He Brings To The Table The Right Foods

Large kindred. Critical Care Medicine

Volume 28 • Number 6 • June 2000

Copyright © 2000 Lippincott Williams & Wilkins

2022Hypomagnesemia and hypophosphatemia at admission in patients with severe

Head injurykees H. Polderman MD, phd 1Frank W. Bloemers MD 1Saskia M. Peerdeman MD 1Armand R. J. Girbes MD, phd 1

1 From the Surgical Intensive Care

Unit (Drs. Polderman and Girbes) and the Departments of Surgery (Dr.

Bloemers) and Neurosurgery (Dr. Peerdeman), University Hospital Vrije

Universiteit, Amsterdam, The Netherlands.

Copyright © 2000 by Lippincott Williams & Wilkins

Objective: Low serum levels of electrolytes such as magnesium (Mg),

Potassium (K), calcium (Ca), and phosphate (P) can lead to a number of clinical

Problems in intensive care unit (ICU) patients, including hypertension, coronary

Vasoconstriction, disturbances in heart rhythm, and muscle weakness. Loss of

These electrolytes can be caused, among other things, by increased urinary

Excretion. Cerebral injury can lead to polyuresis through a variety of

Mechanisms. We hypothesized that patients with cranial trauma might be at risk

For electrolyte loss through increased diuresis. The objective of this study was

To assess levels of Mg, P, and K at admission in patients with severe head


Design: We measured plasma levels of Mg, P, K, Ca, and sodium at

Admission in 18 consecutive patients with severe head injury admitted to our ICU

(group 1). As controls, we used 19 trauma patients with two or more bone

Fractures but no significant cranial trauma (group 2).

Setting: University teaching hospital.

Patients: Eighteen patients with severe head injury admitted to our

Surgical ICU (group 1) and 19 controls (trauma patients with no significant

Cranial trauma; group 2).

Main Results: Electrolyte levels at admission (group 1 vs. Group 2;

Mean ± SD, units: mmol/L) were as follows. Mg,

0.57 ± 0.17 (range, 0.24-0.85) vs. 0.88 ± 0.21 (range, 0.66-1.42 mmol/L; p

<.01). P, 0.56 ± 0.15 (range, 0.20-0.92) vs. 1.11 ± 0.15 (range, 0.88-1.44

Mmol/L; p <.01). K, 3.54 ± 0.59 (range, 2.4-4.8) vs. 4.07 ± 0.45

(range, 3.6-4.8 mmol/L; p <.02). Ca, 2.02 ± 0.24 (range, 1.45-2.51)

Vs. 2.14 ± 0.20 (range, 1.88-2.46; p = NS). In group 1, 12/18 patients

Had Mg levels <0.70 mmol/L vs. 2/19 patients in group 2 ( p <.01);

In group 1, 11/18 patients had P levels below 0.60 mmol vs. 0/19 patients in

Group 2 ( p <.01). Moderate hypokalemia (K levels, <3.6 mmol/L) was

Present in 8/18 patients in group 1 vs. 1/19 patients in group 2 ( p

<.01). Severe hypokalemia (K levels, 3.0)

Was present in 4/18 patients in group 1 vs. 0/19 patients in group 2 ( p


Conclusion: We conclude that patients with severe head injury are at

High risk for the development of hypomagnesemia, hypophosphatemia, and

Hypokalemia. One of the causes of low electrolyte levels in these patients may

Be an increase in the urinary loss of various electrolytes caused by neurologic

Trauma. Mannitol administration may be a contributing factor. Intensivists

Should be aware of this potential problem. If necessary, adequate.