Electrolytes Flashcards
most important electrolyte abnormalities to know about
hypercalcaemia
Hyperkalaemia
hyponatraemia
ECG changes seen in Hyperkalaemia
low flat p waves
tall tended T waves
broad QRS
up slurring into ST segment
causes of Hyperkalaemia
AKI/CKD K+ rich diets drug induced hypoaldosteronism increased release from cells (DKA, rhabdomyolysis, strenuous exercise, tumour lysis)
drugs which cause Hyperkalaemia
ACEi/ARB spironolactone heparin/LMWH trimethoprim beta blockers
treatment of Hyperkalaemia
calcium gluconate (10mls 10%)
ECG monitoring
IV insulin (10 units)+ dextrose (50mls 50%)
salbutamol nebuliser
how do you treat Hyperkalaemia for people on dialysis
treated with their regular dialysis
causes of Hypercalcaemia
primary hyperparathyroidism malignancy granulomatous disease drugs immobilisation (due to bone and mineral loss) drugs (vit D, lithium, thiazides) thyrotoxicosis familial hypercalciuric hypercalcaemia
treatment for Hypercalcaemia
fluids -IV NaCl 0/9% 4-6L/24 hours
bisphosphonates - only licensed for tumour induced hypercalcaemia
clinical features of hypercalcaemia
(bones, stones, groans, psychiatric moans)
- bone pain
- renal stones
- mood distrubance
- abdo pain - nausea & constipation
ECG changes in hypercalcaemia
shortened QT interval bloods- FBC, renal core, bone profile, PTH myeloma screen CXR serum ACE
causes of hypernatraemia
excess water loss:
- skin - sweating/burns
- gut- diarrhoea, vomiting, fistulae
- renal- diuretics, diabetes insidious, osmotic diuresis
what is osmotic diuresis
increased urine production to get rid of substances in blood eg. glucose in DKA
how do you calculate serum osmolality
2x Na + urea + glucose
treatment for hypernatraemia
oral rehydration (oral water/glucose 5%) IV dextrose
at what rate should you reduce serum Na and what happens if its reduced to fast
no more than 10mmol/24 hours
if reduced too quickly can cause rapid brain expansion and tentorial herniation
causes of hypokalaemia
loop and thiazide diuretics
D&V
re-feeding syndrome
treatment of hypokalaemia
oral replacement - K tablets
IV replacement - rate of infusion should not exceed 10mmol/hour
how does hypocalcaemia present
muscle cramps
parasthesia
tetany
carpopedal spasm
treatment of hypocalcaemia
oral calcium supplement
vit D supplement
if severe (<1.9)
- caclium gluconate 10% in 5% glucose
- follow with continuous IV infusion
ECG presentation of hypocalcaemia
QT prolongation
cardiac monitoring
what other electrolyte should you also check in hypoclacaemia
magnesium (can also be low)
whats the first thing you do in hyponatraemia
check serum osmolarity
if serum osmolarity low - asses fluid stasis
if serum osmolarity high - could be hyperglycaemia (or pseudo causes)
causes of hyponatraemia when urine sodium is also low
acute water overload
malnutrition
polydipsia
causes of hyponatraemia when urine sodium is high
glucocorticoid deficiency (Addisons disease)
SIADH
ACTH
hypothyroidism
