Trauma Calls and Pan CT - Are we doing it the right way?

Pan CT is almost becoming a norm for trauma, regardless of examination findings. Major Trauma Centers love it. Often patients fit into the "trauma activation" criteria but are stable enough to walk into the ED, look very well and have a completely unremarkable exam. 

Do we really need to activate "trauma call" and involve an anaesthetist, orthopod and surgeon for a patient who walked into the Emergency Department or should we just observe them for a few hours? 

Is it mandatory to scan them if they alert and oriented, look well, are hemodynamically stable but meet a significant injury criteria?

Well, every scenario is different and "pan scanning" and "trauma activation" depends entirely on your gestalt in addition to vital signs and exam findings. A 90 yo on NOACs can develop a Subdural and massive hemothorax due to fall from 3 feet height whereas a 30 year old may not sustain any injuries on falling from a height of 10 feet. My threshold to activate trauma for elderly is much low as minor falls can lead to significant injuries in older adults. But I always get perturbed when I see a patient being discharged (especially young patients) from resuscitation room after a pan-scan! 

There are plenty of other issues with pan scanning:

1. Clinically Insignificant Injuries

We might end up picking clinically insignificant injuries and then ponder what to do with them? Do they just need admission or follow up or a delayed intervention? More importantly, this adds to patient anxiety, additional use of resources. Arguments offered by the proponents of Pan CT are "we never know" and "what if we miss something" etc. Unfortunately, we live in a "no miss" culture and it can be a task to explain this to a distressed patient especially in case of a mishap. But very frequently, patients do understand the pros and cons of radiation and happy to accept minimal risk instead of radiation. Shared decision making (in low risk cases) and safety netting is the way to go rather than pan-scanning. And also remember, clinical examination still remains superior to pan-scans. With all this said, hard findings on exam should certainly mandate a relevant imaging. 

2. Radiation 
More scanning leads to more radiation exposure and higher chances of developing a malignancy in future. Click here to calculate risk of malignancy with various imaging studies. 

3. Skipping examination because we are doing a  CT

Sadly, CT Scanning is now become an excuse for not performing clinical examination. Working under immense pressures of timelines, scans are now being ordered without even evaluating a patient. More than often, physicians are correct in making these decisions but medicine is being practice the other way round where we see the blood results/imaging first and then greet the patient. 

As soon as you enter the room, the patient asks - Is my scan normal? A positive nod cuts the interview very short and saves our time but at the cost of irradiation. Clinical exam is then performed only as a formality. 

Scanning reassures the patients psychologically as well as the treating physician from a medico-legal standpoint. If we are likely to get sued for missing clinically insignificant injuries, then aren't we equally liable to land up in trouble for ordering an unwarranted pan-Scan. 

4. Holding life-saving treatment 

It is unacceptable to hold life saving intervention awaiting CT scan. For instance, decision to insert a chest drain is based on clinical exam and CXR/USG. Subcutaneous emphysema is enough to justify a chest tube insertion even if CXR does not show a clear Pneumothorax. Never withhold a life saving treatment awaiting a CT scan. CT scanning rarely changes the management of blunt chest trauma. In an ideal world, any unstable (hypotensive) trauma should go to OR based on the presumed site of blood loss. Outcomes can be dramatically improved if the Surgeons/Orthopods liaise well with each other. 

CT scans are not a part of primary survey in trauma. As a clinician, you must assess ABCDE at bedside and ensure hemodynamic stability prior to scanning. 

5. Cost and Utilisation of Resources
Pan-Scanning can cost anywhere between 20,000-30,000 INR at a private hospital in India. In government run healthcare systems, the issue is wastage of time and resources. 

The difference between physicians and other healthcare providers is that physicians use clinical judgement, weigh the pros and cons before taking a decision unlike most other allied healthcare workers who are trained to follow the protocols. We all know that everyone brought in with a "high risk" mechanism of injury may not need triple immobilisation, 2 wide bore IVs and Rectal Exams. Protocols are always made with a valid rationale behind them and should always have some degree of flexibility based on the clinical acumen of treating physician. 

Guidelines are made to guide us, not to be followed as hard and fast rules. 

Summary:

Patients who require pan-CT should be carefully selected based on gestalt, mechanism, vital signs and exam findings and not just based on the mechanism. Also, consider pan-scanning for those with difficult body habitus and altered mental status (of course with some clinical judgement). We need to be more responsible when we use the power of technology and make sure everything is done keeping in mind the best interests of our patients. There is something grossly wrong if we are frequently discharging patients from ED after pan scanning (This means we suspected multiple external or internal injuries on examination, but found none on Scanning). Consider observation and good safety netting in patients with low likelihood of injuries. Likewise, Trauma Call Activation needs to be individualised and we should not be blinded by the "high risk mechanism". 

