Emergency Medicine Flashcards
Neuroepileptic Malignant Syndrome
Caused by medications that block dopamine transmission, e.g. risperidone.
Fever, rigidity, mental status changes, and autonomic instability.
Severe rigidity: profound creatine kinase (CK) elevation.
Medication overdose causing wide QRS?
Tricyclic antidepressants e.g. amitryptilline
Describe the algorithm for VF/ pulseless VT
CPR - shock (4J/kg) - 2 min CPR - shock + adrenaline (after 2nd shock and then every 2nd shock i.e. 2,4,6,8) - 2 min CPR - shock + amiodarone (after 3rd shock)
Note: in non-shockable arrest (PEA/asystole), adrenaline is given immediately, and then every 2nd loop i.e. 1,3,5,7,9
Re-commence CPR after every shock, then assess rhythm after next 2 minutes i.e. if revert to sinus rhythm after shock, still need to give further 2 min CPR (as myocardial muscle is in refractory state and can easily revert back to VF) - don’t need to do this is signs of life are present
If the onset of VF/pulseless VT is witnessed on an ECG monitor then what is the next step?
- Defibrillation (asynchronous shock) should be attempted before any other treatment. However, if unmonitored, or unable to get defib within 30 seconds then start CPR
- Don’t use precordial thump (usually for sudden VF) in children
When might you use 3 shocks?
- Where a patient with a perfusing rhythm suddenly develops a shockable rhythm in a witnessed and monitored setting, defib is immediately available, and they were previously well perfused and oxygenated pre-arrest.
- Should not take >30 seconds to deliver all 3 shocks
What are the CPR ratios for: newborn, child, adult, lay person
- Newborn 3:1
- Child 15:2
- Adult 30:2
- Lay person 30:2
After the initiation of CPR, when do the coronary arteries start perfusing?
After the 5th compression (aortic pressure increases, RA pressure stays the same)
What are the 4 Hs + Ts of cardiac arrest?
- Hypoxia, hypovolaemia hypo/hyperkalaemia, hypothermia
- Thrombosis, tension pneumothorax, tamponade, toxins
What are the main causes of asystolic arrest?
Hypoxia and hypovolaemia
What are the main causes of PEA (rare, usually go into asystole)?
Hypovolaemia, hyper/hypokalemia, tamponade, thrombosis
What are the main causes of VF?
Hypothermia/hyperthermia, toxins (TCA poisoning), underlying cardiac disease
What is the dose of adrenaline for anaphylaxis?
0.01ml/kg of 1:1000 IM adrenaline (IV = 0.1ml/kg of 1:10,000)
= 10mcg/kg
(always count 5 x zeros)
What is the most common cardiac cause of sudden collapse?
Dilated cardiomyopathy
What are the causes of sudden, unexplained cardiac death?
- Congenital - hypertrophic CM, long QT, WPW, Brugada, Marfans, congenital CA abnormalities
- Acquired - commotio cordis, drug abuse, myocarditis
- Either: dilated CM, restrictive CM
What is commotio cordis?
Sudden death due to VF may occur when a projectile strikes the precordium of an individual with no underlying cardiac disease. One of the leading cuases of sudden cardiac death in young athletes (exceeded only by HOCM).
What is the formula for:
- ETT size cuffed
- ETT size uncuffed
- ETT measurement at lip
- ETT measurement at nose
- age/4+3
- age/4+4
- ETT size x 3, age/2 + 12
- age/2 +15
What is the formula for estimating weight?
(age + 4) x 2
What is the dose for DC shock?
4J/kg
What is the management for a scaphoid fracture?
Short arm plaster with thumb spica
What injuries would you backslab?
- Non-displaced fractures, minor injuries, swelling, crsuh, open fracture.
- Risk of ischaemic contractures with full plasters (Volkmann’s ischaemic contracture) - should only be used for displaced fractures to maintain reduction
What are the clinical signs and managmeent of a scaphoid fracture?
- Pain on dorsiflexion of the wrist, tenderness in snuffbox, pain on gripping.
