#53 – Ottawa Rules



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Background

  • These studies are conducted at the Ottawa Hospital Research Institute and University of Ottawa starting in 1992 and the main researcher behind these is Ian Stiell.
  • They are international recognized and have been validated multiple times to decrease unnecessary radiographic testing and decrease healthcare costs

Disclaimer for Using Clinical Decision Instruments

  • Your clinical judgement should ALWAYS trump using any CDI
    • Distracting injuries
    • Intoxication
    • Inability to fully examine
    • Gestalt

Ottawa Rules of the Foot and Ankle

  • The Numbers
    • Ankle xrays are the second most commonly ordered film in the ED
    • < 15% fracture incidence rate
  • The study
    • Published in 1992, validated in 1995
    • 7 months long
    • 750 patients
    • 21 EM physicians looking at 32 clinical variables
  • Variables
    • Lateral malleolus tenderness
    • Medial malleolus tenderness
    • Base of 5th metatarsal tenderness
    • Navicular tenderness
    • Inability to bear weight immediately and in the emergency department for four steps
      • Limping counts
  • Outcomes
    • Identified 100% of clinically significant fractures
    • Decreased ankle imaging 36% and foot imaging 21%
  • Clinical Pearls
    • Be sure to palpate the entire 6cm of the distal tibia and fibula
    • Do not confuse soft tissue tenderness for bony tenderness

Ottawa Rules of the Knee

  • The Numbers
    • >600,000 patients annually present to ED with knee complaints
    • 80% of these patients have radiography
      • Majority have soft tissue injuries
  • The study
    • Published in 1995, validated in 1996
    • 14 months long
    • 1,047 patients
    • 33 EM physicians looking at 23 clinical variables
  • Variables
    • > 55 years of age
    • Isolated patella tenderness
    • Fibular head tenderness
    • Inability to flex knee to 90o
    • Inability to bear weight immediately and in the emergency department for four steps
      • Limping counts
  • Outcomes
    • Identified 100% of clinically significant fractures
    • Decreased knee imaging by 28%
  • Clinical Pearls
    • Use only for injuries < 7 days old
    • Patella tenderness only significant if an isolated finding

Ottawa Rules of the Cervical Spine

  • The Numbers
    • C-spine series is the most common radiograph for trauma
    • > 1,000,000 series performed annually
      • > 98% being negative
  • The study
    • Published in 2001, validated in 2003
    • 3 years long
    • 8,924 patients
      • Blunt trauma only
      • Stable vital signs
      • GCS of 15
    • Looked at 20 clinical variables
  • Variables
    • ≥ 65 years of age
    • Dangerous mechanism
      • Fall from height > 3 feet or 5 stairs
      • Axial load
      • High speed (> 60mph) MVC, rollover, or ejection
      • Motorized recreational vehicle accident
      • Pedestrian or cyclist versus automobile accident
    • Immediate pain
    • Non-ambulatory at scene
    • Inability to rotate neck
  • Outcomes
    • Identified 100% of clinically significant fractures
    • Decreased cervical spine imaging by 42%
  • Clinical Pearls
    • Not applicable if:
      • Non-trauma
      • GCS < 15
      • Unstable vital signs
      • Age < 16 years of age
      • Acute paralysis
      • Known vertebral disease
      • Previous cervical spine history

Canadian Head CT Rule

  • The Numbers
    • > 2 million ED visits annually for minor head trauma
      • Average cost of CT scan ~ $1200
        • Average annual cost > $900 million
    • < 3% incidence of clinically significant intracranial injuries
  • The study
    • Published in 2001, validated in 2005
    • 3 years long
    • 3,121 patients
      • Blunt trauma only
      • GCS between 13-15
      • < 24 hours on presentations
      • Must have loss of consciousness, altered mental status, or amnesia
    • Across 10 academic hospitals
    • Looked at 22 clinical variables
  • Variables
    • High risk variables (need for neurosurgical intervention)
      • GCS < 15 at 2 hour after injury
      • Suspected open/depressed skull fracture
      • Signs of basilar skull fracture
      • ≥ 2 episodes of vomiting
      • ≥ 65 years of age
  • Variables
    • Medium risk variables (predicting clinically important brain injury)
      • Retrograde amnesia ≥ 30 minutes
      • Dangerous mechanism
        • Pedestrian versus auto
        • MVC ejection
        • Fall from height > 3 feet or > 5 stairs
  • Outcomes
    • Identified 100% of high risk patients and 98.4% of medium risk patients
    • Reduction in head CT by > 30%
  • Clinical Pearls
    • Not applicable if:
      • < 16 years of age
      • On anticoagulation
      • Witnessed seizure post-injury
      • Unstable vital signs
      • Acute focal neurologic deficit

