All posts by The Trauma Pro

Button Batteries: Part 1

I know what you are saying. Button batteries? Trauma? Not too many adult trauma professionals have seen or heard of this. But those who care for pediatric patients should be very familiar. If the importance of this seemingly minor problem is ignored, the results can be catastrophic.

Kids eat stuff, and not just food. The smaller ones always seem to be putting things in their mouths. Foreign body ingestion (or insertion into other orifices) is a common presentation at pediatric emergency departments. Unfortunately, the fact that a battery has been eaten may not be appreciated by the parents.  The child may be brought in with  nonspecific GI or respiratory symptoms.

As soon as a battery ingestion is known or suspected, a two-view chest x-ray is needed. This should show both chest and upper abdomen in order to visualize both esophagus and stomach. Separate chest and abdominal images may be required if the child is too large for a single shot. Two views (AP and lateral) are important because the nature of the foreign body may not be appreciated if the battery is seen edge-on.

If you are fortunate enough to image the battery “face-on”, you may see a telltale halo sign. Because of the way these batteries are put together, there are two metal sides that have a slight difference in overlap.

You’ve made the diagnosis! So now what? And how quickly? I’ll deal with this in my next post.

How Fast Can You Warm Up A Hypothermic Patient?

For most places, including Minnesota, hypothermia time is just about over! However, this trauma problem can occur nearly anywhere and at any time. And especially during a massive resuscitation. The optimal way to warm paitients has been debated for years. A number of very interesting techniques have been devised. Ever wonder how fast / effective they are?

I’ve culled data from a number of sources, and here is a summary what I found. And of course, the disclaimer: “your results may vary.”

Warming Technique Rate of Rewarming
Passive external (blankets, lights) 0.5° C / hr
Active external (lights, hot water bottle) 1 – 3° C / hr
Bair Hugger (a 3M product, made in Minnesota of course!) 2.4° C / hr
Hot inspired air in ET tube 1° C / hr
Fluid warmer 2 – 3° C / hr
GI tract irrigation (stomach or colon, 40° C fluid, instill for 10 minutes, then evacuate) 1.5 -3° C / hr
Peritoneal lavage (instill for 20-30 minutes) 1 – 3° C / hr
Thoracic lavage (2 chest tubes, continuous flow) 3° C / hr
Continuous veno-venous rewarming 3° C / hr
Continuous arterio-venous rewarming 4.5° C / hr
Mediastinal lavage (thoracotomy) 8° C / hr
Cardiopulmonary bypass 9° C / hr
Warm water immersion (Hubbard or therapy tank) 20° C / hr

In The Next Trauma MedEd Newsletter: Potpourri

The next issue of Trauma MedEd will be sent out to subscribers at the end of the week, and will cover a whole bunch of what I call Potpourri. These are some tidbits that I find fascinating and sometimes odd.

Topics will include:

  • Trauma and the gut microbiome
  • “Single look trauma laparotomy” (as opposed to damage control laparotomy) and postop complications
  • Pneumothorax: how big is too big?
  • The best prehospital stretchers for rapid extraction in MCIs
  • and more!

I’ve pushed the solid organ injury update issue out to next month. There’s a lot of stuff to cover, and quite a few changes have occurred over the years.

As always, this month’s issue will go to all of my subscribers first. If you are not yet one of them, click this link right away to sign up now and/or download back issues.

Unfortunately, non-subscribers will have to wait until I release the issue on this blog, in mid-April. So sign up now!

The Lead Gown Pull-Up: Part 2

Okay, so you’ve seen “other people” wearing perfectly good lead aprons lifting them up to their chin during portable x-rays in the trauma bay. Is that really necessary, or is it just an urban legend?

After hitting the medical radiation physics books (really light reading, I must say), I’ve finally got an answer. Let’s say that the xray is taken in the “usual fashion”:

  • Tube is approximately 5 feet above the xray plate
  • Typical chest settings of 85kVp, 2mAs, 3mm Al filtration
  • Xray plate is 35x43cm

The calculated exposure to the patient is 52 microGrays. Most of the radiation goes through the patient onto the plate. A very small amount reflects off their bones and the table itself. This is the scatter we worry about.

So let’s assume that the closest person to the patient is 3 feet away. Remember that radiation intensity diminishes as the square of the distance. So if the distance doubles, the intensity decreases to one fourth. By calculating the intensity of the small amount of scatter at 3 feet from the patient, we come up with a whopping 0.2 microGrays. Since most people are even further away, the dose is much, much less for them.

Let’s put it perspective now. The background radiation we are exposed to every day (from cosmic rays, brick buildings, etc) amounts to about 2400 microGrays per year. So 0.2 microGrays from chest x-ray scatter is less than the radiation we are exposed to naturally every hour!

The bottom line: unless you need to work out you shoulders and pecs, you probably don’t bother to lift your lead apron every time the portable x-ray unit beeps. It’s a waste of time and effort! Just stand back and enjoy!

The Lead Gown Pull-Up?

Trauma Team members typically wear a lead gown under their personal protective equipment so they don’t have to run out of the room when x-rays are taken. How often do you see people do this?

Is it really necessary? Or is it just a way to exercise your pecs and biceps? Tomorrow I’ll talk about how much radiation team members are really exposed to so you can decide if this is really necessary.