Further Reading:

1. Surendran A, et al. Systematic review of the benefits and harms of whole-body computed tomography in the early management of multitrauma patients: are we getting the whole picture? J Trauma Acute Care Surg. 2014 Apr; 76(4):1122-30.
2. Holmes JF, Wisner DH, McGahan JP, et al. Clinical prediction rules for identifying adults at very low risk for intra-abdominal injuries after blunt trauma. Ann Emerg Med. 2009; 54:575-584. 
3. http://stemlynsblog.org/jc-always-need-whole-body-ct-trauma-st-emlyns/
4. http://thesgem.com/2017/06/sgem181-did-you-ever-have-to-make-up-your-mind-pan-scan-or-leave-other-scans-behind/
5. http://www.thebottomline.org.uk/summaries/em/react-2/
6. Kroczek EK, Wieners G, Steffen I, et al
   Non-traumatic incidental findings in patients undergoing whole-body computed tomography at initial emergency admission
   Emerg Med J  Published Online First: 27 January 2017. doi: 10.1136/emermed-2016-205722

7. Immediate total-body CT scanning versus conventional imaging and selective CT scanning in patients with severe trauma (REACT-2): a randomised controlled trial Sierink, Joanne C et al. The Lancet , Volume 388 , Issue 10045 , 673 - 683

   
   
   

   
   

   Posted by:

              

     Lakshay Chanana

     

     Speciality Doctor

     Northwick Park Hospital

     Department of Emergency Medicine

     England

     @EMDidactic

AP View and Common C-Spine injuries - Part 3

Long AP view checklist
While interpreting the AP view of C-Spine, address these two questions:

1. Are all the spinous processes in a straight line? (Red and Blue vertical lines)
If not, consider a rotational injury.

2. Look for approximately equal height of each vertebra and also spaces between adjacent spinous processes? (Light green arrows and small blue X marks)

Common Fractures 
Most C-spine injuries are managed with immobilisation or surgical repair. Indications for surgical intervention are:

1. Neurological Deficits
2. Severe Pain
3. Unstable Spine

Jefferson's fracture (burst # of atlas due to axial loading)
X-Ray display outward displacement of lateral masses on open-mouth view. It is treated with hallo immobilisation/ surgical repair. 

Hangman's fracture: Fracture of both pedicles of C2 that occurs due to hyperextension of neck. It is treated with halo immobilisation/ surgery. 

Odontoid (Peg) Fractures
Type 1 - Philadelphia collar
Type 2 - Halo vest/ Surgical Repair
Type 3 - Halo vest

Vertical Compression fracture (Treated with traction/immobilisation)

Unilateral facet dislocation: On a lateral view, the involved vertebral body will be displaced <50% of its width. On anterior view, there is rotation of the involved vertebra, with the affected spinous process pointing toward the side that is dislocated. 

Bilateral facet dislocation: The vertebral body is dislocated anteriorly at least 50% of its width. These injuries usually present with neurologic deficits. 

Clay Shoveler's fracture i.e. Avulsion off the end of one of the lower cervical spinous processes, classically describes with C7. Rx with a soft collar. 

Images taken from:
https://www.med-ed.virginia.edu/courses/rad/cspine/interpretation8.html
http://newnurseblog.com/2010/11/17/spinal-precautions/halo/
https://radiopaedia.org/articles/hangman-fracture
http://www.radiologyassistant.nl/en/p49021535146c5/spine-cervical-injury.html

The obsolete C-Spine X-Rays - Part 2

AP View (Peg view)

The stability of C1-2 depends mainly on the transverse ligament. When looking at peg view, watch out for these three things:

1. Vertical Alignment of lateral margins of C1 and C2 (Vertical white lines in the image below) - If there is vertical misalignment of the masses then consider four possibilities - ligament injury, burst fracture of C1 (Jefferson #), rotation or developmental variation.

Slight neck rotation can often lead to unequal appearing spaces on either side but if this is the case, then lateral masses of C1 and C2 remain normally aligned.

2. Spaces on both sides of Peg should be approximately equal (Horizontal white lines in the image below) - Normal distance between peg and the lateral masses on each side is between 3-5mm.

Laterally displaced lateral masses (Jefferson #))

Rotated film leading to unequal distance on one side of peg

3. Look if there is a fracture on the base of the peg

Peg fracture

Beware of the Mach effect - an optical illusion which appears like a fracture through the base of peg.

Make a note of the horizontal black line crossing the base of peg - MACH EFFECT

Images taken from:
http://www.mediconotebook.com/2013/05/jefferson-fracture.html
https://www.ceessentials.net/article15.html

The obsolete C-Spine X-Rays - Part 1

In this day and age, most hospitals and certainly all the trauma centres prefer to CT Cervical-spine rather than performing a series of Cervical Spine X rays. Few centres have gone a step beyond, where they perform a head to pelvis (PAN-CT) scan PRIOR to resuscitation, which is then followed by simultaneous Clinical and CT based ABCD assessment.

