The purpose of this present study was to assess the prevalence of hypermagn
esaemia in a hospital population. Furthermore, the relationship between hyp
ermagnesaemia and other common electrolyte disturbances such as hypo- and h
ypercalcaemia, hypo- and hyperkalaemia and hypo- and hyperphosphataemia was
studied.
Twenty-seven percent of magnesium requests showed a serum magnesium concent
ration equal to, or greater than, 1.0 mmol/l.
Hyperkalaemia (a plasma potassium concentration of equal to, or greater tha
n, 5.0 mmol/l) was found in 18% of the patients with hypermagnesaemia and 2
5% of these patients showed hyperphosphataemia (a plasma phosphate concentr
ation of equal to, or greater than, 1.5 mmol/l).
Of the serum magnesium requests, hypermagnesaemia was particularly common o
n the intensive care (23%) and the renal unit (43%). Hypermagnesaemia was a
lso seen in patients undergoing cardiothoracic surgery (17%) and who had an
acute myocardial infarction (8%). Seventy-three percent of patients with a
plasma magnesium of greater than 1.0 mmol/l showed abnormal renal function
. However, it was rare to find a serum magnesium of greater than 2.0 mmol/l
(less than 1% of magnesium requests).