Skip to main content Accessibility help

Do intracellular, extracellular or urinary magnesium concentrations predict renal retention of magnesium in critically ill patients?

  • P. Saur (a1), P. D. Niedmann (a2), E. Brunner (a3) and D. Kettler (a1)



Background and objective: Magnesium disorders are common in hospitalized patients. In patients with low or normal magnesium, the intravenous magnesium loading test has been demonstrated to be a sensitive test to assess magnesium deficiency in critically ill patients. However, it is more time consuming and more difficult than the measurement of intracellular or extracellular magnesium concentrations. This study evaluated whether erythrocyte, plasma and urinary magnesium concentrations predict renal magnesium retention measured by the magnesium loading test.

Methods: One-hundred-and-three intensive care patients (36 females, 67 males) in a tertiary care centre and 41 healthy subjects (13 females, 28 males) took part in this prospective study. Intracellular, total plasma, ionized extracellular and urinary magnesium concentrations were measured and also magnesium retention by intravenous magnesium loading test.

Results: Total plasma magnesium concentration was poorly correlated with magnesium retention (r = 0.36, r2 = 0.13) and was the only parameter that significantly predicted magnesium retention in intensive care patients (P < 0.01). However, only 10% of the magnesium retention data were linked to the total plasma magnesium concentration.

Conclusions: Total plasma magnesium concentration predicts magnesium retention in critically ill intensive care patients but not intracellular and urinary magnesium concentrations. Only a small proportion of the magnesium retention was due to the total plasma magnesium concentration.


Corresponding author

Correspondence to: Petra Saur, Department of Anesthesiology, Emergency- and Intensive-Care-Medicine, Georg-August-University of Goettingen, D-37075 Goettingen, Germany. E-mail:; Tel: +49 551 396052; Fax: +49 551 398676


Hide All


Altura BM. Introduction: importance of magnesium in physiology and medicine and the need for ion selective electrodes. Scand J Lab Invest 1994; 217: S5S9.
Quamme GA. Magnesium homeostasis and urinary magnesium handling. Miner Electrolyte Metab 1993; 19: 218225.
Salem M, Munoz R, Chernow B. Hypomagnesemia in critical illness. Crit Care Clin 1991; 7: 225252.
Chernow B, Bamberger S, Stoiko M, et al. Hypomagnesemia in patients in postoperative intensive care. Chest 1989; 95: 391397.
Whang R. Clinical disorders of magnesium metabolism. Compr Ther 1997; 23: 168173.
Frankel H, Haskell R, Lee SY, Miller D, Rotondo M, Schwab CW. Hypomagnesemia in trauma patients. World J Surg 1999; 23: 966969.
Rubeiz GJ, Thill-Baharozian M, Hardie D, Carlson RW. Association of hypomagnesemia and mortality in acutely ill medical patients. Crit Care Med 1993; 21: 203209.
Ryzen E. Magnesium homeostasis in critically ill patients. Magnesium 1989; 8: 201212.
Gullestad L, Dolva LO, Waage A, et al. Magnesium deficiency diagnosed by an intravenous loading test. Scand J Clin Lab Invest 1992; 52: 245253.
Ryzen E, Elkayam U, Rude RK. Low blood mononuclear cell magnesium in intensive cardiac care unit patients. Am Heart J 1986; 111: 475480.
Saur PMM, Zielmann S, Roth ATP, et al. Evaluation of magnesium deficiency in patients of an intensive care unit. Anaesth Intensivmed Notfallmed Schmerzther 1996; 1: 3741.
Ryzen E, Elbaum N, Singer FR, Rude RK. Parenteral magnesium tolerance testing in the evaluation of magnesium deficiency. Magnesium 1985; 4: 137147.
Khalil SI. Magnesium the forgotton cation. Int J Cardiol 1999; 68: 133135.
Rude RK, Singer FR. Magnesium deficiency and excess. Ann Rev Med 1981; 32: 245259.
Quamme GA. Laboratory evaluation of magnesium status. Urinary function and free intracellular magnesium concentration. Clin Lab Med 1993; 13: 209213.
Sanders GT, Huijgen HJ, Sanders R. Magnesium in disease: a review with special emphasis on the serum ionized magnesium. Clin Chem Lab Med 1999; 37: 10111033.
Elin RJ. Magnesium metabolism in health and disease. Dis Mon 1988; 34: 161218.
Thode J, Juul-Jorgensen B, Seibaek M, Elming H, Borresen E, Jordal R. Evaluation of an ionized magnesium-pH analyser-NOVA8. Scand J Lab Invest 1998; 58: 127133.
Jelicks LA, Weaver J, Pollack S, Gupta RK. NMR studies of intracellular free calcium, free magnesium and sodium in the guinea pig reticulocyte and mature red cell. Biochim Biophys Acta 1989; 15: 261266.
Carroll RG, Kerrigan DC, Bray JT, Foil MB, Cunningham PR. Increase in renal magnesium overflow following aortotomy induced hemorrhage in pigs. Circ Shock 1992; 32: 103107.


Do intracellular, extracellular or urinary magnesium concentrations predict renal retention of magnesium in critically ill patients?

  • P. Saur (a1), P. D. Niedmann (a2), E. Brunner (a3) and D. Kettler (a1)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed