Decision Tools for the Emergency Trainee

For those of you that missed out, we went through a quiz – family feud style, taking through some decision aids that can be useful and some that are not so useful. See the Prezi for the full competition, how many points can you score?

Importantly as you gain more experience you will find your clinical accumen/gestalt is on par with these decision rules but it does form a basis for which to teach and show junior staff what the major signs or risk factors for different conditions are. Also legally this may help you defend your choices for disposition and follow up.


Good decision tools:

Canadian CT Head


Canadian C-spine


WELLs Score PE


ADAPT Protocol


ABC Massive Transfusion



Scoring systems – word download with working links

Less helpful tools and why:

  • ABCD2 score for TIA, used in GP practice to predict stroke risk but was later proven to be inaccurate in the ED setting
  • King’s college criteria for paracetamol liver toxicity on deciding who needs a transplant – https://lifeinthefastlane.com/ccc/liver-transplantation-for-paracetamol-toxicity/
    • Data from Melbourne over 12 years: 40 patients with paracetamol induced fulminant hepatic failure (FHF)
    • Often no donor available for many days, so early transplantation less likely than at King’s in London
    • 2 deaths – 1/38 non-transplanted patients, 1/2 transplanted patients
    • Compared to the King’s data from Bernal et al (2002) survival of non-transplanted patients was 68%, compared to 19% at King’s
    • Rule out rule, in my mind I wouldn’t apply – if a patient presents with any of these symptoms we are likely to do a work up.
    • Unstructured judgment had sensitivity equal to that of the OSR and an equivalent specificity of 15.7%.Ottawa SAH rule: is positive if you are age >40, have neck pain, LOC, onset during exertion, thunderclap headache or limited neck movement.
    • https://emcrit.org/emnerd/the-adventure-of-the-three-students/ 
  • qSOFA – Tells us that sick people need ICU, reconfirms what we should be doing anyway, limited as a screen tool.
  • LRINEC for Necrotising Fasciitis  – which basically states if your worried still investigate + treat.
  • Ottawa Knee and ankle rules:
    • Sensitivities for the Ottawa ankle rule range from the high 90%-100% range for “clinically significant” ankle and midfoot fractures. This is defined as a fracture or an avulsion greater than 3 mm (i.e. you will miss some Weber A fractures with this rule)
    • Numerous studies found sensitivities for the Ottawa Knee Rules of 98-100% for clinically significant knee fractures. One study did find a sensitivity of just 86%.
  • Fisher scale for SAH: Only for risk of vasospasm:
    • Higher Fisher scale grades do not necessarily correlate with increasing probability of vasospasm. Studies show little to no difference between grades 1 and 2 (Claassen 2001), and that grade 4 is associated with a lower rate of clinical vasospasm than grade 3 (Fisher1980 & 1983Smith 2005Frontera 2006Kramer 2008).
  • The Hunt-Hess classification system was originally intended to help determine the risk of surgical mortality in patients admitted with
    • Higher grades, which are reflective of progressively higher hemorrhage severity and neurological dysfunction, are associated with higher overall mortality.
    • The scale was originally measured at admission and is typically used this way. Because it is purely clinical, the scale can change (for better or worse) during a patient’s hospital course.
    • Each grade corresponds to a specific set of clinical examination findings from 3 areas (level of arousal, reflexes, and meningeal irritation); a patient may present with a different combination of findings than that dictated by a given Hunt-Hess grade. Clinical judgment should be used to determine the final grade in these cases. (Rosen 2005)
  • San Francisco Syncope Score
    • This rule has a 96% sensitivity and 62% specificity for serious outcome – negative predictive value: 99.2%; positive predictive value 24.8%. However, an external validation at the Albert Einstein College of Medicine showed a lower sensitivity of 74%.
    • Serious outcome in this study is defined as “death, myocardial infarction, arrhythmia, pulmonary embolism, stroke, subarachnoid hemorrhage, significant hemorrhage, or any condition causing a return ED visit and hospitalization for a related event.” – I’m not sure a return visit to ED necessarily means I am concerned but it is interesting to note that in patients over the age of 40 with recurrent unexplained syncope = 50% is cardiac.
    • SFSS = Hct<30%, SBP<90, Tachycardia, heart failure, SOB, abnormal ECG.
  • What do you think the Kawasaki score comprises of?
  • Centor criteria for Strep Throat:
    • New 2012 Guidelines from the IDSA no longer recommend empiric treatment for patients alone; they recommend testing patients that are at higher risk for strep pharyngitis, but not giving antibiotics until a rapid test is positive or a throat culture is positive. (Not done in high risk communities like Pacifica populations or Torres Strait etc)
    • Evidence for preventing RF and subsequent rheumatic heart disease (RHD) comes from a series of studies performed in the 1950’s at the Warren Air Force Base. In this military population, investigators found that 2% of patients with strep throat developed RF. With antibiotics, this rate fell to 1% giving an absolute risk reduction of 1% and an NNT of 50-60 to prevent RF (Denny 1950,Wannamaker 1951Chamovitz 1954Siegel 1961). The work done by these researchers forms the basis for treatment over the last five decades.
    • However, we must ask the question of whether these studies apply to our patients today. The rate of RHD in the westernized world is exquisitely low. In fact, the CDC stopped tracking the incidence in 1995 when it fell below 1 per million. Numerous RCTs in developed countries have shown no cases of RF or RHD in patients treated with placebo (Middleton 1988,De Meyere 1992Dagnelie 1996Little 1997Zwart 2003). Also once over the aged of 30 step throat causing rheumatic heart disease is practically unheard of.
    • http://rebelem.com/patients-strep-throat-need-treated-antibiotics/