That said, I believe that C-Spine X rays still hold a place in the developing world where cost becomes a significant issue during management of trauma victims. Emergency Physicians often get caught up in financial discussions with patients and their families, therefore we need to choosy while ordering blood investigations and imaging studies. And also, C-Spine X-Rays is a good way to start evaluating low risk injuries. In this three part series, I intend to provide a framework and stepwise interpretation of C-Spine X-Rays. 

Trauma C Spine views:

1. AP
2. Lateral
3. Open Mouth (Peg View)

• Swimmer's view: It is named after the swimming stroke referred to as freestyle. This view can be requested in addition to standard 3 trauma views to demonstrate the upper thoracic  and the seventh cervical vertebrae.

The most common reasons for missed injuries is inadequate films (which fail to show C7-T1 junction) and poor understanding of C1-C2 anatomy.

Anatomy Review

Key Points: It is critical to understand C1-C2 anatomy. C1 vertebra lacks a body. C1 instead has a ring which incorporates the odontoid process (odontoid process = dens = peg) of C2 vertebra. Often, these three different names for odontoid process cause a bit of confusion. I am going to refer to it as "peg" for the rest of this post. 

Look at the images below to visualise C1-C2 anatomy. Peg (labelled as odontoid process of C2 in the image below) sits between the Anterior Arch of Atlas (C1 vertebra is also called as Atlas) and transverse ligament. 

Peg is labelled as Dens the all the above 3 (Ant,Post and Lateral) images

See how peg (also known as odontoid/dens) fits into the ring of C1 vertebra seen from the lateral view

Lateral View (STEPS)

1. Assess adequacy of the film (Is C7-T1 junction seen? - Avoid interpreting inadequate films. Patients with inadequate films need a CT scan. Swimmer's view can be used as an adjunct to improve visualisation due to poor body habitus. At the outset, choose a CT over X-rays in difficult body habitus and elderly. 

Inadequate film (C7-T1 not visualised)

Adequate (C7-T1 junction seen)

                                       

Swimmer's view

2. Identify the Anterior Arch of Atlas (AAA) and measure the distance between AAA and Peg (< 3mm in Adults and < 5mm in Kids) - Increased space between these two structures suggests transverse ligament injury.

Pre-dental space on X Tay

3. Identify Peg: Anterior cortex of peg should be continuous with the body of C2 (Remember, Peg itself is a part of C2) and the posterior cortex of the peg should be in continuation with the posterior cortex of body of C2. Any break in the anterior or posterior cortex indicates a Peg fracture.

Image of Left - Not the that the anterior cortex of peg continuous with the body of C2 and the posterior cortex of the peg is in continuation with the posterior cortex of body of C2. Image on Right- Obvious step in the continuity of C1-2 indicating peg #. This finding may not be very prominent. 

4. Identify Harris Ring - A white incomplete ring seen at the base of peg which is occasionally incomplete at inferior and superior aspects (This is NORMAL). If the anterior or posterior margin of the ring looks disrupted, suspect a fracture thru the base of peg or C2 body.

Harris Ring, Marked with black Arrow heads. Look at all the above images now and try to localise the harris ring.

5. Look at the THREE Lines, heights of all the vertebra and pre vertebral soft tissues: 

• Each line should run smoothly without any steps. 
• The anterior and posterior heights of vertebra should be approximately same
• Any swelling on the soft tissues shadows anterior to the vertebra indicates haemorrhage. However, the absence of swelling cannot exclude an injury. So be worried if you increase in the width of pre-vertebral soft tissues but don't be reassured completely if it looks normal. Remember these numbers (3x7=21)

Pre-dental space - < 3mm in adults
Pre-vertebral Soft tissues width at C1-4 - < 7mm

Pre-vertebral Soft tissues width at C5-7 - < 21mm

Images taken from:

• http://www.shutterstock.com/pic-415445710/stock-photo-cervical-spine-structure-vertebral-bones-cervical-bones-anatomy-of-human-bone-system-human.html
• http://www.aafp.org/afp/1999/0115/p331.html
• https://www.med-ed.virginia.edu/courses/rad/cspine/interpretation1.html
• https://www.ceessentials.net/article20.html
• http://accessemergencymedicine.mhmedical.com/searchResults.aspx?q=jefferson+fracture&f_SemanticFilterTopics=jefferson+fracture&fl_SiteID=52&fl_TopLevelContentDisplayName=Images&adv=True
• http://clinicalgate.com/cervical-spine-5/
• https://www.studyblue.com/notes/note/n/radiology-c-spine-neck/deck/8336200