Acute Care

Question 1

Anticholinergic poisoning

Answer 1

eg. oxybutynin, ipratropium

effects:

• increased HR/BP
• increased temperature
• dilated pupils
• decreased bowel sounds
• decreased diaphoresis

antidote: physostigmine (AchE inhibitor)

Question 2

Antidotes

Answer 2

Beta blocker: glucagon

Calcium channel blocker: glucagon, insulin

Ethylene glycol: fomipazole

Local anaesthetic: IV lipid emulsion

Iron: desferroximine

Methemoglobinaemia: methylene blue

Sulfonylureas: octreotide

TCA: sodium bicarbonate

Question 3

Burns

Answer 3

treatment: cooling: 20 mins at 15 degrees within first 3 hours

prognosis: cooling will not change zone of coagulation/stasis but will improve zone of hyperaemia

Question 4

Cholinergic poisoning

Answer 4

eg. organophosphate, ACh receptor agonist

effects:

• pupillary constriction
• increased bowel sounds
• diaphoresis

antidote: atropine

Question 5

Dexmedetomidine

Answer 5

mechanism: alpha 2 adrenoreceptor agonist

effect: sedation, analgesia, NO respiratory depression

use: sedation for intubated patient

side effects: HTN, bradycardia

Question 6

Ecstacy

Answer 6

class: sympathomimetic amphetamine

mechanism: presynaptic serotonin, noradrenaline, dopamine

symptoms:

• CVS: increased and decreased BP
• CNS: agitation, coma, convulsions, disinhibition
• Msk: ridigity, rhabdomyosis
• urinary failure
• cerebral oedema, hepatitis, hyperpyrexia, hyponatraemia

treatment: benzodiazepine, antihypertensive

Question 7

Ibuprofen

Answer 7

mechanism: proprionic acid derivative inhibits COX

effect: analgesic, antipyretic, antiinflammatory

half life: 2 hours

drug elimination: hepatic

SEs: GI

overdose: life threatening >400mg/kg, nausea, vomiting, drowsiness, blurred vision, dizziness

treatment OD: charcoal

• limited use in alkalinisation urine/diuresis as minimal renal excretion

Question 8

Ketamine

Answer 8

mechanism: NMDA antagonist blocking afferent impulses causing dissociation of the limbic system

effect: amnesia, analgesia

side effects: LARYNGOSPASM, HTN, tachycardia, vomiting, nightmares, increased ICP, increased bronchial secretions

Question 9

Lead poisoning

Answer 9

symptoms:

• decreased appetite, weight loss
• vomiting, abdominal pain
• constipation
• anaemia
• renal failure
• lethargy
• learning/behavioural issues

Question 10

Lignocaine

Answer 10

mechanism: blocks Na channels in peripheral nerves inhibiting depolarisation

Question 11

Midazolam

Answer 11

mechanism: potentiates inhibitory effects of GABA throughout the CNS

• SHORT duraiton

effect: anxiolytic, sedative, hypnotic, muscle relaxant, antiepileptic

side effects: apnoea, hypotension, decreased myocardial function

Question 12

Nitric oxide

Answer 12

mixture: entonox 50:50 oxygen and N₂0

CI: gas filled space (PTX, BO), severe head injuries, decreased GCS, pregnancy

adverse effects: vomiting 10%, dysphoria 1%

Question 13

Cholinergic toxidromes

Answer 13

*organophosphates inhibit AChE and produce muscurinic symptoms

• treatment with anticholinergic eg. atropine

Question 14

Propofol

Answer 14

mechanism: CNS depressant by GABA + blocking Na channels

use: induction of GA, NO ANALGESIA

side effects: bradycardia, hypotension, pain at IV site

Question 15

Sedative poisoning

Answer 15

eg. benzodiazapines, antihistamines

effect:

• bradycardia/hypotension
• bradypnoea
• hypothermia
• decreased bowel sounds
• decreased sweating

antidote: flumazenil

Question 16

Serotonin Syndrome

Answer 16

mechanism: serotonergic drugs

effects:

• anxiety/restlessness
• HTN/tachycardia
• hyperthermia
• myoclonus
  treatment: serotonergic antagonist eg. cyproheptadine

Question 17

Spinal shock

Answer 17

clinical: hypotension, bradycardia, warm skin

Question 18

Sympathomimetic poisoning

Answer 18

eg. adrenaline, cocaine

effect:

• increased HR/HTN
• tachypnoea
• hyperthermia
• pupillary dilation
• increased bowel sounds
• diaphoresis

antidote:

Question 19

TCA overdose

Answer 19

drug mechanism: therapeutic effect by SNRI and NET

• additionally potent antihistamine/anticholinergic

half life: 24 hours

symptoms overdose:

• anticholinergic: CNS (agitation, confusion, lethargy), tachycardia, dry mouth, mydriasis, fever, urinary retention, vomiting
• antiadrenergic: vasodilation
• Na channel blockade: wide QRS, long QT, arrythmias
• CNS depression: seizures, coma

diagnosis:

• ECG: prolonged PR, QRS, QT

treatment: IV sodium bicarb if wide QRS

Question 20

Wound infection

Answer 20

cat: Pasteurella multicoda

dogs: Streptobacillus moniliformis

human: Eikenella corrodens

Question 21

Gastric Foreign Bodies

Answer 21

• most will pass 4-6 days

conservative management EXCEPT:

• button batteries
• magnets
• objects longer 5cm or diameter 2.5cm

management: weekly radiographs

Question 22

Spinal injury

-fulcrum-

Answer 22

cervical mobility changes with age:

• <8yrs: C1-C3
• 8-12yrs: C3-C5
• >12yrs: C5-C6

Question 23

Spinal injury

-micturition-

Answer 23

pontine micturition centre: coordinates sacral centre

PSNS (S2-S4): innervates detrusor

SNS (T11-L2): innervates trigone/neck, proximal urethra

somatic NS (S2-S4): innervates muscles including external sphincter

Question 24

Spinal injury level

Answer 24

C1-3: ventilator dependent

C5: hand to mouth activities

C6: hand function

C7: independent ADLs

Question 25

Autonomic Dysreflexia

Answer 25

injury: C6 and above

pathogenesis: widespread reflex activaty of SNS triggered by ascending sensory stimulus

clinical:

• vasoconstriction, pallor, diaphoresis, goose bumps
• bradycardia, hypertension, headache, blurred vision

Question 26

Solution to dilution

Answer 26

1: 1000 = 1% = 1mg/ml
1: 10,000 = 0.1% = 0.1ml

Question 27

ETT Formula

Answer 27

ETT length from lips= age/2 + 12

ETT size= age/4 + 4mm

* Cuffed for >8 years

* Straight blade for <1 year

Question 28

Rapid Sequence Intubation

Answer 28

1st: Hypnotic agent:

• eg. thiopentone (3-5mg/kg), midazolam (0.5 mg/ kg) or propofol (2-4 mg/kg);

2nd Muscle relaxant:

• eg. suxamethonium (1 mg/kg), rocuronium (1mg/kg).