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SGEM#181: Did You Ever Have to Make Up Your Mind, Pan Scan or Leave Other Scans Behind?

SGEM#181: Did You Ever Have to Make Up Your Mind, Pan Scan or Leave Other Scans Behind?

Podcast Link: SGEM181

Date: June 3rd, 2017

Reference: Sierink et al. Immediate total-body CT scanning versus conventional imaging and selective CT scanning in patients with severe trauma (REACT-2): a randomised controlled trial. Lancet August 2016.

Guest Skeptic: Dr. Marcel Emond is an Associate Professor, Laval University, Emergency Physician at the Level 1 Trauma Center of the CHU de Québec, a Senior Clinician-Scientist, Chair of CAEP Trauma and Injury prevention committee, BEEM faculty member and the host of SGEM Global French.

Case: A 53-year-old woman in good health is brought in by ambulance after a motor vehicle collision. She did not lose consciousness but did bump her head.  Her main complaint is chest pain with difficulty breathing. She is tachycardic, tachypnic and has some mild abdominal pain. You suspect a flail chest on your clinical examination.  A FAST examination is performed and is negative.

Question: Should trauma patients get an immediate total-body (pan scan) CT or should you do usual X-rays followed by selective CT scanning?

Background: When we assess head or cervical spine injuries there are good clinical decision tools available to Emergency Physicians to guide our care (Canadian CT Head Rules and Canadian C-Spine Rules).

However, when we assess major trauma that includes chest, abdominal and pelvic trauma, the initial radiologic evaluation is left to the treating physician’s judgement. There is no validated clinical decision tool to help guide our decisions.

Many studies (most retrospective) have assessed the use of pan scanning as an initial radiologic evaluation. Huber-Wagner et al (Lancet 2009) showed a mortality reduction in a retrospective database study of patients who have had a pan scan.  The NNT varied from 17 to 32 according to the injury severity.

A systematic review by the authors of the present study confirmed a possible benefit of the pan scan, but it showed a need for a well-designed, large, prospective randomized clinical trial with patient oriented outcomes (Sierink et al 2012).

Reference: Sierink et al. Immediate total-body CT scanning versus conventional imaging and selective CT scanning in patients with severe trauma (REACT-2): a randomised controlled trial. Lancet August 2016.

  • Population: Adults (18 years or older) with severe injury, suspicion of life-threatening injuries or compromised vital signs.
    • Exclusions: Pregnant, referred from another hospital, low-energy trauma with blunt injury mechanism, stab wound in only one body region, and patients too unstable to undergo a CT scan who require CPR or immediate operation because death is imminent
  • Intervention: Immediate total-body CT scan (vertex to pubic symphysis)
  • Comparison: Standard ATLS guideline directed workup that included chest and pelvic x-rays, FAST scan and followed by selective CT scans of individual body regions.
  • Outcome:
    • Primary: In-hospital mortality at initial hospital or secondary hospital if transfer occurred
    • Secondary: 24 hour and 30 day mortality, imaging time, time to diagnosis, length of stay (LOS) in the trauma room or ICU, number of days of mechanical ventilation. cumulative radiation dose, serious adverse events, transfusion requirements, number of missed injuries and hospital costs.
    • Pre-Determined Sub-Group Analysis: Mortality for patients with ISS ≥16 mortality for traumatic brain injury (TBI).

Authors’ Conclusions: “Diagnosing patients with immediate total-body CT does not reduce in-hospital mortality compared to standard radiological work-up. Because of the increase radiation use, future research should focus on the selection of the patient that will benefit from immediate total-body CT.

Quality Checklist for Randomized Control Trials:

  1. checklistThe study population included or focused on those in the emergency department. Yes
  2. The patients were adequately randomized. Yes
  3. The randomization process was concealed. No
  4. The patients were analyzed in the groups to which they were randomized. No
  5. The study patients were recruited consecutively (i.e. no selection bias). Unsure
  6. The patients in both groups were similar with respect to prognostic factors. No
  7. All participants (patients, clinicians, outcome assessors) were unaware of group allocation. No
  8. All groups were treated equally except for the intervention. Unsure
  9. Follow-up was complete (i.e. at least 80% for both groups). Yes
  10. All patient-important outcomes were considered. Yes
  11. The treatment effect was large enough and precise enough to be clinically significant. No

Key results: There were 5,475 patients assessed for eligibility with 3,860 being excluded for a variety of reasons. The most common reason was that they did not meet inclusion criteria.

This left 1,403 patients to be randomly assigned to total-body CT scanning or standard work up. However, another 203 were excluded after randomization, and even more after receiving the allocated intervention. This ultimately left 1,083 for the primary analysis.

