Category Archives: General

Trauma In Pregnancy 2: Predicting Outcome

The data on maternal outcome after trauma is mixed and somewhat confusing. Mortality after major trauma actually appears to be less. However, injury severity score (ISS) still correlates fairly well with overall mortality. But interestingly, other outcomes (complications) appear to be worse, even for relatively minor injuries. The reason behind this is not clear. Could it be a result of all of the physiologic changes noted above, hormonal factors, or something we don’t fully understand?

Fetal outcome is a function of the mechanism of injury (blunt vs penetrating), and extreme injury severity in the mother. Penetrating injury is uniformly devastating to the fetus, with 70% mortality for gunshots and 40% for stabs. Fetal death from blunt injury is primarily a function of placental abruption. About two thirds of blunt fetal deaths are due to abruption, with 50% of them due to car crashes. Maternal ISS does not correlate with fetal death, except in cases of very high scores. These women most likely experience anatomic and physiologic injuries that lead to fetal demise.

Tomorrow: Tips & Tricks

Reference: Trauma during pregnancy. OB Clinics of North America 40:47-57, 2013.

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Trauma In Pregnancy 1: Introduction

Trauma in the pregnant patient is scary, but thankfully not very common. About 1 in 15 pregnant women sustain some type of significant injury. About half are from car crashes (most commonly if unrestrained), and 25% each are from assault (frequently domestic) and falls. Unfortunately, trauma is the leading cause of non-obstetric fetal death.

What makes this type of trauma problematic is two-fold, literally. First, you have two patients. And second, neither one has “normal” physiology. The mother has made numerous adaptations to accommodate the pregnancy, and the fetus is essentially a small parasite, totally dependent on her.

Let’s look at the impact of some of the more important maternal adaptations:

  • Total blood volume increases by about one liter. This would seem to be good, but since it is mainly dilutional with no real increase in total RBCs, and this is coupled with a lower mean blood pressure. Trauma professionals can easily underestimate blood loss.
  • Going into the third trimester, the uterus can compress the IVC when the mother is lying supine. but it is quite frequently forgotten. One of the first maneuvers when you suspect an advanced pregnancy is to bump the patient to her left. Do this even if the blood pressure is normal.
  • The pelvic veins are huge. Disruption from pelvic fractures or penetrating injury can lead to massive bleeding.
  • The stomach is probably full, and under pressure from below. This increases aspiration risk in women who have decreased mental status or need intubation.

And don’t forget the fetus:

  • The fetal/placental/uterine complex is one large, non-compressible unit with multiple shear planes within it. Blunt force will stress those planes, and may result in disruption of the uterus from pelvic veins (massive bleeding), or separation of the placenta from the uterus (abruption).
  • The fetus is totally dependent on the mother for survival, but the placenta will protect the mother first, shutting down fetal circulation if she becomes hypotensive or hypoxic.
  • The baby was designed to come into this world at full term. We have developed the technology to sustain life in smaller and more premature babies. The magic number of weeks keeps slowly decreasing, but preemie survival without complications is a challenge.

Tomorrow, we’ll move on and get to the fun stuff, predicting outcome after trauma in pregnancy.

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Does The Tertiary Survey Really Work?

Delayed diagnoses / missed injuries are with us to stay. The typical trauma activation is a fast-paced process, with lots of things going on at once. Trauma professionals are very good about doing a thorough exam and selecting pertinent diagnostic tests to seek out the obvious and not so obvious injuries.

But we will always miss a few. The incidence varies from 1% to about 40%, depending on who your read. Most of the time, they are subtle and have little clinical impact. But some are not so subtle, and some of the rare ones can be life-threatening.

The trauma tertiary survey has been around for at least 30 years, and is executed a little differently everywhere you go. But the concept is the same. Do another exam and check all the diagnostic tests after 24 to 48 hours to make sure you are not missing the obvious.

Does it actually work? There have been a few studies over the years that have tried to find the answer. A paper was published that used meta-analysis to figure this out. The authors defined two types of missed injury:

  • Type I – an injury that was missed during the initial evaluation but was detected by the tertiary survey.
  • Type II – an injury missed by both the initial exam and the tertiary survey

Here are the factoids:

  • Only 10 observational studies were identified, and only 3 were suitable for meta-analysis
  • The average Type I missed injury rate was 4.3%. The number tended to be lower in large studies and higher in small studies.
  • Only 1 study looked at the Type II missed injury rate – 1.5%
  • Three studies looked at the change in missed injury rates before and after implementation of a tertiary survey process. Type I increased from 3% to 7%, and Type II decreased from 2.4% to 1.5%, both highly significant.
  • 10% to 30% of missed injuries were significant enough to require operative management

Bottom line: In the complex dance of a trauma activation, injuries will be missed. The good news is that the tertiary survey does work at picking up many, but not all, of the “occult” injuries. And with proper attention to your patient, nearly all will be found by the time of discharge. Develop your process, adopt a form, and crush missed injuries!