- Can have normal x-rays first few days - treat all with below elbow POP with thumb spica, remove if normal x-ray at 2 weeks
- Complications: avascular necrosis (of prox segment) and non-union
Describe the anatomy surrounding a supra-condylar fracture
- Above elbow = brachial artery, below elbow = radial and ulnar artery
- Median and radial nerves most likely affected (ulnar nerve runs posterior to elbow joint)
Describe the nerve innervation of the hand
- Radial nerve - posterior thumb, 2 + 3rd finger to level of PIPJ
- Ulnar nerve - ant and posterior 1/2 of 4th + 5th finer
- Median nerve - ant hand thumb to 1/2 of 4th finger, back of hand top of 2+3rd fingers
What nerve is injured in a wrist drop?
- Radial nerve palsy - supplies triceps + extensor muscles of the forearm
- From spooning, crutches, Saturday night palsy
What sign on x-ray is suspcious for a supracondylar fracture?
Posterior fat pad on x-ray indicates bleeding into joint capsule - sail sign - lifts fat pad upwards/becomes more visible. Anterior fat pad is normal.
What is a monteggia’s injury, and what is the management?
- Proximal ulnar fracture and radial head dislocation
- Refer to ortho - needs reduction
What is a galleazi injury, and what is the management?
- Distal radius fracture (at wrist) and ulnar dislocation
- Refer to ortho
What is the order of ossification in the elbow joint?
CRITOE
- Capitellum
- Radial head
- Internal (medial) epicondyle (often avulsed in children)
- Trochlear
- Olecranon
- External (lateral) epicondyle
What is the normal retropharyngeal space appearance on lateral neck x-ray?
- At C2 <1/2 AP diameter of vertebral body
- At C6 < full width
Describe a hangman’s fracture
- Fracture C2 pedicles, ant subluxation C2 on C3
- Due to hyperextension of neck e.g. hitting face on windscreen in MVA
- Unstable fracture, risk of cord injury
What is a Jefferson fracture?
- Compression fracture of the bony ring of C1
- Unstable
- Due to diving into pool/blow to vertex head
Describe the Salter Harris Classification
1 - physis (through growth plate) 2 - physis + metaphysis (most common) 3 - physis + epiphysis 4 -physis + metaphysis + epiphysis 5 - crush of physis
80% are 1 or 2
3, 4, 5 - may result in growth disturbance as epiphysis is involved
Dsipalced 3 + 4 may require ORIF
SUFE appearance on x-ray?
Superior border of prox femoral epiphysis will lie on Klein’s line (line along femoral neck), when it should be higher
Describe Osgood-Schlatter’s disease
- Normal radiology
- Traction aphophysis
- Osteochondritis of tibial tubercle where patellar tendon inserts
- Painful, worse with activity and kneeling
Describe perthes disease
- Osteonecrosis of the femoral head due to ischaemia
- Abnormal moth-eaten femoral head
- Increased risk with thrombophilia, infection, trauma
- M>F, increased risk age 4-8y, bilat in 10%
- Pain groin, thigh, knee
- Tx: cast or surgery, maintain head in acetabulum
Describe osteoid osteoma
- Benign bone tumour
- X-ray: new bone formation, occassionally lucent spot
Osteomyelitis vs. septic arthritis
- OM: more vague history, consider if unexplained fever, irritability, assymetrical use of limb. Most commonly tibia and femur. X-ray abnormalities in 7-10 days
- Septic arthritis: may be vague history of trauma, surgerical emergency in hip (pus causes AVN), not usually associated with swelling or limb tenderness
What is an eschar and when does it bleed?
- Dead tissue, contains necrotic tissue, not the same as a scab (whcih has exudate)
- Seen in burns, gangrene, ulcer, spider bit wounds
- Risk of haemorrhage from eschar separation greatest at 2-3 weeks
What are the risks of lightening strike?
- Deafness (ruptured ear drum)
- Amnesia
- Prolonged QT
- Seizure
- Peripheral neuropathy (delayed)
What are the causes of fatality in burns?
