see also: [[Long QT]] > corrected Ca < 2.1 normal serum corrected calcium - 2.1-2.6 mmol/L normal serum ionised calcium - 1.1-1.3 > [!TLDR] clinical features > **Acute** > - muscle cramps > - tetany (esp carpo-pedal spasm) -- uncommon unless ionized calcium is <1.1, which usually corresponds to serum total calcium of 1.8 > - circumoral and distal parasthesia nad numbness > - *chvostek's sign* -- tap over facial nerve anterior to ear, twitching of mouth, nose, face . look for conraction of facial muscles > - *trousseau sign* -- BP cuff inflation causes carpal spasm. carpopedal spasm > - hyper-reflexia > - [[Seizures]] > - [[Long QT|prolonged QT]] > - however, ==far less common to get torsades than with hypokalemia or hypomagnesaemia== > > **Chronic** > - confusion / dementia > - EPS signs # Tox Causes - [[Hydrofluoric Acid]] - [[toxic alcohols#Ethylene Glycol|Ethylene Glycol]] → (HAGMA + ↓ Ca ) - [[Valproate]] # General causes - [[Acute Renal Failure]] - thyroid surgery (hypoparathyroid) - ==hypoparathyroid most common== - [[Hypomagnesemia]] - can be a/w ==EtOH abuse and malabsorption==, another common cause - can also cause dysfunction of PTH and parathyroid hormone resistance - hyper-phosphate - renal failure - hypoalbuminaemia -- check ionized or corrected levels - Alkalosis can reduce serum ionised calcium - impaired viatamin D metabolism - malnutrition - chronic renal failure - liver disease - Drugs - ==loop diuretics== - bisphosphonates - [[rhabdomyolysis]] - acute [[pancreatitis]] - [[Massive blood transfusion]] - cirate used as an anicoagulant chelates calcium - in these cases, total calcium is normal while ionized calcium is reduced as a result of the citrate binding - pregnancy ## dataview ```dataview LIST FROM "Toxicology" AND ([[Hypocalcemia]] OR #hypocalcemia) SORT file.name ASC ``` # ECG changes - [[Long QT|prolonged QTc]] **without** U waves - however, does not appear to be major risk factor for torsades # Tests ## Correction for albumin - normally ~ half total plasma bound to plasma albumin, so total calcium varies with albumin concentration - ionized calcium (free calcium) is the only thing that affects physiology - therefore, ==if albumin is significantly low, then corrected calcium will increase== - for example, in hypoalbuminaemia in liver disease and nephrotic syndrome, apparently low total calcium concentrations may be accompanied by a normal ionised calcium concentration, and correction is not required ## correction for pH ionized calcium rises 0.05 mmol/L for each 0.1 decrease in pH # Treatment - 5mL of 10% calcium chloride or 10 mL of 10% calcium gluconate IV - may be repeated 2x as necessary - oral supplementation - calcium carbonate 500-750mg - [[Hypomagnesemia|magnesium repletion]] essential - Vitamin D 1000 U/day - tx underling disease - in hypoparathyroidism resistant to Ca supplimentation, can inject recombinant parathyroid hormone daily