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

FRCEM Primary: Cracking the new beast!

FRCEM Primary has now replaced MRCEM Part A exam. The first ever FRCEM Primary exam took place on 7^th December 2016. Most of us were anxious with the new Single Best Answer (SBA) exam pattern, nobody had complete clue what to expect. Only 8 sample questions were provided to us on ‘rcem’ website one month prior to exam ¹.  I have been asked plenty of questions by my colleagues and friends regarding this new beast- FRCEM primary. In the following article, I try to answer the most common questions pertaining to this new exam and my strategies to successfully pass it.

Question 1: How is FRCEM Primary different from MRCEM Part A?

The good thing about RCEM exams is that they have a well-defined syllabus². The syllabus remains the same. The difference is change from true/false to single best answer question. It has its advantages and disadvantages. True/False would give you a 50% chance of getting the answer correct, while single best answer out of 5 options, reduced the chance to 20%. The questions are application based with a clinical vignette, so one can apply knowledge to get the right answer as opposed to true/false, where a candidate either knows or doesn’t know the answer and still has a 50% probability of getting it right.

Based on the above statistics, it is expected that the cut-off scoring also reduces.

Question 2: How difficult was FRCEM Primary exam?

I personally enjoyed solving it. All the questions are clinical cases 2-3 sentences each, they are pretty straight forward and working in Emergency Department helps answer most of the questions. But unless one studies thoroughly it is difficult to pass. Let me give you a perspective, out of 1138 candidates, only 432 passed this exam.

Question 3: How should I start?

I shall tell how I started. Firstly I went through the rcem website. I printed out the syllabus, went through it. Then I immediately started with question banks: frcemexamprep.co.uk & frcemsuccess.com³. I kept a target of at least 50 questions per day for first month, which went to 120-150 by 4^th month. My aim was to learn from questions. It kept me motivated to read. For anatomy (my weakest subject), I used teachmeanatomy as my primary source⁴. For rest of the subjects I heavily relied on the explanation given after questions.

I used Revision Notes for MCEM by Mark Harrison, only in last month as a revision book⁵. It is very dry. This approach helped me remember the questions I solved while reading Mark Harrison. I also referred to Snell’s Anatomy and google search for few topics while solving bank.

Question 4: Should I use question bank? Which ones are the best?

Since no one knew how the exam was going to be, me and my friends subscribed to 2 question banks and took turns solving them. For me question banks were very helpful as they kept me focused and motivated. I tried to give 3-4 hours out of my daily schedule to solve them. The biggest problem that I faced was; if I wasn’t able to solve on a particular day/ days, I would forget everything. It was an eye-opener for me to be consistent throughout my preparation. I can’t say which one is best, I liked frcemexamprep for anatomy as it had pictures and loved frcemsuccess for rest of topics for their thorough explanation.

Question 5: Are the Bromley courses useful?

In retrospect, I definitely find it useful. I took advice from Lakshay and did this course. It is expensive, but worth it. Not mandatory. I went with 2 goals- 1) 2 days revision of entire syllabus and hope of knowing how the questions will be asked and 2) to come back and teach/ share knowledge of what I learnt.

Question 6: Tips for exam day?

a)     Time management: the more questions you do before the exam, easier will be the time management. 3 hours for 180 questions are sufficient.

b)     Stay calm

c)     You have to cross the box on the answer-sheet with pencil, so mark all the questions and if in doubt, at the end you may return to the doubtful answers.

d)     There will be questions pertaining to emergency procedures and its relevance to anatomy/physiology and that of trauma and injury to underlying structures. There will be case scenarios and they may ask mechanism of action of particular drug, drug-drug interaction, etc. See that you read them well.

e)     Read only the volatile section of syllabus on the day of exam- for me it was the nerve supply- sensory/motor and dermatomal distribution (heavily tested).

Summary:

Be consistent. Do plenty of questions. It is a doable exam. Although this was a basic science exam, all questions are about emergency medicine. If you love EM, this will be a fun exam.

