see also:

• magnesium
• hypomagnesaemia

• high plasma magnesium levels is rare as the kidney is very efficient at excreting high levels
• it may be iatrogenic during iv magnesium sulphate infusions
• elevated levels of magnesium appear to have a “dose-dependent” correlation with increased mortality in sepsis / septicaemia ¹⁾

• iatrogenic due to iv infusion of magnesium
• renal failure

• usually asymptomatic

• lethargy
• drowsiness
• flushing
• nausea and vomiting
• diminished deep tendon reflexes

• somnolence
• loss of deep tendon reflexes
• hypotension
• ECG changes

• complete heart block
• cardiac arrest
• apnoea
• paralysis
• coma

• can be prevented by not using magnesium containing antacids or cathartics in patients with renal insufficiency.
• cease iv magnesium sulphate infusion if running
• iv calcium gluconate can be used as an antidote for hypotension and respiratory depression
• in patients with severe renal dysfunction, dialysis may be required.