- Early mortality due to fluid loss/dehydration
- Late mortality due to sepsis/infection
Describe the first aid management of burns
- Running water at room temp, around 18 degrees
- Effective for up to 3 hours post burn
- Cool for 20 min
- Don’t use icepack
- Stops progression in zone of stasis which leads to necrosis (zone of coagulation is central area, already damaged)
Describe the rule of 9s in paeds burns
- Head 18%
- Torso 18% front, 18% back
- Arms 9% each
- Legs 14% each
- Perineum 1%
What are the side effects of ketamine sedation?
- Laryngospasm and bronchodilation
- Tachycardia and hypertension
- Vomiting
- ? inc ICP
- Emergent reactions, like waking up from nightmare
- Good for analgesia and amnesia
What are the effects of midazolam for sedation?
- Amnesia, sedation, anti-anxiolytic, anticonvulsant
- Respiratory depression
- May cause paradoxical hyperactivity
- Atagonist: flumezanil
What sedative cuases chest wall rigidity?
Fentanyl
What are the contraindications to using entonox (nitrous oxide) for sedation?
- Gas-filled space (pneumothorax, bowel obstruction)
- Severe head injuries (risk of pneumocranium)
- Intoxication/depressed LOC
- If requiring >50% FiO2
- 1st trimester pregnancy
Presentation of pericarditis?
- Usually well, chest pain, recent viral illness
- Normal CXR heart and lungs
- May have friction rub (inflammation)
- May have fluid accummulation -> no rub, decr voltages on ECG, inc heart size on CXR
- If no fluid: ST segment elevations, T wave inversion
What are the complications of myocarditis?
- Inflammation of heart muscle/myocardium
- Cardiomegaly
- Increased pressures (LV, LA, PV, arterial)
- Pulmonary oedema and congestive heart failure
What are the causes of myocarditis?
- Usually viral: coxsackie A +B, adenovirus, CMV, echovirus, EBV
- Drug hypersensitivity
- Drug toxicity
- Immune-mediated: rheumatic fever, Kawasaki
What are the symptoms and signs of myocarditis?
- Non-specific malaise, fever, anorexia
- Dysrhythmias (AV conduction or junctional, tachy)
- Chest pain (due to ischaemia or pericarditis)
- Tachypnoea
- Decr cardiac output: tachycardia, weak pulses, cool periph, mottling
- Muffled HS, S3, AV valve regurgitation murmur
- Hepatomegaly, oedema, inc JVP
- Rash (viral illness)
What are the ECG findings in myocarditis?
- Low voltage QRS
- Pseudo-infarction: pathological Q waves, poor progression R waves
- TWI or flattening
- LVH
- Prolonged PR or QTc
- Arrythmias
Treatment of SVT?
- Vagal stimulation - ice to face, carotid sinus massage, valsalva
- Adenosine
- Synchronised DC cardioversion
What is the management of a button battery in the stomach?
If asymptomatic and in stomach, then can be allowed to pass. Follow up xray in 24-48 hours, if still in stomach then for endoscopic removal. Check for disruption of battery on x-ray (heavy metal poisoning)
What are the complications of Kawasaki Disease?
- Urethritis with sterile pyuria
- Hepatic dysfunction
- Arthritis or arthralgias
- Aseptic meningitis
- Pericardial effusion or arrythmias
- Hydrops of the gallbladder
Commonest cause of painless abdominal distension in a neonate?
Sepsis (would have vomiting with volvulus)
Describe the ligaments in malrotation?
- Ligament of Treitz is absent (by distal end of transverse colon)
- Ladd’s bands present (between caecum and duodenum, lead to midgut volvulus)
What is the mortality risk of measles encephalopathy?
15%
Risk factors, symptoms, and treatment for SUFE?
- Obesity, hypothyroidism, hypopituitary, renal osteodystrophy
- Vague acute or chronic groin/thigh/knee pain, may have sudden exacerbation, history of small trauma, limp and externally rotate leg
- Posterior and inferior displacement head compared to femoral neck
- Abnormal Klein’s line
- M>F, L>R, 11-16yo
- Tx: bed rest and pinning
- Risks: osteonecrosis
What is the mechanism of a pulled elbow, and how do you treat it?
