Emergency Medicine

Question 1

NORMAL anion gap metabolic acidosis cause

Answer 1

Causes (ABCD)

Addisons (adrenal insufficiency)

Bicarbonate loss (GI or renal)

Chloride excess

Diuretics (acetazolamide)

Question 2

High anion gap metabolic acidosis causes

Answer 2

Causes (LTKR): lactate, toxin, ketones, renal

CO2

Alcoholic ketoacidosis, starvation ketoacidosis

Toxins

Metformin, methanol

Ureamia

Diabetic ketoacidosis

Paracetamol

Iron, isonioazid

Lactic acidosis

Ethylene glycol

Salicylates

Question 3

What is the ONE circumstance when it is appropriate to give 3 stacked shocks for resuscitation?

Answer 3

When a patient with a perfusing rhythm

• Develops a shockable rhythm
• In a witnessed and monitored setting (e.g. monitor attached)
• Defibrillator is immediately available
• They were previously well perfused and oxygenated pre-arrest

Question 4

Do you give a synchronous or asynchronous shock for VF/VT?

Answer 4

ASYNCHRONOUS

• Synchronous shocks are timed with the QRS complex, in VF/VT you dont have a QRS complex!

Question 5

What are the 4H’s + 4T’s?

Answer 5

4H’s

• Hypoxia (most common cause)
• Hyperkalaemia/hypokalaemia / metabolic
• Hypotension / hypovolaemia
• Hypothermia

4T’s

• Tension pneumothorax
• Tamponade
• Thromboembolic (pulmonary / cardiac)
• Toxic substances (e.g. TCA’s can cause VF)

Question 6

What is commotio cordis?

Answer 6

• Sudden death due to VF which may occur when a projectile strikes the precordium of an individual with no underlying cardiac disease.
• One of the leading causes of sudden cardiac death in young athletes
  
  • Exceeded only by: HCM, congenital coronary artery abnormalities
• Need to start CPR immediately!
• VF occurs when the impact is delivered 10-30ms before the T wave peak
• VF is NOT preceeded by VT

Question 7

What is catecholaminergic polymorphic VT?

Answer 7

• Inherited channelopathy, arrhythmogenic disease
  
  • 65% of causes Autosomal DOMINANT mutation in RyR2 receptor
• Episodic palpitations, syncope or cardiac arrest
• Precipitated by exercise or acute emotion
• Onset during childhood (mean age: 7-9 years)
• Family history of sudden cardiac death
• Ventricular arrhythmias reproducible on exercise stress testing
• Flick into VT when increased catecholamines (exercise, stress, excitement etc)

Features which should raise suspicion

• Previously well
• Cardiac arrest occurred during a physical activity or with excitement
• ECG shows frequent ventricular ectopics (usually multimorphic)
• VE’s become MORE frequent (or join to form VT) with adrenaline + become LESS frequent with opiates + anaesthetic
• Bidirectional VT (where ventricular complex QRS axis alternate by 180) is virtually pathognomonic when seen but is not needed for the diagnosis (also digoxin toxicity)

Question 8

What is the treatment of catecholaminergic polymorphic VT?

Answer 8

• AVOID adrenaline + catecholamines
• Administer general anaesthetic
• IV opiates
  
  • Fentanyl HIGH dose
• Hypotension + low cardiac output can be difficult to manage because catecholamines should be avoided. ECMO may be required
• Adjuncts for rhythm control = flecainide + beta blockers

Question 9

What are the common inherited channelopathies?

Answer 9

• Long QT
• Short QT
• Brugada
• Early repolarisation syndrome
• CPVT

Question 10

What are the airway adjunct measurement for

• ETT uncuffed
• ETT cuffed
• ETT measurement at the lip
• ETT measurement at the nose

Answer 10

• ETT uncuffed: [age (yr) / 4] + 4
• ETT cuffed: [age (yr) / 4] + 3
• ETT measurement at the lip: [age (yr) / 2] + 12
  
  • OR ETT size x 3
• ETT measurement at the nose: : [age (yr) / 2] + 15

Question 11

How many joules do you deliver for a defibrilattor shock?

Answer 11

• Manual defibrillator = 4J/kg
• AED paediatric (50J) = 1-8 yrs
• AED adult (100J) = >8 yrs

Question 12

What is an eschar?

Answer 12

A slough or piece of dead, necrotic tissue that is cast off from the surface of the skin. Seen in; burns, gangrene, ulcers, fungal infections, anthrax exposure, necrotizing spider/tick bites

Risk of bleeding highest 2-3 weeks

Question 13

A 2yr old girl presents to ED with a GCS of 15, RIGHT superficial parietal haematoma. Faily to be co-operative for CT scan + needs sedation. Which of the following is contraindicated because of the long half life?

• IV ketamine
• IV propofol
• Oral midazolam
• Oral chloryl hydrate
• Inhalant seroflourane

Answer 13

• IV ketamine 2-3 hours (peak 1 min)
• IV propofol 30-60 min
• Oral midazolam 2-4 hours
• Oral chloryl hydrate 8-10 hours
• Inhalant seroflourane minutes

Question 14

Which side effects are associated with ketamine?

Answer 14

• Tachycardia
• Bronchodilation (therefore good sedation for asthmatics)
• Hypertension
• Laryngospasm
• Vomiting
• Hypersalivation
• Nightmares
• Emergent reactions

Question 15

Does propofol have any analgesia effect?

Answer 15

NO

Causes CVS + respiratory depression

Question 16

What are the contraindications to the use of nitrous oxide?

Answer 16

• Pneumothorax
• Bowel obstruction
• Severe head injuries (potential for pneumocranium)
• Intoxication / depression conscious level
• Pregnancy
• Requiring >50% O2

Question 18

What are the symptoms of ibuprofen overdose?

Answer 18

Most children who ingest ibuprofen are asymptomatic, especially if the ingested dose is ≤100 mg/kg (10x normal dose).

When symptoms do occur, they usually present within four hours of ingestion and include nausea, vomiting, headache, drowsiness, blurred vision, tinnitus, ataxia, and dizziness. Life-threatening toxicity is rare and typically occurs at ingested doses over 400 mg/kg.

Life-threatening toxicity is rare and usually occurs at ingested doses >400 mg/kg. Features of life-threatening poisoning include apnea, bradycardia, hypotension, anion gap metabolic acidosis, polyuria with renal failure, coma, and/or seizures.