>EM Reflections – November 2017

Thanks to Dr Paul Page for leading the discussion this month

Edited by Dr David Lewis 

Top tips from this month’s rounds:

  1. Managing violent behaviour in the Emergency Department

  2. Early CT can miss delayed onset subdural hematoma after head trauma

  3. Posterior shoulder dislocation can be missed if not specifically ruled out



Managing violent behaviour in the Emergency Department

Workplace violence is unfortunately a common problem for Emergency Department staff.

Violence in the ED Reaches a Crisis Point

Not only is the environment high risk for exacerbating behavioural extremes but there are also a wide range of medical and psychiatric conditions that may present with violence and aggression.

Causes and associations with violence and aggressive behaviour in the ED:


  • Hypoxia
  • Hypoglycemia
  • Hypothermia
  • Metabolic
    • Pancreatitis, hepatic encephalopathy, hyponatremia, etc
  • Sepsis
    • UTI, meningitis, encephalitis, pneumonia, etc
  • Toxic
    • Alcohol, drugs, etc
  • Seizure, post ictal
  • Stroke
  • Dementia
  • Brain tumour
  • Head injury


  • Schizophrenia
  • Bipolar
  • Panic disorder, antisocial personality disorder, mood disorder, etc


  • Overcrowding
  • Police custody, gang violence, etc


Excellent article on managing behavioural emergencies in the emergency dept from LitFL:

Behavioural Emergencies



The CMPA provides medicolegal guidance on the use of restraint:

When there’s a possibility that patients may harm themselves or others, physical or chemical restraint may be required.

When using restraints physicians should consider the following risk management measures, which are based on the experts’ opinions in the analyzed CMPA cases:

  • Attempt to de-escalate the situation using other methods.
  • Obtain an adequate history, including medications and co-morbidities.
  • Conduct an appropriate physical examination.
  • Explain the plan for the use of restraints calmly and clearly to patients or substitute decision-makers.
  • Document the rationale for using restraints and use the least restrictive means necessary.
  • Ensure clear and readily available policies and procedures for monitoring restrained patients and ensure appropriate training of staff.
  • Adhere to applicable regulations, laws, and accreditation standards.


The National Institute of Clinical Excellence (NICE UK) provides guidance on the use of rapid tranquillisation:

Download (PDF, 62KB)


More Information and lInks:

Horizon Health Work Place Violence Prevention Policy: HHN-SA-012

ACEP – Emergency Department Violence Fact Sheet

Augusta University – Violence in ED Manual – violenceinedmanual


Reliability of Early CT in Head Injury

Modern CT is highly sensitive in the diagnosis of traumatic brain injury, including subdural and epidural hematoma following head trauma.



The medical literature contains reports of false negative early CT following minor head injury, however in this review, they were rare (3 adverse outcomes in 65,000 cases), hence their recommendation:


The strongest scientific evidence available at this time would suggest that a CT strategy is a safe way to triage patients for admission.


Case reports of delayed diagnosis of subdural / epidural hematoma following normal CT scan 




In patients who present, following head trauma, with persistent symptoms despite initially normal head CT, repeat imaging with MRI is recommended.

Symptoms of subdural hematoma

  • slurred speech.
  • loss of consciousness or coma.
  • seizures.
  • numbness.
  • severe headaches.
  • weakness.
  • visual problems.



Posterior shoulder dislocation can be missed if not specifically ruled out


Posterior shoulder dislocation is less common than anterior dislocation. It is a commonly missed diagnosis in the Emergency Department. It can occur following trauma and should be specifically considered following seizure / electric shock.

The patient present with shoulder pain and reduced range of movement. The shoulder / arm is adducted and internally rotated.

A single AP shoulder radiograph is unreliable, but may show the ‘lightbulb sign’. The axillary lateral is usually diagnostic but may be not be possible due to pain.

Posterior shoulder dislocation should be considered in all patients where the axillary lateral was impossible to perform due to pain and immobility. A scapular Y view should be performed


AP Shoulder – Lightbulb sign – posterior dislocation – due to internally rotated humeral head


AP Shoulder – posterior dislocation (more subtle appearance) – malalignment of joint line



Axillary view – posterior dislocation


Scapular Y view – posterior dislocation


Point of Care Ultrasound

Ultrasound can be very useful for diagnosing shoulder dislocation and can be performed quickly prior to formal radiography. The transducer is placed in a transverse orientation, posteriorly, just below the scapular spine. Move laterally to the joint.





In comparison to radiography, US had a sensitivity of 100.0%, specificity of 80.0%, positive predictive value of 98.7%, and negative predictive value of 100.0% in diagnosis of shoulder dislocation. The specificity of US in diagnosis of proper reduction of the joint, was estimated to be 98.7% with a negative predictive value of 100.0%. US took a significantly less time than radiography to be performed (p < 0.001).






EM Reflections - Nov 17 - CME Quiz

EM Reflections – Nov 17 – CME Quiz


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