Endocrinology Flashcards
give the abnormalities and causes
HAGMA - DKA, renal failure and lactic acidosis
metabolic acidosis from vomiting causing normal PH
high K from renal failure
type a Lactic acidosis
high creatinine from pre renal failure
What are the management steps?
insulin 5unites/hr until acidosis resolved
IV fluids – N/S (bolus acceptable 1000mL stat) initially 1 litre over 1 hour then replace losses plus maintenance over 24-48hrs, add 5% dextrose when BSL falls to 12-15, maintain BP >100mmHg and cerebral perfusion
K replacement – will fall with insulin – add 40mmol/L to infusion when K falls to 4.5 – 5.0
only if passing urine (care with chronic renal failure)
Treat cause (eg sepsis, abdominal pathology)
interpret gas
Severe metabolic acidosis with adequate respiratory compensation
High anion gap metabolic acidosis. Likely secondary to DKA given the high glucose
Na is high – 160 and even higher when corrected – 160 + (44-10/3) = 171. Likely secondary to water loss – glycosuria. Potassium is low – acidaemia usually drive K up, so corrected will be even lower.
Delta AG/HCO3 – 1
Hyperosmolality – (2x160) + 44/18 + 5.3/2.8 = 324
what are the mangement priorities
Move to resus – needs monitoring in view of hypokalaemia and hypernatraemia. Needs
x2 IVC, may need central access if K drops when resuscitation starts
Needs 1 litre NS immediately
Start insulin infusion at rate of 0.1 unit per kg/hr. Aim to drop BSL 2-4 per hour
K replacement – may need central line. 10mmol/hour
Need to monitor K and Na – at risk of seizures with large drops of Na level
what are the explanations for the abnormalities?
HCO3 – high anion gap metabolic acidosis due to renal failure, probably also lactate and ketones Formula: anion gap = Na – (HCO3 + Cl)
Glucose – due to HHS, as a result of poor glycaemic control in the context of sepsis Na – dilutional due to hyperglycaemia, corrects to 139 – normal
Formula: corrected Na = Na + (glucose-5)/3
K – elevated due to intracellular shift from likely acidaemia, and also renal failure
Urea,creat – renal failure, intrinsic as ratio <100, probably due to ATN and maybe pyleonephritis
Give four differentials other than myxodemic coma
neuro - seizure of ICH
endocrinology - addisons
infective - sepsis
hypothermia
tox - opiates, barbituates
other than non compliance to meds what are some causes of myxodemic coma?
trauma
concurrent illness eg pneumonia
Mi events
CVA events
hypothermia
meds eg lithium
how do you treat a myxodemic coma that is caused by medication non compliance?
- Replace T3 and T4
t4 = 200-400mcg IV loading dose
t3 - 5-20mcg IV - Hydrocortisone
- Supportive care - fluids, electrolyte replacement, vasopressors
What is the most likely diagnosis and some differentials?
Thyroid Storm
heat related ilness
SOL
sepsis -meningioencephalitis
toxidrome eg sympathomimetic or anticholinergic
withdrawal - benzos or alcohol
What are four risk factors for thyroid storm?
sepsis
acute MI
DKA
trauma
IV iodine contrast
ingestied thyroid hormone
What are the treatment priorities for thyroid storm?
ABC supportive care
IV benzos
anti thyroid medications
treat underlying cause
corticosteroids
consult endocrine
block peripheral effects eg beta blocker
stop synthesis - carbimazole
What are the drug treatments for thyroid storm?
- block peripheral effect - 1mg IV propranolol every 5 to 10 minutes
- stop synthesis - carbimazole 900-1200mg PO
- ioidine - prevents release of stored hormones - lugols iodine 8-10 drops
- steroids - 100mg hydrocort stops peripheral conversion
What is Pembertons sign?
What causes it?
Triad:
Facial congestion
Cyanosis
Respiratory distress
Usually SVC obstruction from tumour or mass
What are the diagnostic criteria for thyroid storm?
fever
tachycardia disproportionate to fever
CNS disturbance
what the physical exam features of thyrotoxicosis
tachy
sweaty
febrile
tremor
hyperreflexia
goitre
exopthalmos
thin hair
list three causes of thyrotoxicosis and the exam findings
