A three-year-old boy is being resuscitated in the community following an immersion injury. What is the currently recommended ratio of external cardiac compressions to exhaled air resuscitations for a two rescuer resuscitation in this patient?
A 16-year-old girl is brought to the Emergency Department after attending a dance party. On presentation, she is extremely confused and agitated, she looks flushed and sweaty, and has dilated pupils. Her heart rate is 120 beats/minute and her blood pressure is 140/90 mmHg. She is complaining of some central chest pain.
Her presentation is most likely due to the ingestion of which of the following drugs?
A. Cannabis (Marijuana).
B. Diamorphine (Heroin).
C. Gamma Hydroxybutyrate (Grievous Bodily Harm, GHB).
D. Ketamine (Special K).
E. 3,4–Methylenedioxymethamphetamine (Ecstasy).
E. 3,4–Methylenedioxymethamphetamine (Ecstasy).
A ten-year-old girl is brought into the Emergency Department after being bitten by an unidentified snake. The snake venom detection kit is positive for brown snake venom from a bite site swab. Which of the following is the most common clinical effect in this envenomation?
A patient in the Emergency Department has the laboratory results shown below:
Serum Sodium 130 mmol/L [136 – 146 mmol/L]
Serum Potassium 6.5 mmol/L [3.5 – 5.0 mmol/L]
Serum HCO3 14 mmol/L [22 – 28 mmol/L]
Serum Chloride 115 mmol/L [95 – 107 mmol/L]
Venous pH 7.19 [7.34 – 7.44]
PCO2 42 mmHg [35 – 45 mmHg]
Base excess –10 mmol/L [-3 – + 3 mmol/L]
Which of the following is the most likely cause of the acidosis?
A. Acute renal failure.
B. Diabetic ketoacidosis.
C. Lactic acidosis.
D. Renal tubular acidosis.
E. Salicylate poisoning.
D. Renal tubular acidosis.
The distinguishing feature is the hyperchloremia.
Defect in renal tubules prevents reabsorbtion of all of the filtered bicarbonate or excretion of ammonium ions in the urine. RTA's characterised by hyperchloremic metabolic acidosis (so normal anion gap). Na+ and H2O are taken with the HCO3.
- T1 (distal) low because K+ excreted instead of H+ during Na+ reabsorption. Can also be high due to voltage defects and hypoaldosteronism.
- T2 (proximal) low because HCO3 takes Na+ and H2O causing volume depletion - stimulates aldosterone which exchange K+ for Na+ (reabsorbed) in distal tubule.
Pt has metabolic acidosis with normal CO2, and low HCO3. Cl- is elevated indicating RTA. K+is high. Anion gap is normal at 7.5 (normal =6-16)
In acute renal failure, ketoacidosis, lacticacidosis and salicylate poisoning the anion gap would be elevated and no hyperchloraemia. (think of MUDILES)
What is antidiuretic hormones action on the kidney?
Peptide released by posterior pituitary that promotes water reabsorption in collecting ducts.
Describe the renin-angiotensin system and its physiologic role.
Renin is released from the JGA in response to low volume/low Na+ detected at JGA.
Renin is the first step in the angiotensin II pathway.
Angiotensin II acts in three ways
2. Stimulates proximal Na+ reabsorption
3. Stimulates secretion of Aldosterone from adrenal cortex which stimulates Na+ reabsorption
In acute paracetamol overdose, which of the following mechanisms may result in hepatotoxicity?
A. Conversion by cytochrome P450.
B. Conversion to glutathione conjugate.
C. Conversion to sulphate conjugate.
D. Direct toxic effect of unchanged drug.
E. Metabolism to phosphate form.
A. Conversion by cytochrome P450
Paracetamol is metabolised in the liver to sulfate and glucoronide conjugates which are both non toxic and excreted in the urine. Of the remaining paracetamol, half is excreted unchanged in the urine. The remaining half is metabolized by cytochrome P450 to hepatotoxic NAPQI. At non toxic paracetamol doses, NAPQI is rapidly conjugated to hepatic glutathione (non toxic) and excreted in the urine. At toxic doses, the glutathione stores are depleted and hepatotoxic NAPQI accumulates.
How would you expect a child with transverse myelitis to present?
Motor and sensory deficitis involving one or both sides of spinal cord
paraesthesia (1st), weakness and sphincter dysfunction (urinary retention)
Often associated with severe back pain
May have partial recovery after 1-3 months.
- paraesthesia (1st), weakness and sphincter dysfunction (urinary retention)
In the following drugs used in the ED setting for sedation, what are the onset/offsets times of the drugs?
- PO midazolam
- chloral hydrate
- Inhaled serflourane
Ketamine - quick onset/offset
Propofol - usually used in adults, used in intubation for kids, short onset/offset
Midazolam - may not always sedate. Unreliable onset/offset times. Might be long time after dose given.
Chloral hydrate - onset variable, long offset
Inh seroflourane - quick onset/offset
What is mx of paracetamol OD?
If max possible dose <200mg/kg OR total ingested dose <10g - no levels or intervention needed.
If max possible dose ingested >200mg/kg OR >10g OR unknown dose
if tabs/capsules - measure levels at 4 hrs
if elixer - measure 2 hr level
<500mcg/L on graph - no action
>500mcg/L on graph - level at 4 hrs
Activated charcoal if
presents w/i 1 hr and
no co-ingestion likely to decrease LOC and
- if tabs/capsules - measure levels at 4 hrs
if elixer - measure 2 hr level
- <500mcg/L on graph - no action
- >500mcg/L on graph - level at 4 hrs
- presents w/i 1 hr and
- no co-ingestion likely to decrease LOC and
- Dose >200mg/kg
Salicylate poisoning - acidosis or alkalosis?
