A Comparative Study Between Vasopressin Versus Terlipressin In Prevention Of Milrinone Induced Hypotension In Patient Undergoing Cardiac Surgery.

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