Calcium, magnesium and phosphate disorders — viva

Opening (must-hit)

"This child has severe symptomatic hypocalcaemia with neuromuscular excitability, and the fact that it has not corrected after two adequate doses of calcium gluconate tells me the problem is magnesium. Hypomagnesaemia suppresses parathyroid hormone release and produces a functional hypoparathyroidism that no amount of calcium will fix, so my immediate next step is to check the magnesium and replace it with intravenous magnesium 0.1 to 0.2 mmol per kilogram (maximum 8 mmol) over 2 to 4 hours. I continue cardiac monitoring and I look for the cause of the magnesium loss — diuretics, proton pump inhibitors, a Gitelman picture, or an inherited tubulopathy." ^[1][7]