If you have any doubts please feel free to contact me at tambe_nikhil@yahoo.co.in

References:

• http://www.rcem.ac.uk/docs/Exams/FRCEM%20Primary%20Sample%20Questions%20for%20Website.pdf
• http://www.rcem.ac.uk/docs/Training/1.4.4%20Basic%20Sciences%20Curriculum.pdf
• http://frcemexamprep.co.uk/
• http://frcemsuccess.com/
• http://teachmeanatomy.info/
• http://www.amazon.in/Revision-Primary-Oxford-Speciality-Training/dp/0198765878/ref=sr_1_2?s=books&ie=UTF8&qid=1484035767&sr=1-2&keywords=frcem+primary

Author:

Nikhil N. Tambe - @nikhil16mar
M.B.B.S., ECFMG (USA)

Emergency Medicine Resident (PGY-2)

Masters in Emergency Medicine (GWU)

Kokilaben Dhirubhai Ambani Hospital, Mumbai

Instructor (American Heart Association)
Lifesupporters Institute of Health Sciences, Mumbai

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

Safe discharge advice: What’s safe for your patient, is safe for you.

A lot of patients come to the emergency department with various issues ranging from a simple fever to other life-threatening conditions like arrhythmias etc. It’s the responsibility of the emergency physician to decide who needs to be admitted and which patients are safe to be discharged home. About 4 out of 5 patients who come to the ED are discharged home.  Failure to provide safe discharge advice can have significant clinical as well as medico-legal consequences. A lack of understanding or providing discharge advice can cause avoidable return to the ED within 72 hours or more, medication non-compliance, dissatisfaction with the care, progression of the illness and even unexpected death.

Why do we fail to provide safe discharge advice?

The most common reasons why we fail to provide safe discharge instructions to the patients are time constraints due to overcrowding in the ED, miscommunication, lack of understanding of the importance of a safe discharge advice, fear of difficult questions from the patient or the attenders, assuming it to be common sense what needs to be done after discharge, hesitance of the patient and attenders to ask questions.

Written vs verbal discharge instructions.

There is little evidence that suggests superiority of written advice over verbal advice. The problem with written instructions is that they can be difficult to comprehend by some and can carry a medico-legal risk to the provider. Some of the problems that can hinder understanding of written advice are uneducated patients, difficult to decipher handwriting of the provider, unclear instructions etc. So, the best method is to provide and document verbal instructions. For eg. “Patient explained about the warning signs of a mild head injury and advised to return to ED if any of them occur”. 

What should the discharge instructions comprise of?

There are 3 key elements to discharge instructions.

1.   Signs and symptoms that warrant return to the ED.

2.   Follow up information.

3.   Clear medication instructions.

Summary:

Safe discharge advice is a process of minimizing the adverse outcomes to a discharged patient to an acceptable minimum. It is an important although often neglected aspect of continued healthcare. ED discharge is a frequent, high-stakes procedure that should be performed with a lot of care. Discharge instructions should be provided keeping the patients’ best interest in mind as well as avoiding medico-legal implications.

Take home points:

1.   Communication is the key.

2.   Provide safe discharge advice to all patients getting discharged from the ED.

3.   Clear verbal advice that is documented is better that written advice.

Author: 

Dr. Mohammed Noor Shoeb,

Junior Consultant - Emergency Medicine at Care Hospitals, Hitech City, Hyderabad.

MRCEM(UK), MBBS.

Email: drshoeb1909@gmail.com

References:

1.   Improving the Emergency Medicine Discharge Process: Environment Scan Report.

2.   EREM: Pitfalls and Perils of Emergency Medicine Discharge Process – Dr. Matthew Delaney, MD.

3.   Safe Discharge: AN Irrational, Unhelpful and Unachievable Process – Dr. S. Goodacre.

4.   The Worrisome Discharged Patient: What do we miss and how do we do better? – Dr. Britlong, MD

5.   Maximizing The Safe Discharge – Amy E Betz, MD.