No Difference in Mortality

  • Primary Outcome: Mortality 16% vs. 16% p=0.92
  • Secondary Outcomes:
    • 24 Hour Mortality – 8% vs. 6% (p=0.23)
    • 30 Day Mortality – 17% vs. 16% (p=0.69)
    • Imaging Time  – 30min vs. 37min (p<0.0001)
    • Time to Diagnosis – 50min vs. 58min (p<0.001)
    • LOS in Trauma Room – 63min vs. 72min (p=0.067)
    • LOS in the ICU – 3 days vs. 3 days (p=0.83)
    • Number of Days of Mechanical Ventilation – 2 days vs. 1 day (p=0.78)
    • Readmission within Six Months – 17% vs. 11% (p=0.01)
    • Cumulative Radiation Dose ED (median) – 20.9mSv vs. 20.6mSv (p<0.0001)
    • Cumulative Radiation Dose Hospital Admission (median) 21.0mSv vs. 20.6mSv (p<0.0001)
    • Serious Adverse Events – 5 deaths (two in total-body CT group, one in the standard work-up and one patient excluded after randomization)
    • Transfusion Requirements – 27% vs. 28% (p=0.91)
    • Number of Missed Injuries – 9% vs. 10% (p=0.45)
    • Hospital Costs – No significant difference
  • Pre-Determined Sub-Group Analysis: No difference
    • Mortality for patients with ISS ≥16 – 22% vs. 25% (p=0.46)
    • Mortality for Traumatic Brain Injury (TBI) – 38% vs. 44% (p=0.31)

Of note, 46% (n=250) of the control group underwent sequential CT scan of all body regions, equivalent to a total-body scan. Another important point is that there were approximately 10% protocol violators in the two groups.

Screen Shot 2015-04-25 at 3.11.12 PM1) Intervention Choice Bias – This bias may be present in the control group since 46% had an equivalent total-body scan at the end of the radiological work-up. The control group initially had a chest/pelvic CT followed by a protocolized selective CT. One out of two control patients got “selective” head to pelvis evaluations. This may represent a more pragmatic approach.

2) Intention-to-Treat (ITT) Analysis, Cross Overs and Protocol Violators – They say the primary analyses were done “according to the intention-to-treat principle”. In other words, a modified ITT or not an ITT. There were 203 (14%) patients excluded after randomization. Another 117 (8%) patients were excluded after receiving the allocated intervention. So only 78% of the randomized patients were included in the primary analysis.

There were a number of patients who crossed over to the other group (1% intervention group vs. 3% control group). There were also a number of protocol violators (9% Intervention Group vs. 11% Control Group).

3) External Validity –  This study took place in Level 1 Trauma centres in the Netherlands and Switzerland. All were academic teaching hospitals with a trauma team leader and a 64 slice CT scanner. Their results may not be applicable to North American Level 1 Trauma centres or smaller community hospitals without a trauma team leader or 64 slice CT scanner.

4) Statistical vs. Clinical Significance: While some secondary results were statistically significant, it is unlikely that they were clinically significant. Specifically, the slight decrease in time to imaging completed, time to diagnosis and time spent in the trauma room probably are not important.

However, the statistically significantly more radiation in the total-body CT intervention group may/may not be clinically significant. An increase of 0.3 mSv represents an increase cancer risk of 1:30,000.

5) Incidentalomas – The authors mention the risk and complications of incidental findings with total-body CT but they don’t report it. As more and more scans are done there will be more findings of things that will never cause disease (overdiagnosis). However, it can lead to increased stress, anxiety and cost of working up and monitoring the incidentaloma.

Comment on the Authors’ Conclusion Compared to SGEM: We generally agree with the authors’ conclusion.

SGEM Bottom Line: There is no clear evidence that immediate total body scanning of trauma patients provide better clinically important patient oriented outcome but does result in more radiation exposure.

Case Resolution: Your patient has a selective strategy getting a thoracic CT with plain X-rays of the spine and pelvis. A flail chest was identified along with a pneumothorax, which we drained. The patient was then admitted to the trauma service.

Dr. Marcel Emond

Dr. Marcel Emond

Clinical Application: Although this study has some limitations, this paper supports a selective strategy rather than an immediate total body scan in the evaluation of trauma patients. Radiation exposure should be considered before “routinely” using a total-body CT protocol.

What Do I Tell My Patient? You have been in a car accident. We need to get some x-rays and a CT scan. This will show us what you have injured and help us give you the best care possible.

Keener Contest: Last weeks’ winner was Dr. John Hallett from Edinburgh. He knew the first successful pyloromyotomy was performed by Sir Harold Stiles.

Listen to the podcast on iTunes to hear this weeks’ question. The first person to email me with the correct answer at will receive a cool skeptical prize. Don’t forget to use “keener” in the subject line.

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Remember to be skeptical of anything you learn, even if you heard it on the Skeptics’ Guide to Emergency Medicine