Tag Archives: penetrating injury

The Evolution Of Penetrating Neck Trauma Management – Part 2: Initial Steps

In my previous post, I described the early days of penetrating neck injury management and introduced a paper suggesting that this concept should be revised. Today, I will summarize a paper by Siletz and Inaba that is currently in press and outlines what the contemporary way of treating these injuries should be.

Step 1. If present, rapidly control external hemorrhage and airway compromise. As always, bleeding should be controlled by direct pressure or packing. Direct pressure does not look like this:

The goal is to create a zone of pressure higher than the systolic BP perfectly in the area of bleeding. Since pressure is force per unit area, a larger area like that show above diffuses the maximum pressure and just doesn’t work. Note the ongoing bleeding shown in the picture.

Here’s what direct pressure looks like:

Or

A single finger (or maybe two) should be placed on or in the wound. If deeper bleeding is a problem, the same kind of pressure can be accomplished by packing with gauze. If gauze is used, however, pressure must usually be applied over the gauze to make sure that the underlying tissues remain pressurized.

If gauze packing is not practical because of this need for additional pressure, a urinary catheter can be inserted into the wound and inflated until the bleeding stops.

Courtesy Core EM

Airway control should ideally occur in the operating room. Given the proximity of this wound to airway structures, it is imperative that an ideal environment is present when the airway is inserted. A skilled anesthesiologist should be present, with difficult airway equipment available if needed. The surgeon should be standing by with all equipment needed to obtain a surgical airway if needed. Even though the patient may be breathing okay, the airway structures may be distorted by hematoma or injury.

You have probably noted that this is the same initial assessment we used in the old three zones approach. In the next post, I will discuss the details of a new assessment approach that considers the neck a single unit.

 

The Evolution Of Penetrating Neck Trauma Management – Part 1

“When the facts change, I change my mind. What do you do, sir?”

This is a famous quote from John Maynard Keynes. (Or is it? There is some debate over its authenticity, but you get the idea it tries to convey.) Our knowledge base continually changes, so we must be willing to change our minds (and practices) based on new, reliable information.

The management of penetrating neck injury is one of those facets in trauma care that has undergone slow but steady progress over the past 40 years of my career. In the old days, we quickly identified the zone of injury and proceeded to the operating room for Zone II injuries. We had to think a little harder about the other zones to be certain that we needed to be in the OR. But overall, the threshold for surgery was low.

Things have been changing. Five years ago, I published a post detailing new work by Inaba et al. at LAC+USC. This started a move toward using more straightforward criteria and advanced imaging to assist decision-making with these injuries.

In this post, I’ll summarize the original paper. In the next section, I will describe the group’s paper, which is currently in press and outlines the full framework for workup or penetrating neck injury.

The advance that makes this new method possible is based on the high degree of accuracy that CT angiography of the neck provides. It is very sensitive for identifying even minor injuries to the aerodigestive tract and vascular system.

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 the evaluation of 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 injuries were identified during the 31-month study period
  • 9% had hard signs and were taken to the OR; 50% had soft signs and 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
  • four 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 patients with soft signs and that patients with no signs do not require scanning, only observation

Bottom line: This was an intriguing paper that utilized both physical examination and CT angiography. The results were impressive, and they supported the argument that CTA is not required in all stable patients. With additional numbers and time, it has become clear that we can safely adopt this algorithm. My next post will flesh out the details.

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

Use Of Radio-opaque Markers In Penetrating Trauma

As I was browsing through my journal list this week, I ran into an interesting title for an article that is currently in press.

“The use of radio-opaque markers is medical dogma”

Catchy, especially since I love writing about dogma vs what is really supported by the literature. The author questions the justification of this practice and posits that there are risks to extrapolating information based on radiographs with markers placed by the trauma team.

OLYMPUS DIGITAL CAMERA

The author first reviewed the literature on the use of markers for penetrating injury, which started only recently, in 2002. Markers were initially used to precisely locate the penetration site since skin wounds (obviously) don’t show up on X-rays. Typically, these were just plain old paper clips. Some trauma professionals placed them directly over the wound. Others un-bent them and fashioned them into shapes that pointed to the exact location of the wound.

With the growing usage of CT scans to evaluate stable patients, modifications to the marker were made. Small arrow markers designed for use on x-rays were frequently used. However, even the very small ones could cause enough scatter on a CT scan to interfere with diagnosis. At some centers, Vitamin E capsules were taped on top of the wound. But thankfully, there are now special markers that can pinpoint the wound without degrading the tomographic image.

The author goes on to describe how gunshot wounds specifically are difficult to assess with a marker. Although the exact surface location may be noted, the underlying injuries vary due to size, distance, velocity, and trajectory change from tissue density or bone strikes. He also notes that it may not be wise to place a marker into a bloody field in a potentially combative patients.

The article concludes that the use of this technique for identifying anything other than surface location of penetrations lacks clinical evidence and is based only on expert opinion. Which essentially makes it dogma.

Bottom line: Here are my thoughts. First, the use of markers on penetrating wounds has been going on for much longer than the 20 years found in the trauma literature reviewed here. It has been a common practice among trauma surgeons for many, many decades. Most “seasoned” (old) trauma surgeons have been doing and teaching this for their entire careers. 

