Magnesium Usage During CABG Surgery

OBJECTIVE. Our study was performed in order to assess the effects of magnesium sulfate during coronary artery bypass surgery to evaluate whether perioperative intravenous infusion of magnesium, as an adjuvant agent for perioperative analgesia, affects a quality of anesthesia, reduces amounts of anesthetic and muscle relaxing drugs needed, affects adrenaline usage and nitroglycerine during anesthesia.

METHODS. We investigated two patient groups, undergoing a coronary artery bypass surgery. Thirty patients (control group) have not received intravenous infusion of magnesium, 31 patients (magnesium group) have received 40 mg/kg of intravenous magnesium sulfate initially and a continuous 500 mg/h infusion during anesthesia.

RESULTS. Patients in the magnesium group have received 1.01+/-0.07 mg of phentanyl, 9.33+/-0.72 mg of pipecuronium, 468+/-69 mg of tiopenthal, and 10.87+/-1.23 mg of midasolam; patients in the control group have received 1.02+/-0.07 mg of phentanyl, 10.4+/-1.2 mg of pipecuronium, 332+/-58 mg of tiopenthal and 10.4+/-1.2 mg of midasolam. Frequency of adrenaline usage in magnesium group was 6.67%, of nitroglycerine – 13.33% and nitropruside sodium – 6.67%, in control group patients have not received nitropruside sodium, frequency of adrenaline usage was 26.67% and nitroglycerine – 33.33%.

CONCLUSIONS. Perioperative intravenous infusion of magnesium, as an adjuvant agent for anesthetics, does not reduce amounts of anesthetic and relaxant drugs needed, but it stabilized blood pressure fluctuations outside the critical range, without causing the pressure fall to a level that might risk undesirable side effects during surgery.