Ottawa Rules for Subarachnoid Hemorrhage

  • The Numbers
    • 2% of all ED visits are for headache
    • 2% incidence of subarachnoid hemorrhage
    • 51% mortality if missed
  • The study
    • Published in 2010, validated in 2013
    • 5 years long
    • 1999 patients
      • Non-traumatic
      • < 1 hour from onset
      • GCS 15
    • Looked at 13 clinical variables
  • Variables
    • ≥ 40 years of age
    • Neck pain
    • Witnessed loss of consciousness
    • Exertional onset
    • Added on validation study:
      • Thunderclap headache
      • Limited neck flexion on exam
  • Outcomes
    • Identified 100% of subarachnoid hemorrhages
    • 100% negative predictive value
    • Decreased head CT or lumbar puncture rates by 20%

The Cottage Physician (1893)



References

  1. The Ottawa Rules. [online] Available at: http://www.theottawarules.ca/ [Accessed 10 Nov. 2019].
  2. Stiell IG, Greenberg GH, McKnight RD, Nair RC, McDowell I, Worthington JR. A study to develop clinical decision rules for the use of radiography in acute ankle injuries. Annals of emergency medicine. 1992; 21(4):384-90. [pubmed]
  3. Stiell IG, Greenberg GH, McKnight RD, et al. Decision rules for the use of radiography in acute ankle injuries. Refinement and prospective validation. JAMA. 1993; 269(9):1127-32. [pubmed]
  4. Stiell IG, McKnight RD, Greenberg GH, et al. Implementation of the Ottawa ankle rules. JAMA. 1994; 271(11):827-32. [pubmed]
  5. Stiell I, Wells G, Laupacis A, et al. Multicentre trial to introduce the Ottawa ankle rules for use of radiography in acute ankle injuries. Multicentre Ankle Rule Study Group. BMJ (Clinical research ed.). 1995; 311(7005):594-7. [pubmed]
  6. Stiell IG, Greenberg GH, Wells GA, et al. Derivation of a decision rule for the use of radiography in acute knee injuries. Annals of emergency medicine. 1995; 26(4):405-13. [pubmed]
  7. Stiell IG, Greenberg GH, Wells GA, et al. Prospective validation of a decision rule for the use of radiography in acute knee injuries. JAMA. 1996; 275(8):611-5. [pubmed]
  8. Stiell IG, Wells GA, Hoag RH, et al. Implementation of the Ottawa Knee Rule for the use of radiography in acute knee injuries. JAMA. 1997; 278(23):2075-9. [pubmed]
  9. Stiell IG, Wells GA, Vandemheen KL, et al. The Canadian C-spine rule for radiography in alert and stable trauma patients. JAMA. 2001; 286(15):1841-8. [pubmed]
  10. Stiell IG, Clement CM, McKnight RD, et al. The Canadian C-spine rule versus the NEXUS low-risk criteria in patients with trauma. The New England journal of medicine. 2003; 349(26):2510-8. [pubmed]
  11. Stiell IG, Wells GA, Vandemheen K, et al. The Canadian CT Head Rule for patients with minor head injury. Lancet (London, England). 2001; 357(9266):1391-6. [pubmed]
  12. Stiell IG, Clement CM, Rowe BH, et al. Comparison of the Canadian CT Head Rule and the New Orleans Criteria in patients with minor head injury. JAMA. 2005; 294(12):1511-8. [pubmed]
  13. Perry JJ, Stiell IG, Sivilotti ML, et al. High risk clinical characteristics for subarachnoid haemorrhage in patients with acute headache: prospective cohort study. BMJ (Clinical research ed.). 2010; 341:c5204. [pubmed]
  14. Perry JJ, Stiell IG, Sivilotti ML, et al. Clinical decision rules to rule out subarachnoid hemorrhage for acute headache. JAMA. 2013; 310(12):1248-55. [pubmed]

PAINE #PANCE Pearl – Neurology



Question

There are two tests that you can perform at bedside in patients with suspected myasthenia gravis. One is an easy adjunct to the neurologic exam and the other is only included for historical purposes. Name these tests.



Answer

The most reliable way to diagnose myasthenia gravis is through serologic laboratory studies assessing acetylcholine receptor and muscle-specific tyrosine kinase antibodies. But……………there are two bedside tests that can help prior to expensive labs.

