Tag Archives: ct scan

Best of AAST 2022 #4: The “Hybrid ER” – Again?

Two years ago, an abstract was presented at this meeting describing the concept of the “hybrid ER.” Check it out using this link. This concept was pioneered in Japan, and consists of a special trauma resuscitation room in the ED with everything but an operating room built into it. It’s possible to perform whole-body CT scan, interventional procedures, and REBOA without moving the patient. Here’s a picture from that abstract:

A = CT scanner   B = CT exam table   C = movable C-arm   D = monitor screen   E = ultrasound   F = ventilator

In that abstract, about a thousand patients were compared with two thirds in the hybrid ER group and one third undergoing conventional evaluation. The authors concluded that mortality was significantly improved in the hybrid ER group, and even more so in high ISS patients.

I had a lot of questions for that abstract that were answered in the subsequently published manuscript (reference 2). The authors have updated their experience using new data from the last five years. They created a new approach to resuscitation that is different than the usual ATLS sequence for select patients. Here’s the algorithm they used:

The primary survey is completed, then the patient undergoes a quick whole body CT scan. After that, the secondary survey progresses and any necessary emergency procedures are performed.

In this abstract, the authors compared a group of 46 patients who underwent standard ATLS evaluation with 49 who received the expedited process, which they termed CT First Resuscitation (CTFR). All patients had presumptive hemorrhagic shock based on prehospital vital signs. The authors analyzed injury patterns, interventions performed, timing, adverse events, and outcome. Demographics and injury severity were similar in the two groups.

Here are the factoids:

  • Time to CT in the CTFR group was significantly shorter (1.5 min vs 15 min)
  • The expedited scan settings for CTFR resulted in blindingly fast scan times (median 56 seconds)
  • None of the CTFR patients decompensated during the scan process
  • There was no difference in mortality between CTFR and standard evaluation (14% vs 4%, p=.1)
  • There was no difference in time to hemostatic intervention (56 vs 59 minutes)
  • There was no difference in red cell transfusions (no units in either group)

The authors concluded that CTFR expedited trauma management without adverse effects, and there was no increase in mortality. They, or course, recommended further study.

Bottom line: Several trauma surgeons from a variety of centers wrote an invited commentary last year (reference 3) expressing their excitement about this concept. Reducing time to definitive control of hemorrhage has been repeatedly shown to improve survival. The hybrid ER is one way of reducing those times by eliminating most of the time needed to move the patient about and providing everything but an operating room in the emergency department.

But they also recognized the limitations of this concept. The changes to the ED physical plant are extreme and involve the installation of very expensive equipment that must be heavily shielded from the rest of the emergency department. There are also significant differences in physician training and hospital reimbursement between Japan and the US. This will probably severely limit the adoption of this technology in the States.

I believe that this is an important study showing the feasibility of this method of evaluation. Unfortunately, it does not allow us to draw any real conclusions about safety and efficacy due to the low numbers of patients enrolled. I agree with the authors that a larger study should be performed so we can truly determine whether this concept can possibly be applied outside of Japan.

Here are my questions for the authors / presenter:

  1. Did you perform a power analysis? I doubt that the sample size reported would allow for any findings of statistical significance with the exception of huge differences like time to CT.
  2. How do you protect the trauma team from radiation exposure? Since these patients are in shock when they arrive, I assume that the team cannot leave the room. CT scan radiation exposure of the team is significantly higher than a chest and pelvis x-ray. Repeated team exposure may pose risks.
  3. Does the trend toward higher mortality in the CTFR group trouble you? Sure, it is not statistically significant. But it is approaching significance with a small sample group.
  4. Why didn’t the CTFR group have more rapid hemostatic intervention? One would think these early results could help move the patient to an OR more quickly. And why did it take an hour? Isn’t that a long time?
  5. Why didn’t your patients receive any blood? Weren’t they supposed to be at risk for hemorrhagic shock? How did you treat it without blood? Perhaps your selection criteria need to be tweaked.

This is a nice follow on study from the previous presentation two years ago. It could be an exciting advance in resuscitation, but we need much more info to pass judgement. I’m looking forward to the presentation.

