Magnesium in the intensive care unit

Introduction and aims

Magnesium has been used since time immemorial as a purgative and uterine relaxant. Magnesium regulates many life processes and is the key factor in the production of ATP, the source of life energy. It is a natural calcium channel blocker and neutralizes the effect of catecholamines, it works very well on supraventricular and ventricular arrhythmias. We obtained excellent results on cardiac arrhythmias and drug induced supraventricular tachycardia (dopamine, dobutamine, noradrenaline, adrenaline and aminophylline). The aim of this prospective study is to know the affects of magnesium therapy on different critical conditions in the ICU.

Methods

Administer magnesium 5 g in D5W over 6–8 hours. The heart rate is monitored at 15, 30, 45, 60, 75 and 90 min, and then at 6 and 12-hour interval. To give the same dose for 5 consecutive days. Other parameters like urine output, creatinine and patient's survival were noted.

Results

Prospective study: 115 cases treated with magnesium (50 drug induced SVT, 20 SVT, 5 ARDS, 16 CCF, 7 CPR, 7 Diabetic ketoacidosis, 1 carpopedal spasm, 1 chronic alcoholism induced hypokalemia).

Benefits seen after magnesium therapy

1. Heart rate came down within an avg of 45 min, rhythm improved from irregular to regular and to good volume. 2. Urine output increased from almost oliguria to 30–40 ml/hour. Creatinine reduced or did not rise any further. 3. Pulmonary edema resolved in 24 hours. 4. Lactic acidosis disappeared with in 4–5 hours.

Discussions

1. Tachycardia induced by positive inotropes or cardiac pathology comes down to an acceptable rate when Magnesium is given in an average of 45 min. 2. Patients are protected from Tachyarrhythmia (Atrial and Ventricular arrhythmia). Incidences of drug-induced arrhythmias when Magnesium is given concomitantly with inotropes or bronchodilators are nil. 3.

Magnesium improves energy production (ATP) and stimulates metabolism. This is advantageous as patients requiring ionotropes are always in shock. 4. The affect of Magnesium therapy on Base Deficit (Lactic Acidosis) is to be studied further, because we got normal base values within 5–6 hours of Magnesium.

Figure

Graphical presentation (average heart rate).

Figure

Serum creatinine (after Mg therapy over 5 days).

Table Results after the use of magnesium in patients having different pathology

Table Inotropes (dopamine, dobutamine & noradrenaline) induced SVT after the use of magnesium