- The annular ligament becomes trapped between
the radius and humerus - Stabilise radial head, supinate or pronate forearm, and flex elbow
Overdose with high anion gap metabolic acidosis?
- Methanol
- Ethylene glycol
- Salicylates
Anticholinergic toxidrome
- Tricyclic antidepressants (amitriptyline), antihistamines, atropine
- Mad hatter, blind bat, dry bone, hot hell, flushed beet
- Dilated pupils (non reactive), tachycardia, hypertension, tachypnoea
- Dry skin and mucous membranes
- Decr bowel sounds, ileus, urinary retention
- Myoclonus, choreoathetosis, picking/plucking at things
- Agitation, delirium, hallucinations
- ECG: prolonged QRS, arrhythmia
- Tx: sodium bicarbonate, physostigmine (acetylcholinesterase inhibitor)
Hallucinogenic/sympathomimetic toxidrome
- e.g. amphetamine, MDMA, LSD, ecstasy
- Dilated pupils (brisk reactive), tachycardia, hypertension, tachypnoea, sweaty, nystagmus
- Hallucination, agitation, depersonalisation, distorted perception
- Fear, panic, dysphoria
- Tx: calm environment, midazolam or haloperidol for agitation PRN
Opioid toxidrome
- Opioids e.g. morphine, methadone, heroin
- Miosis (small pupil)
- Drowsiness, coma, slurred speech, impaired attention
- Respiratory depression and bradycardia
- Euphoria, dysphoria, impaired judgement
- Can develop pulmonary oedema and dyspnoea
- Tx: naloxone
Sedative hypnotic toxidrome
- e.g. benzodiazepines, ethylene glycol, methanol, ethanol
- Dilated or small pupils
- Bradycardia, bradypnoea, hypotension, hyporeflexia
- Confusion and stupor
- Ethanol - slurred speech, unsteady, inappropriate behaviour
- Ethylene glycol - CN palsies and tetany
- Tx: flumazenil for benzo (not for chronic abuse as triggers seizures), fomepizole or ethanol for methanol/EG + urgent dialysis if high AN metabolic acidosis
- Tx (others): supportive, IVF for hypotension, benzo and haloperidol for sedation
Cholinergic toxidrome
- Organophosphates and insecticides, nerve agents, mushrooms
- Small pupils (miosis)
- SLUDGEBBB
- Lacrimation, salivation, urination, defecation, vomiting
- Bronchospasm, bradycardia, bronchorrhea
- Fasciculations, weakness, paralysis, seizures, coma
- Tx: atropine (competes with acetylcholine), pralidoxime (for fasciculations or weakness)
Serotonin syndrome
- e.g. SSRIs (fluoxetine), tramadol, amphetamines
- Dilated pupils, tachycardia, hypertension
- Hyperthermia
- Clonus and trismus, hypertonia, hyperreflexia
- Sweating, flushing, tremor, rigidity, diarrhoea
- Tx: supportive, diazepam if agitated, antidote is cyproheptadine (serotonin antagonist)
Salicylate intoxication
- e.g. aspirin
- Respiratory alkalosis followed by high anion gap metabolic acidosis
- Can be fatal >3g in children
- Tinnitus, vertigo, N and V
- Tachypnoea, hyperpnea
- Agitation, lethargy, hyperthermia >41, coma
- Pulmonary oedema or cerebral oedema
- Tx: glucose/dextrose (decr CSF glucose), IV sodium bicarbonate for alkalinisation, may need dialysis
What are the main effects seen in digoxin toxicity?
Hyperkalaemia (blocks Na-K ATPase) and arrhythmias (AV dissociation - 1st to 3rd degree heart block)
Carbon monoxide intoxication
- Headaches, confusion, vomiting, seizures, coma
- Tx: 100% O2, hyperbaric oxygen
- Neuropsych assessment 1-2 months
Neuro-epileptic malignant syndrome
- Idiosyncratic reaction to neuroleptic or antipsychotic drugs (4-14 post starting) - highest in haloperidol. Can also happen in olanzapine, quetiapine, metoclopramide
- Gradual onset, prolonged course
- Hyperthermia, sweating, unstable BP, stupor
- Diffuse rigidity (hypertonia)
- Reduced reflexes
- Normal pupils
- Tx: stop meds immediately, supportive, cooling, hydration
Management of unidentified ingestion
- Min 12 hrs observation
- Check BSL
- IV access if toxicity
- Monitor LOC, vital signs, BSL +/- cardiac monitoring
- Discharge only in daylight
What ECG changes do you see in tricyclic antidepressant overdose and how do you treat it?