  • Ice Pack Test
    • Used as part of the neurologic examination, it is based on the physiologic principle that neuromuscular transmission improves at lower muscle temperature. In patients with myasthenia gravis, placing an ice pack over a closed eyelid for 2 minutes can improve ptosis in 80% of patients.
https://www.nejm.org/doi/full/10.1056/NEJMicm1509523
  • Edrophonium Test
    • Taught more for historical purposes, edrophonium is an acetylcholinesterase inhibitor with a rapid onset and short duration of action. The main effect is prolonging acetylcholine in the neuromuscular junction to improve muscular strength.
    • It is not available in the US, nor used in the diagnosis

Ep-PAINE-nym



Adie’s Pupil

Other Known Aliases – Holmes-Adie pupil

Definition – pupil with parasympathetic denervation that constricts poorly to light, but reacts better to accommodation.

Clinical SignificanceThe tonic pupil is the result of damage to the parasympathetic ciliary ganglion and the exact pathological cause is still unknown, but infectious inflammation to the ciliary ganglion is the most commonly accepted etiology. Adie’s pupils are hypersensitive to very low dose acetylcholine agonists, such as pilocarpine, and is used to diagnose this condition.

HistoryNamed after William John Adie (1886-1935), who was a British physician and neurologist and received his medical doctorate from the University of Edinburgh in 1911. Upon graduating, he served in the British military during World War I as a medical officer. Following the war, he worked in various hospitals practicing neurology and making a name for himself, culminating in Fellowship in the Royal College of Physicians in 1926. He was also one of the founders of the Association of British Neurologists in 1932. The history of the eponym is interesting because there were numerous publications prior to Adie’s work describing this clinical syndrome and Adie referenced them in his 1931 article. The eponymonic term was given to him by French neurologist Jean-Alexandre Barré in 1934. Also, Gordon Morgan Holmes contemporaneously published the same findings in the same year. This led to the common eponym Holmes-Adie pupils.


References

  1. Firkin BG and Whitwirth JA.  Dictionary of Medical Eponyms. 2nd ed.  New York, NY; Parthenon Publishing Group. 1996.
  2. Bartolucci S, Forbis P.  Stedman’s Medical Eponyms.  2nd ed.  Baltimore, MD; LWW.  2005.
  3. Yee AJ, Pfiffner P. (2012).  Medical Eponyms (Version 1.4.2) [Mobile Application Software].  Retrieved http://itunes.apple.com.
  4. Whonamedit – dictionary of medical eponyms. http://www.whonamedit.com
  5. Up To Date. www.uptodate.com
  6. Adie WJ. Pseudo-Argyll Robertson pupils with absent tendon reflexes. A benign disorder simulating tabes dorsalis. British Medical Journal, London, 1931, I: 928-930. [article]
  7. Holmes GM. Partial iridoplegia associated with symptoms of other disease of the nervous system. Transactions of the Ophthalmological Societies of the United Kingdom, 1931, 51: 209-228.

Ep-PAINE-nym



Ménière’s Disease

Other Known Aliasesendolymphatic hydrops

Definitionabnormal fluid and ion homeostasis of the inner that leads to distortion and distention of the membranous, endolymph-containing portions of the labyrnthine system. It is currently unclear why this occurs and several etiologies have been proposed.

Clinical SignificanceMénière’s disease classically has the triad of tinnitus, sensorineural hearing loss, and episodic vertigo lasting from 20 minutes to 24 hours. The course and severity are variable and the frequency may actually decline over time. Treatment is geared towards diet and lifestyle modifications, vestibular suppressants, diuretics, and interventional procedures in severe or refractory cases.

HistoryNamed after Prosper Ménière (1799-1862), who was a French physician and recieved his medical doctorate from the Hôtel-Dieu de Paris in 1828. He studied and assisted Guillaume Dupuytren at this famed hospital in France. During a particularly bad outbreak of cholera, he was sent by the king to Aude and Haute-Garonne to oversee this medical campaign and was so successful that he was made a knight of the Legion of Honour. Later, he became chief of medicine at the Imperial Institution for Deaf Mutes in Paris and published his findings on his eponymous disease in 1861.


References

  1. Firkin BG and Whitwirth JA.  Dictionary of Medical Eponyms. 2nd ed.  New York, NY; Parthenon Publishing Group. 1996.
  2. Bartolucci S, Forbis P.  Stedman’s Medical Eponyms.  2nd ed.  Baltimore, MD; LWW.  2005.
  3. Yee AJ, Pfiffner P. (2012).  Medical Eponyms (Version 1.4.2) [Mobile Application Software].  Retrieved http://itunes.apple.com.
  4. Whonamedit – dictionary of medical eponyms. http://www.whonamedit.com
  5. Up To Date. www.uptodate.com
  6. Ménière P. Sur une forme particulière de surdité grave dépendant d’une lésion de l’oreille interne. Gazette médicale de Paris. 1861;S3(16):29.

