metabolic Flashcards
causes hyperK
AKI // meds // met acidosis // addisons // rhabdo // massive blood transfusion
drugs that cause hyperK
ACEi // ARBs // sprinolactone // ciclosporin // heparin // (BB in kidney failure)
ECG hyperK
tented T waves // loss of p // broad QRS // sinudoidal wave // v fib
mild, moderate, severe hyperK
mild 5.5-5.9 // moderate 6-6.4 // severe >6.5
mx hyperK
IV calcium gluconate (stabilise cardiac membrane) // IV dextrose+insulin (shift K from ECF –> ICF) // calcium resonium, diuretisc, dialysis (remove K)
relationship with K ions and H ions
they compete with each other - high K means less H can enter cells and vice versa
causes hypoK alkalosis
vomiting // thiazide + loop diuretics // cushings // conn’s
causes hypoK acidosis
diarrhoea // renal tubular acidosis // acetazolamide
what other deficiency can cause hypoK
hypoMg
symptoms hypoK
weakness, hypotonia
ECG hypoK
U wave // small T wave // prolonged PR // St depression
hypoK with hypertension
Cushings // conns // liddles
hypoK w/o hypertension
diuretics // GI loss (diarrhoea or vomitting) // renal tubular acidosis // Bartters
inheritance Liddle’s
dominant
features liddles
hypertension + hypoK alkalosis
mx LIddles
amiloride or triamterene
inheritence Bartters
autosomal recessive
mechanism Bartters
defective Cl absorption from NaKCl transporter (work like loop diuretics)
most common cause hypercalcaemia in non-hospital patients
primary hyperparathyroid
most common cause hypercalcaemia in hospital patients
malignancy
how does malignancy cause hyperCa
PTHrP from tumour eg squamous cell lung cancer // bone mets // myeloma
invx hyperCa
PTH
other key causes hyperCa
sarcoid // vit D intoxication // acromegaly // thyrotoxicosis // thiazides // dehydrated // addisons // pagets
symptoms hyperCa
bones, stones (kidney), groans , psychic moans // corneal calcification // HTN
ECG hyperCa
short QT
initial mx hyper Ca
rehydration with saline (3/4L per day)
secondary mx hyper Ca
bisphosphonates // calcitonin // loops (can worsen U+Es)
causes hypo Ca
vit D def (osteomalacia) // CKD // hypoparathyroud // rhabdo // mg deficiency // blood transfusion // acute pancreatitis
invx hypo Ca
history + PTH
symtoms hypo Ca
tetany - muscle twitch or spasm // perioral parasthesia // depression // cataracts
hypo Ca ECG
prolonged QT
trousseaus sign hypo Ca
blood pressure cuff –> occlude brachial artery (above systolic) –> carpal spasm
chvoteks sign hypo Ca
tapping parotid –> facial twitch
mx hypo Ca
IV calcium gluconate + ECG monitoring
indications urgent mx hypo Ca
carpal spasm, tetany, seizure, prolonged QT
Mg relationship with Ca
Mg required for PTH secretion and action on targets // so low Mg –> low Ca and little response to Ca or Vit D mx
causes hypo mg
diuretics and PPI // parenteral nutrition // diarrhoea // alcohol // hypoK and hyperCa // metabolic disorders
how does hyperCa cause hypo Mg
hyperparathyroid ism
symptoms hypoMg
(similar to hypoCa) // paraesthesia, tetany, seizure, arrhythmia, decreased PTH, ECG –> hypoK, digoxin toxicity
mx hypo Mg if <0.4
IVmagnisium (if tetany, arrythmia, seizure)
mx hypoMg >0.4
oral mg salts
se mg salts
diarrhoea
relationship between Na, K, H
sodium exchanged for K and H (reduces them both)
causes hyper Na
dehydrated // osmotic diuresis eg HONK // diabetes insipidus // too much saline
risk of correcting hyperNa too quickly
cerebral oedema –> seizure, coma, death
rate to give saline hyperNa
no more 0.5 mmol/hr
inheritence and defect liddles syndrome
autosomal dom // disorder Na channels in distal tubule –> increased Na
symptoms Liddles
HTN + hypoK alkalosis
mx LIddles
amiloride or triamtrene (K sparing diuretic)
causes of hypoNa with urinary Na >20 (5)
Na depletion = diuretic, addisons, renal failure // others = SIADH, hypothyroid
causes hypoNa with urinary Na <20