- Prolonged QRS (normal QRS < 0.12sec)
- IV sodium bicarbonate
What is the antidote for B-blocker overdose?
Glucagon
What is the antidote for CCB overdose?
Calcium gluconate/chloride or high-dose insulin and glucose (calcium channel blockers block insulin release leading to hyperglycaemia)
What is the antidote for sulfonylurea (eg glipizide) overdose?
Octreotide (inhibitor of growth hormone, glucagon, and insulin, is like somatostatin)
What is the antidote for tricyclic antidepressant overdose?
Sodium bicarbonate
What is the antidote for isoniazid (anti-TB) overdose?
Pyridoxine
What is the antidote for iron overdose?
Desferroxime
What is the antidote for methaemoglobin overdose?
Methylene blue
What is the antidote for ethylene glycol overdose?
Fomepizole or ethanol
What is the antidote for benzodiazepine overdose?
Flumazenil
Beta-blocker or calcium channel-blocker overdose presentation
- Drowsiness, altered mental status
- Bradycardia, hypotension
- Normokalaemia (c.f. digoxin with hyperkalaemia)
- ECG: sinus brady, abnormal AV node conduction, accelerated junctional rhythm
- Tx: glucagon (BB) or calcium gluconate (CCB)
Discuss colchicine ingestion
- Heart sink ingestion
- Rapidly absorbed
- Gastro symptoms within 24 hours
- > 0.8mg/kg associated with 100% mortality
- No antidote, give activated charcoal
Activated charcoal is not useful (or is contraindicated) in which settings?
- Pesticides, petroleum
- Hydrocarbons, heavy metals >1hr since ingestion
- Acids, alkali, alcohol
- Iron
- Lithium
- Solvents
What are the causes, signs, and symptoms of neurogenic shock?
- Stimulation of parasympathetic, or inhibition or sympathetic
- Widespread vasodilation
- Bradycardia, hypotension, warm skin
- Causes: spinal cord injury above T5, spinal anaesthesia, vasomotor center depression (pain, drugs)
Discuss the movements for C4-S1 nerves
Shrug shoulders - C4 Flex elbow - C5 Pull wrist back - C6 Straighten arm - C7 Open and close fingers - C8 Spread fingers - T1 Flex hip - L1 and 2 Straighten knee - L3 Flex ankle up - L4 Push ankle down - L5, S1
Pulsating proptosis and cannot look down. Injury is…?
Superior wall orbital fracture
Cannot look away from the injury = superior
Treatment of head injury in Haemophilia A?
Give factor 8 to bring factor levels to 100%, even if no evidence of bruising or swelling
What are the cases of wound infections post human bite?
Staph aureus, strep, Eikenella corrodens
At what level of paracetamol ingestion would you be concerned?
> 200mg/kg or >10g total, based on ideal body weight
When do you check parecetamol levels
2hrs for elixir, will need repeat if equivocal
4hrs for tablets
If >8hrs then start NAC while awaiting paracetamol levels
Typical vs atypical antipsychotics
- Typical = haloperidol, chlorpromazine - can cause QT prolongation
- Atypical = olanzapine, risperidone (can cause acute dystonia)
What is the toxic dose for iron?
> 60mg/kg elemental iron
FFP vs cryoprecipitate
FFP contains all factors.
Cryoprecipitate contains fibrinogen, vWF, F8 + 13
What is the timing or primary, mixed, and permanaent dention?
- Primary 6m-6y, lower central are first, then upper central
- Mixed 6y - 12y
- Permanent >12y
What is a Bohn’s nodule?
Remnant of salivary gland located on buccal or lingual mucosa, or hard palate. No treatment needed. Epstein’s pearls = keratin nodules on palate