PAINE #PANCE Pearl – Pediatrics



Question

A 3-week old baby girl is sent to your emergency department after being seen by their pediatrician for irritability, poor feeding, and a seizure just prior to arrival at the pediatrician’s office. Vital signs are BP-103/73, HR-137, RR-25, O2-100% on room air, and Temp-39.2oC (102.5oF). Physical examination reveals a lethargic infant with decreased motor tone and a full, bulging frontal fontanelle. What is the most important diagnostic study to obtain and what is the empiric treatment of choice while awaiting results?



Answer

  1. A full or bulging fontenelle is suggestive of meningeal edema and swelling are concerning for meningitis. Couple this with the lethargy and poor motor tone and this infant bought herself a lumbar puncture.
  2. Now….because of her age (<30 days old), you have to cover for a specific set of pathogens due to a developing immune system. Classically, neonatal sepsis bugs include group B streptococcus (GBS), Escherichia coli, and Listeria monocytogenes. Empiric antibiotic coverage (until gram stain results) is:
    1. Ampicilin (GBS)
    2. Gentamycin (gram negative coverage)
    3. Cefotaxime (wider gram negative coverage)
2004 – IDSA Guidelines

Ep-PAINE-nym



Bell’s Palsy

 

Other Known Aliases – facial nerve palsy, cranial nerve VII palsy

 

Definitionparalysis of cranial nerve VII that can can effect both motor and sensory function

Bellspalsy.JPG

Clinical SignificanceThis condition affects up to 20 patients per 100,000 population with no gender, race, or geographic predilection.  It is the most common cause of unilateral acute peripheral nerve palsies.  Although benign in clinical course, providers must pay close attention to differentiate between Bell’s palsy and a supranuclear lesion (stroke).  The most significant clinical difference between these two condition is the ability to raise the eyebrow and wrinkle the forehead.

https://pamadaydotnet.files.wordpress.com/2018/05/picture15.png

History – Named after Sir Charles Bell (1774-1842), a Scottish surgeon, anatomist, physiologist, neurologist, and noted philosophical theologian who received his medical doctorate at the University of Edinburgh in 1799.  While still a student, he illustrated and published an extraordinary textbook entitled “A System of Dissection Explaining the Anatomy of the Human Body”  After graduation, he was admitted and enrolled at The Royal College of Surgeons where he proved himself to be as skilled in surgery as in anatomy. He further published two subsequent volumes of “Anatomy of the Human Body”, with his brother John (also a skilled anatomist and surgeon).  He was such a prolific teacher and professor that the faculty at the University of Edinburgh blocked his advancement and he was forced to move to London where he first opened a private school of anatomy and then took over the Great Windmill Street School of Anatomy (founded by William and John Hunter).  In 1811, he published “An Idea of a New Anatomy of the Brain” considered to be the quintessential textbook of neurology.  In 1821, he published a paper entitled ” On The Nerves: Giving an Account of some Experiments on Their Structure and Functions, which lead to a new arrangement of the systems” where he described the trajectory of the facial nerve and the unilateral facial paralysis that could result.  This paper is still considered one of the classics of neurology and led to the disease bearing his name.  In 1824, he became the first professor of anatomy and surgery of the College of Surgeons in London and was knighted by King William IV due to his contributions of the advancement of medicine. 

 

Photograph of Sir Charles Bell


References

  1. Firkin BG and Whitwirth JA.  Dictionary of Medical Eponyms. 2nd ed.  New York, NY; Parthenon Publishing Group. 1996.
  2. Bartolucci S, Forbis P.  Stedman’s Medical Eponyms.  2nd ed.  Baltimore, MD; LWW.  2005.
  3. Yee AJ, Pfiffner P. (2012).  Medical Eponyms (Version 1.4.2) [Mobile Application Software].  Retrieved http://itunes.apple.com.
  4. Whonamedit – dictionary of medical eponyms. http://www.whonamedit.com
  5. Up To Date. www.uptodate.com
  6. Bell C, Shaw A. Reprint of the “Idea of a New Anatomy of the Brain,” with Letters, &c. Journal of anatomy and physiology. 1868; 3(Pt 1):147-82. [pubmed]
  7. http://rstl.royalsocietypublishing.org/content/111/398.full.pdf+html