References:

  1. COMPUTED TOMOGRAPHY FIRST RESUSCITATION WITH HYBRID EMERGENCY ROOM FOR SEVERELY INJURED PATIENTS. Plenary paper #25, AAST 2022.
  2. Hybrid emergency room shows maximum effect on trauma resuscitation when used in patients with higher severity. J Trauma Acute Care Surg. 2021 Feb 1;90(2):232-239.
  3. Time to Hemorrhage Control in a Hybrid ER System: Is It Time to Change? Shock. 2021 Dec 1;56(1S):16-21.

The Role Of Postop CT Scan In Penetrating Trauma

CT scans are commonly used to aid the workup of patients with blunt trauma. They are occasionally useful in penetrating trauma, specifically when penetration into a body cavity is uncertain and the patient has no hard signs that would send him or her immediately to the operating room.

Is there any role in operative penetrating trauma, after the patient has already been to the OR? The dogma has always been that the eyeballs of the surgeon in the OR are better than any other imaging modality. Really? The surgical group at San Francisco General addressed this question by retrospectively reviewing 6 years of their operative penetrating injury registry data. They were interested in finding how many occult injuries (seen with CT but not by the surgeon) were found on a postop CT. A total of 225 patients who underwent operative management of penetrating abdomen or chest injury were included. Here are the factoids:

  • Only 110 patients had a postop CT scan; 73 had scans within the first 24 hours, the other 37 were scanned later
  • Rationale for early scan was to investigate retroperitoneal injury in half of patients, but frequently no indication was given (41%)
  • Rationale for late scan was for workup of ileus in one third, or for evaluation of new or unexpected clinical problems
  • Occult injuries were found in about half of early CT patients (52%), and 22% of late CT patients
  • The most common occult injuries were fractures, GU issues, regraded solid organ injury, and unrecognized vascular injuries
  • Ten patients had management changes, including:
    • Interventional radiology for four injuries with extravasation
    • Operation for orthopedic or GU injury in seven patients
    • One patient underwent surgery for an unstable spine fracture

Bottom line: There appears to be a significant benefit to sending some penetrating injury patients to CT in the early postop period. Specifically, those with injury to the retroperitoneum, deep into the liver, near the spine, or with multiple and complicated injuries would benefit. Simple stabs and gunshots that stay away from these areas/structures probably do not need followup imaging. 

Reference: Routine computed tomography after recent operative exploration for penetrating trauma: What injuries do we miss? J Trauma 83(4):575-578, 2017.

Best Practice: Use of CT Scan In Trauma Activations – Part 2

In my last post, I described how the unscheduled and random use of CT scan in trauma activations can interfere with normal radiology department workflow, creating access problems for other emergency and elective patients. Today, I’ll detail a project implemented at my hospital to analyze the magnitude of this problem and try to resolve it.

We started with a detailed analysis of how the scanner was being used for trauma activation patients. Regions Hospital has a single-tier trauma activation system, with no mechanism of injury criteria other than penetrating injury to the head, neck, and torso. There were usually about 850highest-level activations per year at the time, and traditionally the CT scanner had been “locked down” when the activation is announced. The CT techs would complete the current study on the table, then hold the scanner open until called or released by the trauma team.

Since we are a predominantly blunt trauma institution, we scan most stable patients. Our average time in the trauma bay is a bit less than 20 minutes. Add this time to the trauma activation prenotification time of up to 10 minutes, and the scanner has the potential to sit idle for up to half an hour. And in some cases when scan is not needed (minor injuries, rapid transport to OR) the techs were not notified and were not aware they could continue scanning their scheduled cases.

A multidisciplinary group was created and started with direct observation of the trauma activation process and a review of chart documentation and radiology logs. On average it was calculated that the scanner was held idle for an average of 17.9 minutes too long. This is more than enough time to complete one, or even two studies!

A new process was implemented that required the trauma team leader to call out to the ED clerk placing orders for the resuscitation 5 minutes before the patient would be ready for scan. I still remember the first time this happened to me. I was so used to just packing up and heading to scan, I got a little irritated when told that I hadn’t made the 5-minute call. But it’s a good feedback loop, and I never forgot again!

