? The first reference in the literature attributes it to none other than William Harvey, who first described the circulatory system in detail. He was disappointed with his students’ apparent lack of interest in learning about his area of expertise. He was quoted as saying “they know nothing of Natural Philosophy, these pin-heads. Drunkards, sloths, their bellies filled with Mead and Ale. O that I might see them pimped!”

Other famous physicians participated in this as well. Robert Koch, the founder of modern bacteriology, actually recorded a series of “pümpfrage” or “pimp questions” that he used on rounds. And in 1916, a visitor at Johns Hopkins noted that he “rounded with Osler today. Riddles house officers with questions. Like a Gatling gun. Welch says students call it ‘pimping.’ Delightful.”

So it’s been around a long time. And yes, it has some problems. It promotes hierarchy, because the attending almost always starts questions at the bottom of the food chain. So the trainees come to know their standing in the eyes of the attending. And they also can appreciate where their fund of (useful?) knowledge compares to their “peers.” It demands quick thinking, and can certainly create stress. And a survey published last year showed that 50% of respondents were publicly embarrassed during their clinical rotations. What portion of this might have been due to pimping was not clear.

Does pimping work? Only a few small studies have been done. Most medical students have been involved with and embarrassed by it. But they also responded that they appreciated it as a way to learn. A 2011 study compared pimping (Socratic) methods to slide presentations in radiology education. Interestingly, 93% preferred pimping, stating that they felt their knowledge base improved more when they were actively questioned, regardless of whether they knew the answer.

So here are a few guidelines that will help make this technique a positive experience for all:

For the “pimpers”:

Make sure that the difficulty level of questions is reasonable. You are testing your learners’ knowledge, not spotlighting your own mental encyclopedia
Build the level of difficulty from questions that most can answer to one or two that no one knows, then switch to didactice teaching of the esoterica
Don’t let one learner dominate the answers; gently exclude them and solicit answers from others so they get a chance to participate
Provide positive reinforcement for correct answers, but don’t resort to negative reinforcement (insults) when they are wrong
Go Socratic when the answer is not known. Step back and review the basic concepts involved that helps your learners arrive at the correct answer.

For the “pimpees”:

Read, read, read! You are in this to learn, so study all the clinical material around you.
Talk to your seniors to find out your attending’s areas of interest. There’s a lot of stuff to learn, and this may help you focus your rounding preparation a bit. It still doesn’t absolve you from learning about all the other stuff, though.
Don’t be “that guy (or gal)” who tries to dominate and answer every question
If all else fails, and it’s one of those “percentage” questions, use my
“85/15 rule.” If the issue you are being asked about seems pretty likely, answer “85%.” If it seems unlikely, go with “15%.” It’s usually close enough to the real answer to satisfy.

Bottom line: Pimping is a time-honored tradition in medicine, but should not be considered a rite of passage. There is a real difference in attitudes and learning if carried out properly. Even attendings have a thing or two to learn about this!

Reference: The art of pimping. JAMA. 262(1):89-90, 1989.

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