Respiratory alkalosis followed by metabolic acidosis.
(remember mudpiles- high anion gap acidosis)
What is anion gap likely to look like in ARF, DKA and lactic acidosis?
High anion gap.
Best imaging for bleeding suspicious of Meckels?
Management of pulseless VT in ED?
Shape of bleed of subdural haematoma?
Shape of extradural haematoma?
What is Mannitol used for?
What Rx for hypertensive emergency?
Investigation for bileous vomiting?
Barium meal to look for volvulus
Phases of iron overdose.
0-6 hrs - mucousal irritant. D & V, bleeding.
6-24 hours - seems well
Begins when acidotic. Cyanosed, coma, seizures, shock
Ix in iron overdose?
AXR - if present, tablets will be seen.
If few, whole bowel irrigation.
If many together, surgical removal.
Management of Iron overdose if symptomatic within 6 hours?
Symptoms of anticholingergic toxidrome?
Blind as a bat,
mad as a hatter,
red as a beet,
hot as a hare,
dry as a bone,
the bowel and bladder lose their tone,
and the heart runs alone
What NV structures affected by supracondylar #?
Median nerve and Brachial artery.
What do you test for to determine if unilateral nasal discharge is CSF leak?
Treatment of pulseless VF
What increases risk of invasive pneumococcal?
Age <2, >65
chronic CV, resp, liver disease, renal failure, nephrotic syndrome
immunocompromised for any reason
In the oxygen dissociation curve, a shift to the right decreases affinity for oxygen (easier to unload at tissues).
What conditions shift curve to right?
To right (decrease affinity)
- decreasing pH/more acidotic
- increasing temp
- increasing CO2
- increasing 2,3 DPG/2,3 BPG
To left (increase affinity)
- increasing pH
- carbon monoxide
NB. affinity of heme to CO is 230times that of oxygen so will preferentially bind CO. The other three of the the four tetramers bind O2 but affinity is so strong it won't release at tissues. This is how CO poisoning occurs.
Describe a subdural haemorrhage
Bleeding from rupture of bridging vessels between dura and arachnoid.
Crescent shaped on CT.
Crosses suture lines but limited by limited by dural attachments (falx cerebri and tentorium cerebelli)
Describe an extradural haemorrhage
Between dura and skull
Doesn't cross suture lines
describe a subarachnoid haemorrhage
Type of stroke
Bleeding into subarachnoid space
assoc c head injury or sudden "thunderclap" headache
Describe intracerebral haemorrhage
Haemorrhage within brain tissue caused by trauma or haemorrhagic stroke.
Describe intraventricular haemorrhage
Occurs in subependymal or germinal matrix
most frequent in
Other RF include prolonged resus, RDS, chorioamnionitis, no maternal glucocorticoids
Describe how CO exerts its toxic effects on inhalation
Reversible binding of CO to cytochrome A3.
CO binds to cytochrome oxidase disrupting cellular respiration. This is the toxic effects exerted.
CO binds to haemoglobin (carboxyhaemoglobin - COHb) and has >200 times the affinity of oxygen. Oxygen is displaced and there is impaired delivery to the cells. COHb does not correlate well with toxic effects.
CO displaces NO from protein (NO is potent vasodilator).
Treatment is high flow oxygen.
If levels >20%, consider intubation for 100% O2 to remove CO 200 times faster than room air.
Anion gap is calculated by
Mean anion gap is 8+/-2
What are the causes of a high anion gap metabolic acidosis?
Uraemia (renal failure),
Iron, isoniazid, inborn errors of metabolism,
When is sycope more likely to be of a cardiac nature?
Syncope is more likely to be of a cardiac nature in the following situations: – Syncopeduringexerciseorexertion
- Sudden onset without prodromal dizziness or awareness
- Complete loss of tone or awareness so that fall leads to injury
- History of preceding palpitations
- Significant tachycardia or bradycardia noted after the event
- Family history of sudden death
What is the main treatment for all forms of RTA?
What is the most common serious complication of etoh ingestion in a child?
Hypoglycemia due to impaired gluconeogenesis.
Infants have even less ability compensate for this with glycogenolysis due to decreased glycogen stores.
What is Human Metapneumavirus commonly associated with?
LRTIs ie Bronchiolitis
RSV is in metapneumavirus family
What is Erysipelas?
Erysipelas is a rare acute Group A
Streptococcus infection (aka S.pyogenes) involving the deeper layer of the skin and underlying connective tissue.
• Illness onset is abrupt and systemic symptoms are usually present. The most characteristic finding is a rash with a sharply defined slightly elevated border.
• Affected skin is swollen, red and very tender.
When is Whole Bowel Irrigation (WBI) indicated in iron overdose?
Whole bowel irrigation is the decontamination treatment of choice in iron poisoning (activated charcoal does not absorb iron). WBI is indicated in children with an abnormal x-ray or those who are currently symptomatic.
Describe Ramsay Hunt Syndrome
Ramsay Hunt syndrome (herpes zoster oticus with facial paralysis) may present with herpes vesicles in the ear canal and on the pinna, facial paralysis and pain. Other cranial nerves may be affected e.g. 8th nerve.
Treatment includes systemic antiviral agents e.g. acyclovir and corticosteroids
Up to 50% of patients with Ramsay-Hunt syndrome do not completely recover their facial nerve function.