SATISH KUMAR MISHRA

Objective: To evaluate the effect of intravenous magnesium sulfate on post-operative complications when given prophylactically while coming of cardio pulmonary bypass (CPB) in patients undergoing cardiac surgery. Methodology: A double-blinded randomized studyconducted at a tertiary care center in western Maharashtra from Nov 2017 to April 2019. Patients were divided into two groups. Group A (Magnesium sulfate group) (n=130) & Group B (control group) (n=130). Patients undergoing on pump Coronary artery bypass grafting (CABG), Mitral valve replacement/repair (MVR), Aortic Valve Replacement (AVR) or both AVR & MVR (DVR) on CPB were included in the study.Once surgery was over, aortic cross clamp taken out & temperature of 36°c was attained, Group A patients received Injection Magnesium sulfate 1 gm IV slowly over 10 minutes.Patients were monitored for heart rate, intra-arterial blood pressure oxygen saturation, continuous electrocardiograph with automatic ST segment analysis apart from this ECG mapping was done. Results:There was no significant Statistical difference regarding the demographic data, comorbidities & ejection fraction between the two groups. The result shows a statistically significant difference (P=0.032) between the two groups with regards to the incidence of atrial fibrillation. In group A 10 patients (7.70%) had atrial fibrillation compared to group B where 28 patients (21.6%) had atrial fibrillation.Weaning from CPB was easier in group A patient compared to group B & also group A patient needed smaller doses of pharmalogical support, than group B. Conclusion: A single bolus 1Gm dose of magnesium sulfate while coming off from CPB has an excellent effect in reducing the incidence of atrial fibrillation. Further magnesium reduced the amount of pharmacological support which was required to come off CPB.

ABSTRACT Milrinone is commonly used during cardiac surgeries to decrease pulmonary arterial pressure. When it is used in inotropic doses it decreases systemic vascular resistance (SVR) and leads to systemic vascular hypotension. This may lead to initiation of vasoconstrictor drugs such as nor-adrenaline, vasopressin or terlipressin. The aim of the present study was to evaluate and compare the effect of vasopressin versus terlipressin in prevention of milrinone induced hypotension and to see the effect on pulmonary vascular resistance. After obtaining informed written consent & approval of ethics & research committee patients who were scheduled for mitral valve replacements (MVR), Aortic valve replacement (AVR), or Dual valve replacement (DVR) with pulmonary arterial hypertension (PAH) were included in the study. Patients were divided into two groups randomly by using a computer generated randomized block design namely group A (n=20) Terlipressin group & group B (n=20) vasopressin group. 10 minutes after initiation of milirinone after rewarming and weaning from CPB group A patients were started on terlipressin infusion at a rate of 2ug/kg/hr & group B patients were started on vasopressin infusion at a rate of 0.02u/min. Infusions in both the groups were continued for 24 hrs in the post-operative period. Hemodynamic measurements were taken at induction of anesthesia, 10 min after start of milrinone infusion, at the end of surgery before shifting the patient to ICU. In the post-operative period these hemodynamic parameters were measured every 6 hourly in the first 24 hrs. At baseline both the systemic & pulmonary hemodynamic variables were similar in both the groups after the induction of anesthesia, 10 minutes after the initiation of milrinone injection the mean arterial pressure in group A decreased from 77.56± 4.5 to 53.21±2.1 & in group b it decreased from 76.46±3.3 to 52.11±1.1 (p≤0.05) which was statistically significant in both groups 10 min after initiation of milrinone which was statistically significant (p≤0.05). When the duration of mechanical ventilation, duration of ICU stay and duration of hospital stay were compared between the two groups there was no significant statistical difference between the groups From our study we concluded that when terlipressin is used to treat milrinone induced hypotension it reverses the systemic hypotension with lesser effect on pulmonary vascular resistance when compared to vasopressin Keywords: SVR: systemic vascular resistance, PVR: Pulmonary vascular resistance, MVR: mitral valve replacement, AVR: Aortic valve replacement, DVR: Dual valve replacement PAH: pulmonary arterial hypertension