ASSCC 3 Flashcards
Management of Addisonian crisis:
1) CCrISP
2) Hydrocortisone 100mg IV / IM bolus
3) Continuous infusion Hydrocortisone 200mg / 24hrs
4) 1L Normal saline IV over 1st hour
5) IV fluids usually 4-6L over 24hrs
6) Urgent endocrinologist r/v
At what dose of daily steroid should you add steroid on day of surgery to prevent addisonian crisis?
> 10mg steroid/day
Causes of post-thyroidectomy hypocalcaemia:
1) Removal of parathyroid glands
2) Ischaemia of parathyroid glands (inf thyroid artery damage)
How is calcium transported in blood?
50% unbound, ionised
45% bound to plasma proteins
5% ass/w anions (citrate, lactate)
7 functions of Ca2+:
1) Muscle contraction
2) Neurotransmitter
3) Bone mineralisation
4) Enzyme activation
5) Glycogen metabolism
6) Cell division
7) Blood coagulation
3 hormones involved in calcium homeostasis:
1) Parathyroid hormone
2) Calcitriol
3) Calcitonin
Effect of PTH on Ca2+:
1) Bone resorption ^Ca2+
2) Renal reabsorption ^Ca2+ (in exchange for phosphate)
3) Stimulates 1α-hydroxylase in kidneys = ^calcitriol formation
Effect of calcitriol on Ca2+:
1) Gut absorption ^Ca2+
2) Renal reabsorption ^Ca2+ (and phosphate)
3) Bone resorption (+calcification)
Effect of calcitonin on Ca2+ :
1) Inhibits bone resorption when Ca2+ > 2.6
2) Stimulates renal excretion Ca2+
3 organs involved in calcitriol formation:
1) Skin
2) Liver
3) Kidneys
Signs of hypocalcaemia:
1) Cramps
2) Irritation
3) Peripheral/circumoral parasthesia
4) Spasms/tetany
5) Chvostek’s sign - tap ant to tragus
6) Trosseau’s sign - tap on median nerve with BP cuff on
Which muscle are you worried about in hypocalcaemia?
Laryngeal muscles - laryngospasm
Treatment of hypocalcaemia:
1) CCrISP
2) Cardiac monitoring
3) 10ml of 10% Calcium gluconate IV
4) 10-40ml of 10% calcium gluconate in saline infusion over 4-8hrs
5) Fluid resuscitation
7 ADRs of opioids:
1) Respiratory depression
2) N&V
3) Constipation
4) Hypotension
5) Confusion
6) Itching
7) Pin-point pupil
7 Complications of pain:
1) ^HR
2) ^BP
3) MI
4) Delayed gastric emptying
5) Reduced bowel motility / paralytic ileus
6) Atelectasis + retained secretions, pneumonia
7) Immobility -> DVT
5 problems with PCA:
1) Pt must be alert and orientated
2) May break/run out of battery
3) Sleep disturbance
4) Not suitable for confused pts or pts who physically cannot press button
5) Limits pts mobility
Difference between T3 and T4:
T3 = more biologically active, less protein bound T4 = less active, more protein bound
5 steps of synthesis of T3 + T4:
1) Iodide ions enter follicular cell
2) Iodide to Iodine via TOP
3) Iodine + Tyrosine –> MIT + DIT
4) MIT + DIT -> T3
5) DIT + DIT -> T4
? cause anaemia in hashimotos thyroiditis:
Macrocytic anaemia
Due to B12 deficiency (anti parietal autoantibodies = lack of intrinsic factor)
5 causes of primary hypothyroidism:
1) Autoimmune- Hashimoto’s
2) Iatrogenic - Thyroidectomy, Carbimazole
3) Transient thyroiditis - Dequervains
4) Iodine deficiency
5) Infiltrative - Sarcoidosis, Amyloidosis
8 signs hypothyroidism:
1) Cold intolerance
2) Weight gain
3) Constipation
4) Bradycardia
5) Myxoedema
6) Memory loss
7) Muscle weakness
8) Pretibial oedema
7 Indications for CT head < 1 hr:
1) GCS < 13 initial assessment
2) GCS <15 2hrs post injury
3) >1 episode vomiting
4) Suspected open or depressed skull fracture
5) Any sign of basal skull fracture
6) Post traumatic seizure
7) Focal neuro deficit
5 Indications for CT head < 8 hrs:
1) >65
2) Anticoagulation
3) Dangerous mechanism of injury
4) > 30 mins of retrograde amnesia
5) Bleeding or clotting disorder
Normal ICP:
7-15 mmHg
Describe Monroe-Kellie hypothesis in 3 sentences:
1) Skull is fixed bow containing 3 components: brain, CSF, blood
2) Increase in volume of 1 component = reduction in volume of another component to compensate
3) Once ICP >25mmHg, small increase in brain vol cause marked elevation in ICP
Define lucid interval:
Temporary improvement in patient condition after traumatic brain injury after which the condition deteriorates with rapid decline of consciousness
Cerebral perfusion pressure is defined as:
MAP - ICP
MAP auto-regulation range is:
50 - 150 mmHg
7 signs increased ICP:
1) Decreased GCS
2) Dilated pupil - oculomotor nerve palsy
3) Papilloedema
4) Defective lateral gaze - abducens nerve palsy
5) Headache
6) Nausea and vomiting
7) Cushings triad: ^sBP (widened pulse pressure), bradycardia, irregular RR
8 Indications for intubation:
1) GCS <= 8
2) Risk of raised ICP due to agitation
3) Inability to control/protect the airway or loss of protective laryngeal reflexes
4) A fall of 2 or more points in the motor component of GCS
5) To optimise oxygenation and ventilation
6) Seizures
7) Bleeding into mouth/airway
8) Bilateral fractured mandible
In case of raised ICP, how could you improve venous drainage?
- Elevate head of bed to 30’
- Good neck alignment, head in neutral position
- Ensure ties from ETT not compressing neck veins
- Immobilise neck with sandbag and collars rather than restrictive collars
In case of raised ICP, how could you reduce cerebral oedema?
- Mannitol = osmotic diuretic
- Furosemide = loop diuretic
- Maintain serum Na+ within normal range
In case of raised ICP, how could you reduce cerebral metabolic rate for oxygen?
- Close temperature regulation
- Use sedation and anaesthetic drugs
- If witnessed seizure consider anticonvulsant Levetiracetam (Keppra)
- If intractable consider Sodium Thiopental infusion
In case of raised ICP, how could you reduce intracranial blood volume?
Induce hyperventilation
- Breath off CO2
- CO2 = vasodilator
In case of raised ICP, what surgical procedures to relieve ?
1) External ventricular drain
2) Decompressive craniectomy