I concur that we have techniques like CT scan available to us now that provide an excellent view of the penetration trajectory. The skin wound is usually apparent on the scan, but may be improved with the use of a CT-approved marker.

So why still do this for the patient arriving in your trauma bay? An experienced trauma surgeon can get a good sense of the trajectory based on the entry point, the exit wound, and the location of any retained bullet or fragments. Rapid placement of some kind of marker on all wounds followed by a quick image allows them to roughly predict what was hit, and assess the possibility that there might be bleeding that would drive the team straight to the operating room. It can help direct the surgical exploration if imaging was unnecessary or contraindicated. 

So yes, this is dogma. The reality is that no one will ever be able to design a study that definitively evaluates the very soft outcomes that result from using this technique. But every senior trauma surgeon can easily cite numerous examples in their career when this method has been extremely useful. The lack of a study only means that there will never be any evidence-based guideline for the use of this technique. However, it is still acceptable to have a protocol based on substantial clinical experience. But as with all dogma, once that definitive study finally does comes along, the protocol must be modified to adhere to the findings of the study.

For now, keep using those markers! And I’m very interested in comments from both old and young trauma professionals on this topic.

Reference: The Use of Radio-opaque Markers is Medical Dogma, doi:10.1111/acem.1485, Dec 2023.

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

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:

  1. 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
  2. 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.

Scoop And Run VS Stay And Play: Part 5

This is the last piece in my series on whether or not trauma patients should be initially managed with some limited interventions at the scene, vs just getting them into the ambulance and on their way to a trauma center. This article deals specifically with the needs of victims of penetrating trauma in big cities.

The Eastern Association for the Surgery of Trauma (EAST) published the results of a multicenter trial on the utility of prehospital procedures performed by EMTs and medics in this subset of patients. Most of the studies previously reviewed do not show an obvious advantage to dawdling at the scene.

The EAST study took an interesting approach. It limited patients to those in urban locations near trauma centers, which largely eliminated time from the equation. The authors could then attempt to identify any utility in performing procedures prior to trauma center arrival.

This was an observational trial of adults with penetrating injury to the torso or proximal extremity. A total of 25 trauma centers participated for a one-year period. Patients with penetrating injuries above the clavicles or in the distal extremities were excluded.

Here are the factoids:

  • Although 2,352 patients met inclusion criteria, a small number (68) were excluded because the method of transport was missing (!)
  • Type of transport was ALS (63%), private vehicle (17%), police (14%), and BLS (7%)
  • Nearly two-thirds (61%) received some type of prehospital procedure
  • The procedures performed included intubation (6% on scene, 2% in transport), IV access (49% on scene, 42% in transport), IO access (5% on scene, 3% in transport), fluid resuscitation (16% on scene, 32% in transport),application of a pressure dressing (23% on scene, 12% in transport), and tourniquet application (6% on scene, 2% in transport)
  • Patients who received prehospital interventions had significantly longer hospital length of stay (5.6 vs 4 days) and were more likely to develop ARDS, venous thromboembolisms, and urinary tract infections
  • In-hospital mortality was significantly higher in the intervention group (10.3% vs 7.8%)
  • Mortality significantly increased with the number of interventions performed at the scene and enroute to the trauma center
  • Prehospital intubation was strongly correlated with mortality, and the following procedures were also associated with higher mortality: fluid resuscitation, cervical spine immobilization, and pleural decompression
  • Prehospital IV insertion was significantly associated with survival, but tourniquet placement was neutral
  • There was no mortality difference based on the type of transport provided

Bottom line: This is a fascinating paper that applies to a limited subset of patients. Specifically, it only studied patients in urban areas with a trauma center that was presumably very close. Prehospital endotracheal intubation proved to be the most deadly intervention. A few studies have confirmed that intubation further degrades end-organ perfusion further in animals with severe hemorrhagic shock.

The finding that prehospital fluids were associated with higher mortality, but that IV access was not, is puzzling at first. However, there are a number of papers clearly showing that resuscitation without definitive hemorrhage control, can be deadly. This study confirms this fact in humans and lends support to the concept of permissive hypotension in these patients. 

Cervical spine immobilization proved to be a mortality risk. The reasons are not clear, but difficulties in placing an airway and increased intracranial pressure could be factors. The only clear indication would be for stabilization of the neck in patients with cervical cord injuries. However, in such cases the damage is done and collars are likely not of any benefit neurologically.

The biggest flaw in this study was that it did not record transport times. The authors assumed that times were short since the patients were injured in high density urban areas. There was also concern for selection bias, as more severely injured patients were more likely to undergo prehospital intervention.

The takeaway message is that in a setting with very short transport time to a trauma center, hemorrhage control trumps almost everything else. Obtaining IV access or applying a tourniquet may be beneficial, but should only occur once the patient is enroute to minimize time on scene. More advanced maneuvers such as fluid resuscitation, fluid resuscitation, collar placement, or needle decompression of the chest should be delayed for management by the trauma team.

These results cannot be generalized to patients with longer expected transport times, although we don’t have good research yet to back up this assertion. In those patients, it is probably best to adhere to the good old ABCs of ATLS. And of course, until this work is confirmed by more studies, do not go against any policies or procedures established by your prehospital agency!

Reference: An Eastern Association for the Surgery of Trauma multicenter trial examining prehospital procedures in penetrating trauma patients. J Trauma 91(1):130-140, 2021.