Editing Calcium (section)

== '''Hypocalcaemia''' ==

* Remember to correct against the albumin level or confirm with an ionised level
* '''Aetiology'''
** Hypoparathyroidism
** Alkalosis
** Blood transfusions
** Drugs - aminoglycosides, heparin
** Fat embolism
** Magnesium depletion (promotes hypocalcaemia by inhibiting PTH secretion) - refractory to calcium replacement - '''just need to correct the magnesium'''
** Pancreatitis
** Renal insufficiency
** Sepsis (unclear mechanism)
* '''Manifestations'''
** Neuromuscular excitability - tetany, hyper-reflexia, paraesthesias, siezures. Chvostek's and Trousseau's signs are non-specific and non-sensitive respectively.
** Cardiovascular - hypotension, decreased CO, ventricular ectopics
* '''Acute severe hypocalcaemia''' (tetany, laryngospasm, seizures)
** calcium gluconate 10% 20 mL (4.4 mmol elemental calcium) in sodium chloride 0.9% 100 mL intravenously over 20 minutes (ensure good IV access as it will cause skin necrosis if tissued); repeat if required; followed by calcium gluconate 10% 100 mL (22 mmol elemental calcium) in sodium chloride 0.9% 900 mL by intravenous infusion at an initial rate of 50 mL/hour (1.1 mmol elemental calcium/hour). Titrate to maintain a corrected serum total calcium concentration of 2.0 to 2.3 mmol/L
** Cardiac monitoring for duration of therapy
** Measure calcium every 4 hours
* '''Moderate hypocalcaemia''' (muscle cramps, spasms, paraesthesiae):
** calcium carbonate 1.25 to 1.5 g (elemental calcium 500 to 600 mg) orally, twice daily, with food (can also use calcium citrate if unavailable)
** Also give oral colecalciferol (vitamin D)
** Measure every 1-2 weeks
* '''Long-term monitoring'''
** Aim for lower limit of reference range - avoid symptoms rather than necessarily get it into the reference range
** Check levels every 6 months
* '''Treatment'''
** Indications for IV replacement:
*** Symptoms
*** Prolonged QT interval
*** <=1.9mmol/L
** Indications for PO replacement:
*** Chronic hypocalcaemia
*** Acute hypocalcaemia not meeting requirements for IV replacement

[[Category:Nutrition]]
[[Category:Intern education]]