eMedicine Specialties > Pediatrics: General Medicine > Endocrinology

Hypermagnesemia: Differential Diagnoses & Workup

Author: Anastasios K Konstantakos, MD, Clinical Associate Surgeon, Department of Cardiovascular Surgery, Billings Clinic, Billings, Montana
Contributor Information and Disclosures

Updated: May 5, 2009

Differential Diagnoses

Adrenal Insufficiency
Hypocalcemia
Hypokalemia
Hypoparathyroidism
Hypothyroidism
Rhabdomyolysis

Workup

Laboratory Studies

  • Laboratory analysis by atomic absorbance spectrophotometry (AAS) is the most specific technique available for measuring total serum magnesium in patients with suspected hypermagnesemia.
  • Although ion-selective electrodes for measuring free magnesium have been developed, their use has not been tested rigorously, and they are not readily available on a wide-scale basis.
  • Hypermagnesemia usually is not found as an isolated electrolyte abnormality; hyperkalemia and hypercalcemia often are present concurrently. Hypermagnesemia may secondarily cause hypocalcemia by suppressing parathyroid hormone (PTH) and by directly suppressing non–PTH-mediated renal tubular calcium reabsorption.
  • Obtain BUN and creatinine levels to determine the presence of renal insufficiency, as serum magnesium levels rise when the creatinine clearance is less than 30 cc/min.
  • Check creatine phosphokinase (CPK) or urine myoglobin in patients with suspected rhabdomyolysis.
  • Because hypothyroidism and adrenal insufficiency are rare causes of hypermagnesemia, perform thyroid function tests and at least an early morning serum cortisol test in recurrent or refractory cases of hypermagnesemia.

Other Tests

  • An ECG and cardiac monitor may demonstrate prolongation of the P-R interval, intraventricular conduction delay, or other nonspecific findings.

More on Hypermagnesemia

Overview: Hypermagnesemia
Differential Diagnoses & Workup: Hypermagnesemia
Treatment & Medication: Hypermagnesemia
Follow-up: Hypermagnesemia
Multimedia: Hypermagnesemia
References
Further Reading
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References

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  2. Musso CG. Magnesium metabolism in health and disease. Int Urol Nephrol. Mar 10 2009;[Medline].

  3. Kaze Folefack F, Stoermann Chopard C. [Magnesium metabolism disturbances]. Rev Med Suisse. Mar 7 2007;3(101):605-6, 608, 610-1. [Medline].

  4. Moe SM. Disorders involving calcium, phosphorus, and magnesium. Prim Care. Jun 2008;35(2):215-37, v-vi. [Medline].

  5. Navarro-Gonzalez JF, Mora-Fernandez C, Garcia-Perez J. Clinical implications of disordered magnesium homeostasis in chronic renal failure and dialysis. Semin Dial. Jan-Feb 2009;22(1):37-44. [Medline].

  6. [Best Evidence] Ford AA, Wylie BJ, Waksmonski CA, Simpson LL. Maternal congenital cardiac disease: outcomes of pregnancy in a single tertiary care center. Obstet Gynecol. Oct 2008;112(4):828-33. [Medline].

  7. Corbi G, Acanfora D, Iannuzzi GL, et al. Hypermagnesemia predicts mortality in elderly with congestive heart disease: relationship with laxative and antacid use. Rejuvenation Res. Feb 2008;11(1):129-38. [Medline].

  8. Ali A, Walentik C, Mantych GJ, et al. Iatrogenic acute hypermagnesemia after total parenteral nutrition infusion mimicking septic shock syndrome: two case reports. Pediatrics. Jul 2003;112(1 Pt 1):e70-2. [Medline].

  9. Durham D, Worthley LI. Cardiac arrhythmias: diagnosis and management. The tachycardias. Crit Care Resusc. Mar 2002;4(1):35-53. [Medline].

  10. Henyan NN, Gillespie EL, White CM, et al. Impact of intravenous magnesium on post-cardiothoracic surgery atrial fibrillation and length of hospital stay: a meta-analysis. Ann Thorac Surg. Dec 2005;80(6):2402-6. [Medline].

  11. Knochel JP. Disorders of magnesium metabolism. Harrison's Principles of Internal Medicine. 1994;2:2187-2189. [Medline].

  12. Nadler JL, Rude RK. Disorders of magnesium metabolism. Clinical Disorders of Fluid and Electrolyte Metabolism. 1995;24:623-637. [Medline].

  13. Rude RK, Singer FR. Magnesium deficiency and excess. Ann Rev Med. 1981;32:245-259. [Medline].

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Keywords

hypermagnesemia, magnesium, Mg, elevated serum magnesium, acute renal failure, fatal hypermagnesemia, diabetic ketoacidosis, dehydration, pregnancy-induced hypertension, renal insufficiency, eclampsia, respiratory depression, heart block, asystole, hypotension, treatment, diagnosis

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Contributor Information and Disclosures

Author

Anastasios K Konstantakos, MD, Clinical Associate Surgeon, Department of Cardiovascular Surgery, Billings Clinic, Billings, Montana
Disclosure: Nothing to disclose.

Medical Editor

Phyllis W Speiser, MD, Chief of Pediatric Endocrinology, Schneider Children's Hospital; Professor of Pediatrics, New York University School of Medicine
Phyllis W Speiser, MD is a member of the following medical societies: American Association of Clinical Endocrinologists, Endocrine Society, Lawson-Wilkins Pediatric Endocrine Society, and Society for Pediatric Research
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine
Disclosure: Pfizer Inc Stock Investment from financial planner; Avanir Pharma Stock Investment from financial planner ; WebMD Salary and stock Employment and investment from financial planner

Managing Editor

George P Chrousos, MD, FAAP, MACP, MACE, FRCP(London), Professor and Chair, First Department of Pediatrics, Athens University Medical School, Aghia Sophia Children's Hospital, Greece
George P Chrousos, MD, FAAP, MACP, MACE, FRCP(London) is a member of the following medical societies: American Academy of Pediatrics, American College of Endocrinology, American College of Physicians, American Pediatric Society, American Society for Clinical Investigation, Association of American Physicians, Endocrine Society, Lawson-Wilkins Pediatric Endocrine Society, and Society for Pediatric Research
Disclosure: Nothing to disclose.

CME Editor

Merrily P M Poth, MD, Professor, Department of Pediatrics and Neuroscience, Uniformed Services University of the Health Sciences
Merrily P M Poth, MD is a member of the following medical societies: American Academy of Pediatrics, Endocrine Society, and Lawson-Wilkins Pediatric Endocrine Society
Disclosure: Nothing to disclose.

Chief Editor

Stephen Kemp, MD, PhD, Professor, Department of Pediatrics, Section of Pediatric Endocrinology, University of Arkansas and Arkansas Children's Hospital
Stephen Kemp, MD, PhD is a member of the following medical societies: American Academy of Pediatrics, American Association of Clinical Endocrinologists, American Pediatric Society, Endocrine Society, Phi Beta Kappa, Southern Medical Association, and Southern Society for Pediatric Research
Disclosure: Genentech, Inc. Honoraria Speaking and teaching; Pfizer, Inc. Honoraria Consulting

 
 
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