#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]

Ep-PAINE-nym



Jefferson Fracture

Other Known Aliasesnone

Definitionburst fracture of C1 that results in a multi-part fracture of the anterior and posterior arches.

Clinical Significance the most common mechanism of injury for Jefferson fractures is direct axial loading or hyperextension seen in diving injuries or falls. Most are unstable and require emergency stabilization via traction or halo placement while awaiting surgery.

HistoryNamed after Sir Geoffrey Jefferson (1886-1961), who was a British neurologist and pioneering neurosurgeon, and received his medical doctorate from the University of Manchester in 1909. He had prolific career as a pioneering neurosurgeon in Manchester throughout the 1920s-30s culminating in performing the first surgical embolectomy in England in 1925 and becoming the first professor of neurosurgery at the University of Manchester in 1939. He published the description of his eponymous injuries in 1920 describing a series of four cases of similar injuries. Side note: He was also an advocate for advancements in surgical science and gave a ground-breaking lecture at the Royal College of Surgeons in 1949 entitled “The Mind of the Mechanical Man”, where he discussed one of the earliest electronic computers at Manchester and laid the foundation for the debate on artificial intelligence.


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. Sir Geoffrey Jefferson 1886-1961. JNS. 1961;18(3):407-408. [article]
  7. Jefferson G. Fracture of the atlas vertebra. Report of four cases, and a review of those previously recorded. BJS. 1919;7(27):407-422. [article]

PAINE #PANCE Pearl – Orthopaedics



Question

11yo male presents to pediatrician with a 3 week history of a painful left hip. He and his parents denies any inciting or traumatic event and he denies fever, chills, recent illness, or past symptoms. On physical examination, he has a noticeable limp and you elicit pain with passive internal rotation of the hip. Radiograph is below.

  1. What is the main risk factor for this condition?
  2. What radiographic abnormality is seen?
  3. What is the management of this condition?
  4. What is the most serious adverse event associated with this condition?

Answer

Diagnosis – Slipped Capital Femoral Epiphysis

1. The main risk factor is obesity in adolescence with > 60% of cases occurring in children ≥90th percentile weight for age.

2. Diagnosing SCFE on plain radiographs is accomplished by drawing a parallel line from the lateral femoral neck towards the femoral head. This line is called Klein’s Line. In normal patients, this line should intersect the lateral portion of the femoral head. In SCFE patient, it does not.

3. The mainstay of management of SCFE is operative stabilization by way of percutaneous in situ fixation

4. The most serious complication seen with SCFE is avascular necrosis of the femoral head, but other complications include chondrolysis and femoroacetabular impingement.



References

  1. Loder RT. The demographics of slipped capital femoral epiphysis. An international multicenter study. Clinical orthopaedics and related research. 1996; [pubmed]
  2. https://www.orthobullets.com/pediatrics/4040/slipped-capital-femoral-epiphysis-scfe
  3. http://www.wheelessonline.com/ortho/treatment_scfe

Ep-PAINE-nym



Klein’s Lines

Other Known AliasesLine of Klein

DefinitionVirtual line drawn parallel from the femoral neck that should intersect the lateral upper edge of the femoral head

Clinical Significance Used in the radiographical diagnosis of slipped capital femoral epiphysis and allows for early diagnosis and surgical management to prevent avascular necrosis as an adult. The sensitivity and specificity are the highest if modified by a ≥2mm difference in the epiphyseal width lateral to Klein’s line compared to the unaffected side.

HistoryNamed after Armin Klein (1892-1954), who was an American orthopaedic surgeon and received his medical doctorate from Harvard Medical School in 1927. He completed his residency at Boston City Hospital and upon completion joined the faculty at Massachusetts General Hospital. It was here in 1952 that Klein and three colleagues published a case series on children with previously undiagnosed SCFE, but with positive findings using his technique. He would later go on to become Chief of Orthopaedic Surgery at the new Beth Israel Hospital in Boston and obtained teaching positions at Harvard Medical School and Tufts College Medical School.


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. KLEIN A, JOPLIN RJ, REIDY JA, HANELIN J. Slipped capital femoral epiphysis; early diagnosis and treatment facilitated by normal roentgenograms. The Journal of bone and joint surgery. American volume. 1952; 34-A(1):233-9. [pubmed]
  7. https://journals.lww.com/jbjsjournal/Citation/1954/36040/ARMIN_KLEIN_1892_1954.29.aspx

PAINE #PANCE Pearl – Orthopaedics



Question

11yo male presents to pediatrician with a 3 week history of a painful left hip. He and his parents denies any inciting or traumatic event and he denies fever, chills, recent illness, or past symptoms. On physical examination, he has a noticeable limp and you elicit pain with passive internal rotation of the hip. Radiograph is below.

  1. What is the main risk factor for this condition?
  2. What radiographic abnormality is seen?
  3. What is the management of this condition?
  4. What is the most serious adverse event associated with this condition?

Ep-PAINE-nym



Sjögren’s Syndrome

Other Known AliasesGougerot’s syndrome

Definitionchronic autoimmune inflammatory disease characterized by diminished lacrimal and salivary gland function

Clinical Significance Patients affected by this disease have dry eyes, dry mouth, dry skin, and various other systemic abnormalities. The exact mechanism is unknown, but is believed to be a combination of genetics (HLA association) and environmental triggers (viral pathogens).

HistoryNamed after Henrik Samuel Conrad Sjögren (1899-1986), who was a Swedish ophthalmologist who received his medical doctorate from the Karolinksa Institutet in 1922. He married a classmate of his (Maria Hellgren), who also happened to be the daughter of one of the most prominent ophthalmologists in Stockholm. He first encountered his future eponymous disease in 1925, and published a case report of five patients in 1930. He completed his doctoral thesis in 1993 on “Zur Kenntnis der keratoconjunctivitis sicca”, but unfortunately did not earn him the title of docent to pursue a career in academia. He did however enjoy a prolific career with numerous honorific appointments…..including docent at the University of Göteborg in 1961.


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. https://hekint.org/2018/09/11/henrik-sjogren-and-his-syndrome/
  7. Sjögren H. Zur Kenntnis der keratoconjunctivitis sicca. Keratitis filiformis bei Hypofunktion der Tränendrüsen. Acta Ophthalmol. 1933;2:1–151
  8. Murube J. Henrik Sjögren, 1899-1986. The ocular surface. 2010; 8(1):2-7. [pubmed]

PAINE #PANCE Pearl – Orthopaedics



Question

31yo male was involved in a pedestrian vs car accident and presents as a trauma transfer to your facility 3 hours after the injury. On initial presentation, the patient is in extreme distress and pain. Physical examination shows decreased dorsalis pedis and posterior tibial pulses, significant swelling, decreased sensation in the lower leg, and increased pain with passive dorsiflexion. Radiograph reveals a minimally displaced proximal tibia and fibula fracture.

  1. What is your main concern at this point?
  2. How do you test for it?
  3. What do you do about it?

Answer

  • The main concern given the mechanism of injury and physical examination findings is compartment syndrome. This is a limb-threatening condition and needs to be acted upon immediately.
    • The hallmark findings of compartment syndrome are:
      • Pain
        • Out of proportion
        • With passive stretching of muscles
      • Paralysis
      • Pulselessness
      • Paresthesias
      • Pallor
      • Poikilothermia
  • Testing for compartment syndrome involves directly measuring the pressure within the compartment. Commercial devices (such as Stryker) are common, but simple 18g needles attached to arterial line pressure monitors can also be used.
    • Normal pressure of tissue compartments should be < 10 mmHg.
    • Delta pressure = DBP – measured compartment pressure
      • Delta pressure < 30 indicates need for fasciotomy
    • Measuring of pressures SHOULD NOT delay transfer or consultation
  • Management of compartment syndrome is to perform a 4-compartment fasciotomy
    • Double-incision technique is most common to release all four compartments
      • Lateral incision – between fibular shaft and crest of tibia
      • Medial incision – 2cm medial to tibial margin


References

  1. Olson SA, Glasgow RR. Acute compartment syndrome in lower extremity musculoskeletal trauma. The Journal of the American Academy of Orthopaedic Surgeons. 2005; 13(7):436-44. [pubmed]
  2. Shadgan B, Menon M, O’Brien PJ, Reid WD. Diagnostic techniques in acute compartment syndrome of the leg. Journal of orthopaedic trauma. 2008; 22(8):581-7. [pubmed]Olson SA, Glasgow RR. Acute compartment syndrome in lower extremity musculoskeletal trauma. The Journal of the American Academy of Orthopaedic Surgeons. 2005; 13(7):436-44. [pubmed]
  3. Hammerberg EM, Whitesides TE, Seiler JG. The reliability of measurement of tissue pressure in compartment syndrome. Journal of orthopaedic trauma. 2012; 26(1):24-31; discussion 32. [pubmed]
  4. Nelson JA. Compartment pressure measurements have poor specificity for compartment syndrome in the traumatized limb. The Journal of emergency medicine. 2013; 44(5):1039-44. [pubmed]
  5. Fasciotomy. Wheeless’ Textbook of Orthopaedics. http://www.wheelessonline.com/ortho/12806