We studied our workflow and results over a 9-week period. And here are the factoids:

  • The average CT idle time for trauma activations before the project was 17.9 minutes
  • This decreased to an average idle time of 6.4 minutes during the pilot project
  • Total idle time for all activations was 8.3 hours, but would have been 36 hours under the old system
  • A total of 28.6 hours were freed up, which allowed an additional 114 patients to be scanned while waiting for the trauma activation patients

This was deemed a success, and the 5-minute rule is now part of the routine flow of our trauma activations. We rarely ever have to wait for CT, and if we do it’s usually due to the team leader not thinking ahead.

Bottom line: This illustrates the processes that should be used when a quality problem surfaces in your program:

  • Recognize that there is a problem
  • Convene a small group of experts to consider the nuances
  • Generate objective data that describes the problem in detail
  • Put on your thinking caps to come up with creative solutions
  • Test the solutions until you find one that shows the desired improvement
  • Be prepared to modify your new systems over time to ensure they continue to meet your needs

Best Practice: Use of CT Scan In Trauma Activations – Part 1

Computed tomography is an essential part of the diagnostic workup for many trauma patients. However, it’s a limited resource in most hospitals. Only so many scanners are affordable and available.  Typically, trauma centers have a scanner located in or very near the trauma bay, which makes physical access easy. Others may be located farther away, which can pose logistical and safety issues for critically injured patients.

Even if the CT is close to the ED, availability can be an issue. This availability applies not only to trauma scans, but to others as well. There is an expectation that CT be immediately available when needed for trauma activation patients. However, chances are that the same scanner is also used for high priority scans for services other than trauma, such as stroke evaluation.

Who gets the scanner first? Obviously, many trauma patients need rapid diagnosis for treatment of their serious injuries. But a fresh stroke patient also has a neurologic recovery countdown clock running if they might be eligible for lytic administration.

And don’t forget that trauma and stroke aren’t the only services vying for that scanner. The hospital undoubtedly has a stream of elective scans queued up for other in-house patients. Every urgent or emergent scan needed for trauma sets the elective schedule back another 30 minutes or more.

How does your trauma center manage CT scan usage for trauma? The vast majority essentially lock it down at some fixed point. This is typically either upon trauma activation, or at patient arrival. The former is very common, but also very wasteful because there can be a significant wait for the patient to actually arrive. Then add on the time it takes to complete the trauma bay evaluation. Up to an hour may pass, with no throughput in the CT scanner. This can be a major work flow headache for your radiology department.

Is there another way? My center was one of those that stopped the scanner after the current patient was finished at the time the trauma activation was called. We have two scanners just 30 feet from the trauma bays, so one could continue working while the other was held. However, this cut their throughput by 50% for roughly half an hour. We recognized that this was a creating a problem for the whole hospital, so we worked with the radiology department to come up with a better way.

In my next post I’ll detail the new system we implemented, and provide data showing the real impact of this new system on CT scan productivity.

Arms Up or Arms Down In Torso CT Scans?

CT scan is a valuable tool for initial screening and diagnosis of trauma patients. However, more attention is being paid to radiation exposure and dosing. Besides selecting patients carefully and striving for ALARA radiation dosing (as low as reasonably achievable) by adjusting technique, what else can be done? Obviously, shielding parts of the body that do not need imaging is simple and effective. But what about simply changing body position?

One simple item to consider is arm positioning in torso scanning. There are no consistent recommendations for use in trauma scanning. Patients with arm and shoulder injuries generally keep the affected upper extremity at their side. Radiologists prefer to have the arms up if possible to reduce scatter and provide clearer imaging.

Radiation physics research has examined arm positioning and its effect on radiation dose. A retrospective review of 690 patients used dose information computed by the CT software and displayed on the console. Radiation exposure was estimated using this data and was stratified by arm positioning. Even though there are some issues with study design, the results were impressive.

The dose results were as follows:

  • Both arms up: 19.2 mSv (p<0.0000001)
  • Left arm up: 22.5 mSv
  • Right arm up: 23.5 mSv
  • Arms down: 24.7 mSv

Bottom line: Do everything you can to reduce radiation exposure:

  1. Be selective with your imaging. Do you really need it?
  2. Work with your radiologists and physicists to use techniques that reduce dose yet retain image quality
  3. Shield everything that’s not being imaged.
  4. Think hard about getting CT scans in children
  5. Raise both arms up during torso scanning unless injuries preclude it.

Reference: Influence of arm positioning on radiation dose for whole body computed tomography in trauma patients. J Trauma 70(4):900-905, 2011.