title: Magnesium substitution in elective coronary artery surgery: a double-blind clinical study.
abstract: Magnesium may be beneficial in the control of ventricular ectopy and supraventricular tachyarrhythmias after coronary artery bypass graft (CABG) surgery, but it is not known whether a high-dose magnesium regimen is superior to a regimen keeping the patient normomagnesemic. A prospective randomized and double-blind clinical comparison was performed in 81 elective CABG patients in order to assess the effects of two different magnesium infusion regimens on electrolyte balance and postoperative arrhythmias. Forty-one patients (high-dose group, H) received 4.2 +/- 0.7 g (mean +/- SD), of magnesium sulfate before cardiopulmonary bypass, followed by an infusion of 11.9 +/- 2.8 g of magnesium chloride until the first postoperative (PO) morning, and a further 5.5 +/- 1.0 g until the second PO morning. Forty patients (low-dose group, L) received magnesium sulfate only after bypass to a total of 2.9 +/- 0.5 g at the first, and 1.4 +/- 0.1 g at the second PO morning. A blood cardioplegia technique was used in both groups, including bolus doses of magnesium chloride to a total of 2.4 +/- 0.6 g and 2.3 +/- 0.6 g to H and L patients, respectively. Continuous Holter tape-recording was used for 12 to 15 hours preoperatively, and for 48 hours postoperatively. Serum magnesium peaked in H patients on the first PO morning at 1.60 +/- 0.25 mmol/L, whereafter it declined to the normal level on the third PO morning. Patients in the L group were normomagnesemic, except after the start of bypass.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Anesthesiology, Oulu University Central Hospital, Finland.
authors.forename: J O
authors.initials: JO
authors.lastname: Wistbacka
authors.forename: J
authors.initials: J
authors.lastname: Koistinen
authors.forename: K E
authors.initials: KE
authors.lastname: Karlqvist
authors.forename: M V
authors.initials: MV
authors.lastname: Lepojärvi
authors.forename: R
authors.initials: R
authors.lastname: Hanhela
authors.forename: J
authors.initials: J
authors.lastname: Laurila
authors.forename: J
authors.initials: J
authors.lastname: Nissinen
authors.forename: R
authors.initials: R
authors.lastname: Pokela
authors.forename: E
authors.initials: E
authors.lastname: Salmela
authors.forename: A
authors.initials: A
authors.lastname: Ruokonen
mesh_terms: D001145:Arrhythmias, Cardiac / Q000517:prevention & control*; D001281:Atrial Fibrillation / Q000517:prevention & control; D002118:Calcium / Q000097:blood; D005117:Cardiac Complexes, Premature / Q000517:prevention & control; D001026:Coronary Artery Bypass; D003402:Creatine Kinase / Q000097:blood; D004311:Double-Blind Method; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007527:Isoenzymes; D008274:Magnesium / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D015636:Magnesium Chloride / Q000008:administration & dosage / Q000627:therapeutic use; D008278:Magnesium Sulfate / Q000008:administration & dosage / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D011446:Prospective Studies; D013617:Tachycardia, Supraventricular / Q000517:prevention & control; D014693:Ventricular Fibrillation / Q000517:prevention & control
chemical_list: D007527:Isoenzymes; D015636:Magnesium Chloride; D008278:Magnesium Sulfate; D003402:Creatine Kinase; D008274:Magnesium; D002118:Calcium