Magnesium supplementation significantly reduces serum S100beta concentrations in patients who have undergone coronary artery bypass surgery.
Magnesium (Mg) plays an important role in the prevention and treatment of central nervous system (CNS) damage. This pathology is a serious problem in patients undergoing coronary artery bypass graft surgery (CABG) with extracorporeal circulation (ECC). Its biochemical diagnosis is mainly based on S100beta protein observations. This study aims to analyse different forms of Mg supplementation on serum S100beta concentrations in patients who have undergone CABG.


METHODS
One hundred and twenty adult patients, who underwent CABG with extracorporeal circulation (ECC) with normovolemic haemodilution (NH) under general anaesthesia, were examined. According to the dose of Mg supplementation, patients were divided into six groups: A) patients receiving 3.33 mg of MgSO4 per min intravenously (i.v.), during surgery and the early postoperative period (18 hours); B) patients receiving oral Mg supplementation (OPS-Mg) and 3.33 mg of MgSO4 per min i.v., preoperatively; C) patients receiving 6.66 mg of MgSO4 per min i.v.; D) patients receiving OPS-Mg and 6.66 mg of MgSO4 per min i.v.; E) patients receiving 10 mg of MgSO4 per min i.v.; F) patients receiving OPS-Mg and 10 mg of MgSO4 per min i.v. Additionally, all patients were divided into three groups: O) patients, who did not receive dopamine or dobutamine infusion, DOP) those receiving dopamine infusion, and DOB) those receiving dobutamine infusion in doses dependent on their clinical state. Total serum Mg concentrations (Mg(t)) were measured at five time-points: 1) just before anaesthesia; 2) 10 min after ECC; 3) just after surgery, 4) in the morning of the first postoperative day, 5) in the morning of the second postoperative day.


RESULTS
ECC resulted in S100beta elevation in all patients. In groups A, B and C, S100beta increased from the second to the fourth time-points; in groups D and F, S100beta increased at the second and third time-points; and in group E, S100beta increased only at the third time-point. The highest serum S100beta concentrations were noted in groups A and B, and the lowest concentrations were noted in groups E and F. There were significant correlations between serum S100beta and Mg(t) concentrations at time-point 3 in groups A, B, C and F. Moreover, there were significant overall correlations between S100beta and Mg in groups A and B.


CONCLUSIONS
1) ECC resulted in S100beta elevation, 2) infusion of 10 mg of MgSO4 per min reduced serum S100beta concentrations, and 3) dopamine infusion resulted in the highest serum S100beta concentrations.
Dabrowski
Wojciech
W
Department of Anaesthesiology and Intensive Therapy, Feliks Skubiszewski Medical University of Lublin, Poland. wojciechdabrowski@interia.pl
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D004280:Dobutamine / Q000008:administration & dosage; D004298:Dopamine / Q000008:administration & dosage; D005112:Extracorporeal Circulation / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008274:Magnesium / Q000008:administration & dosage* / Q000097:blood; D008297:Male; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000097:blood*; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000097:blood*
D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D004280:Dobutamine; D008274:Magnesium; D004298:Dopamine