Flashcards in metabolic disturbances Deck (25):
how does hyperventilation lead to hypocalcemia?
hyperventilation leads to Co2 being blown off --> respiratory alkalosis. As a compensatory effect, H+ dissociates from proteins to reduce pH. As proteins become negatively charged, calcium binds to these proteins leading to hypocalcemia.
what is chovsteks sign?
tapping on the parotid gland/facial nerve leads to muscle spasm like activity; indicating latent tetany. this is a sign of hypocalcemia
what is trousseaus sign of latency?
indicates hypocalcemia. Blood pressure cuff is applied to arm, and pumped up until over systolic BP. wait for 2 mins and then hypocalcemia + neuromuscular irritability cause the hand to flex and come together.
Can also be due hyperaldosteremia due to adrenal gland malignancy leading to uncontrollable HT and hyperkalemia
what do we think when we see hypercalcemia?
we either think primary hyperparathyroidism or malignancy
what do we think when we see hypokalemia, hyponatriemia and hypovolemia?
Addisonian crisis/ adrenal crisis
what causes hyponatremia hypervolemia?
• Water retention
• Chronic organ failure
• Kidney, heart, liver
what causes hyponatremia euvolemia?
SIADH and psycogenic polydipsia
what causes hyponatremia hypovolemia?
diarrhoea, thiazide diuretics, adrenal crisis
what is a complication of chronic hyponatremia?
cerebral pontine myelinolysis
what are the differential diagnoses for hyperphosphatemia?
1. Renal impairment
3. Exogenous source
4. Tumour lysis syndrome
5. vitamin D toxicity
what can cause raised LDH?
2. muscle problems (rhabdomyolysis, MI etc)
3. liver problems
How to manage hypercalcemia??
• Normal saline to dilute calcium- SALINE REHYDRATION
• Loop diuretics
Patients should restrict Ca intake after a calcium stone? T or F
False. The dietary calcium intake is actually inversely related to the formation of calcium stones.
where is B12 absorbed?
where is iron absorbed?
What are some symptoms of hypercalcemia?
• Renal stones
• Muscle fatigue (weakness), hyporeflexia
• Cardiac arrest/VF
• Nephrogenic diabetes insipidus--> dehydration
what is the mnemonic for hypercalcemia
moan bone stone groan
what do we mean by "brown tumours'
these are lytic bone lesions that indicate increased osteoclastic activity secondary to parathyroid tumours
what are some causes of SIADH
what are the symptoms of hyponatremia?
How does it differ to hypernatremia?
Generally only occur when sodium levels are very low.
• Moderate hyponatremia--> confusion, muscle cramps
Severe hyponatremia--> coma, convulsions
same symptoms as hypernatremia however these symptoms are more common in hypernatremia as you need a large sodium deficit to get these symptoms
how to calculate tonicity?
2 X NA + UREA + GLUCOSE
what ix to order for hypercalcemia?
• U and E/ glucose
• Serum calcium level
• Parathyroid hormone levels
• Vit D levels
Imaging for malignancy- CXR, CT scan
complications of hypernatremia?
• Cerebral haemorrhages
• Intracranial venous sinus thrombosis
• Cerebral oedema if corrected too quickly
which endocrine disorder causes hypernatremia?
diabetes insipidis because of constant water loss (due to reduced ADH production) leading to serum hypernatremia and increased osmolality