Related posts:

Reference: The effect of tertiary surveys on missed injuries in trauma: a systematic review. Scand J Trauma Resusc Emerg Med 20:77, 2012.

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The Tertiary Survey for Trauma

Major trauma victims are evaluated by a team to rapidly identify life and limb threatening injuries. This is accomplished during the primary and secondary surveys done in the ED. The ATLS course states that it is more important for the team to identify that the patient has a problem (e.g. significant abdominal pain) than the exact diagnosis (spleen laceration). However, once the patient is ready for admission to the trauma center, it is desirable to know all the diagnoses.

This is harder than it sounds. Physical examination tends to direct diagnostic testing, and some patients may not be feeling pain, or be awake enough to complain of it. Injuries that are painful enough may distract the patient’s attention away from other significant injuries. Overall, somewhere between 7-13% of patients have injuries that are missed during the initial evaluation.

A well-designed tertiary survey helps identify these occult injuries before they are truly “missed.” This survey consists of a structured and comprehensive re-examination that takes place within 48-72 hours, and includes a review of every diagnostic study performed. Ideally, it should be carried out by two people: one familiar with the patient, and the other not. It is desirable that the examiners have some experience with trauma (sorry, medical students).

The patients at highest risk for a missed injury are those with severe injuries (ISS>15) and/or impaired mental status (GCS<15). These patients are more likely to be unable to participate in their exam, so a few injuries may still go undetected despite a good exam.

I recommend that any patient who triggers a trauma team activation should receive a tertiary survey. Those who have an ISS>15 should also undergo the survey. Good documentation is essential, so an easy to use form should be used. Click here to get a copy of our original paper form. We have changed over to an electronic record, and have created a dot phrase template, which you can download here.

Tomorrow: Does the tertiary survey actually work?

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Trauma Activation For Hanging: Yes or No?

In my last post, I discussed a little-reviewed topic, that of strangulation. I recommended activating your trauma team only for patients who met the physiologic criteria for it.

But now, what about hangings? There are basically two types. The judicial hanging is something most of you will never see. This is a precisely carried out technique for execution and involves falling a certain height while a professionally fashioned noose arrests the fall. This results in a fairly predictable set of cervical spine/cord, airway, and vascular injuries. Death is rapid.

Suicidal hangings are far different. They involve some type of ligature around the neck, but rarely and fall. This causes slow asphyxiation and death, sometimes. The literature dealing with near hangings is a potpourri of case reports, speculation, and very few actual studies. So once again, we are left with little guidance.

What type of workup should occur? Does the trauma team need to be called? A very busy Level I trauma center reviewed their registry for adult near-hangings over a 19 year period. Hanging was strictly defined as a ligature around the neck with only the body weight for suspension. A total of 125 patients were analyzed, and were grouped into patients presenting with a normal GCS (15), and those who were abnormal (<15).

Here are the factoids:

  • Two thirds of patients presented with normal GCS, and one third were impaired
  • Most occurred at home (64%), and jail hangings occurred in 6%
  • Only 13% actually fell some distance before the ligature tightened
  • If there was no fall, 32% had full weight on the ligature, 28% had no weight on it,  and 40% had partial weight
  • Patients with decreased GCS tended to have full weight on suspension (76%), were much more likely to be intubated prior to arrival (83% vs 0% for GCS 15), had loss of consciousness (77% vs 35%) and had dysphonia and/or dysphagia (30% vs 8%)
  • Other than a ligature mark, physical findings were rare, especially in the normal GCS group. Subq air was found in only 12% and stridor in 18%.
  • No patients had physical findings associated with vascular injury (thrill, bruit)
  • Injuries were only found in 4 patients: 1 cervical spine fracture, 2 vascular injuries, and 1 pneumothorax
  • 10 patients died and 8 suffered permanent disability, all in the low GCS group

Bottom line: It is obvious that patients with normal GCS after attempted hanging are very different from those who are impaired. The authors developed an algorithm based on the initial GCS, which I agree with. Here is what I recommend:

  • Do not activate the trauma team, even for low GCS. This mechanism seldom produces injuries that require any surgical specialist. This is an exception to the usual GCS criterion.
  • The emergency physician should direct the initial diagnosis and management. This includes airway, selection of imaging, and directing disposition. A good physical exam, including auscultation (remember that?) is essential.
  • Patients with normal GCS and minimal neck tenderness or other symptoms do not need imaging of any kind.
  • Patients with abnormal GCS should undergo CT scanning, consisting of a CT angiogram of the neck and brain with soft tissue images of the neck and cervical spine recons.
  • Based on final diagnoses, the patient can be admitted to an appropriate medical service or mental health. In the very rare case of a spine, airway, or vascular injury, the appropriate service can be consulted.

Reference: A case for less workup in near hanging. J Trauma 81(5):925-930, 2016.

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