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.

So You Want Your Own Hybrid Room?!

You’re hooked! You are thinking back to a number of cases that you think might have done better with a hybrid room. And now let’s assume you already have one in your OR suite. Now what do you do?

The key is to avoid jumping right in and sending your next eligible patient straight to that room. You absolutely must take some time to develop policies and guidelines to make sure things go smoothly.

Here are some important things to think about:

  • Identify which specific patients are eligible so you don’t squander this resource
  • Who calls the OR to secure the room (surgeon, resident, other)?
  • Who calls the interventional radiologist?
  • What if another case (TEVAR, etc) is already on the table?
  • What if another case is getting ready to use the OR? How are conflicts resolved?
  • Develop an initial in-room report process so all the teams know the game plan
  • Assign an extra circulator to the room. You’ll need them!
  • Make sure all retractor systems (abdomen, head) fit the table! Remember that little asterisk in the previous section? Some retraction systems may need adaptors to work with your table. Don’t find this out at the last minute!
  • What about lithotomy position? How will this work with your hybrid table? They don’t have sections that break away.
  • Ensure radiation protection for all, including thyroid shields.
  • Bag the bottom x-ray detector, otherwise it will get very, very gross!
  • Create an external fixator equipment cart that can be moved into the hybrid room.
  • Create an embolization cart with appropriate wires, catheters, coils, etc. This stuff may not be stocked normally in the hybrid room

And I’m sure there are more details that I haven’t thought of. If you have some helpful suggestions, policies, or protocols, please share them with me!

Which Patients May Benefit From A Hybrid OR?

The key to answering this question is to look at the resources that a hybrid OR brings to bear, and then determine what types of patients can take full advantage of them. Sadly, we have no guidance from the trauma literature, so we need to let our imaginations run free.

The basic concept for hybrid room use is this:

“My patient needs interventional radiology plus at least one other surgical specialty procedure”

The additional procedures don’t necessarily need to benefit from or utilize the IR capabilities. But they do need to be of an emergent nature. For example, a patient with a pelvic fracture can undergo angio-embolization and pelvic external fixation, while the gynecologic surgeons repair a vaginal laceration. Simultaneous, but not related to the embolization.

Here’s my list of possibilities. It is by no means complete or exhaustive. It’s just a start. All include the interventional radiologist for some part of it:

  • Pelvic fractures with angioembolization plus:
    • Preperitoneal packing
    • Perineal / gynecologic repair
    • Laparotomy
  • Liver angioembolization plus laparotomy
  • Thoracic aortic injury plus laparotomy
  • Angiographic assistance for management of vascular extremity injury
  • Any of the previous procedures plus craniotomy*
  • And don’t forget to toss REBOA in with this!
  • Plus some other stuff I’m sure you will think up

Tomorrow, some details to think about while setting up your own hybrid OR!

Is The Hybrid OR For Trauma Useful?

Gee, the hybrid OR sounds like a great idea for specific trauma patients. But we’ve seen this before; great idea but doesn’t always translate into a positive result. Is there any literature?

Unfortunately, very little. A group from the University of Calgary in Alberta published a very detailed paper on the nuts and bolts of how they designed their hybrid room from scratch. This paper is very detailed, and the hospital personnel were very thoughtful as they approached the time-consuming and expensive task of designing and building their hybrid room. Of course, they chose a silly acronym as so many do. They called it their RAPTOR room (Resuscitation with Angiography, Percutaneous Treatments, and Operative Resuscitations). Sigh!

Next, they retrospectively analyzed their experience with persistently hypotensive patients arriving at their Level I trauma center over a 17-year period before their hybrid room opened.

Here are the factoids:

  • Of 911 patients, 510 remained persistently hypotensive (SBP<90 torr)
  • 53% (270 patients) were taken directly to OR, usually for laparotomy, thoracotomy, or vascular procedure
  • 29% were admitted to an ICU, 13% to a ward bed, and 5% were taken to interventional radiology (IR)
  • 35 patients (7%) required both OR and IR; the majority had pelvic fractures (77%), the rest had liver lacerations
  • Each case was reviewed, and overall 6% of patients would have clearly benefited from a hybrid room, and 30% would have potentially benefited

Sounds good so far! But we need some more data. Unfortunately, there’s not a lot of it yet. A Japanese group described their experience with treating patients in OR then IR, vs a “hybrid procedure.” This did not involve the use of a true hybrid OR. They moved a C-arm fluoroscopy unit into an OR and part of the procedure was carried out by an interventional radiologist.

And the factoids:

  • A total of 13 “hybrid treatment” patients were compared to 45 who underwent both operation and angiography, but not in the same location
  • Most of the hybrid patients had a laparotomy, but there was a concomitant thoracotomy in one and a craniotomy in another
  • The actual survival in the hybrid patients was 85%, while TRISS predicted that only 62% would live
  • There was no difference in transfusion volumes between the two groups, but total procedure time was significantly shorter in the hybrid group (4 hours vs 6 hours)

Okay, sounds promising. A second Japanese paper was published last year with much larger numbers. Their hybrid OR was actually a hybrid ER! They installed a multi-slice interventional radiology/CT unit in their resuscitation room! Here are the key findings:

  • A total of 696 patients were reviewed over an 8-year period – 336 hybrid and 360 conventional
  • Mortality was very significantly decreased in the hybrid group
  • OR start was significantly shortened from 68 minutes to 47

Here’s an image of their setup:

Key: A – mobile CT scanner, B – CT / OR table, C – mobile C-arm, D – 56” monitor, E – ultrasound, F- ventilator

Bottom line: This is quite a unique room. Unfortunately, it is not ideal because it is small and cramped. It looks like it would be difficult to fit more than one surgical team in the room. However, the results look good.

We are finally starting to see objective data involving a reasonable number of patients. A minority of trauma programs have a hybrid OR available to them, and the number of patients who would benefit from it is low. But if a patient needs it, this setup can be life-saving. So who are those patients, exactly?

Tomorrow, which patients may benefit from a hybrid OR?

References:

  1. The evolution of a purpose designed hybrid trauma operating room from the trauma service perspective: The RAPTOR (resuscitation with angiography percutaneous treatments and operative resuscitations). Injury 45:1413-1421, 2014.
  2. The potential benefit of a hybrid operating environment among severely injured patients with persistent hemorrhage: How often could we get it right? J Trauma 80(3):457-460, 2016.
  3. Hybrid treatment combining emergency surgery and intraoperative interventional radiology for severe trauma. Injury 47:59-63, 2016.
  4. The Survival Benefit of a Novel Trauma Workflow that Includes Immediate Whole-body Computed Tomography, Surgery, and Interventional Radiology, All in One Trauma Resuscitation Room. Ann Surg 269(2):370-376, 2019.