Cardiopulmonary bypass (CPB) is a critical technology in cardiac surgery, allowing for the temporary replacement of the heart and lung functions during intricate surgical procedures. it has significant post-surgical complications, the most important complications of CPB is right ventricle (RV) dysfunction. Diagnosis and management of RV dysfunction is crucial for maintenance of hemodynamic stability and organ function in early post-operation period and prognostic for later phase.
Epinephrine is the most potent adrenergic agonist which has positive inotropic and chronotropic effects and enhanced conduction in the heart (β1), smooth muscle relaxation in the vasculature and bronchial tree (β2), and vasoconstriction (α1). Low doses of this agent (\<0.1-0.2 μg/kg/min) mainly activate the β adrenoceptors with inotropic effects. Higher doses result in vasoconstrictor effect which takes the lead. Other effects include bronchial dilation, mydriasis, glycogenolysis, tachyarrhythmia, myocardial ischemia, pulmonary hypertension, hyperglycemia, and lactic acidosis. Epinephrine also reduces splanchnic and hepatic perfusion and increases metabolic workload of the liver. So this hypermetabolism that impairs oxygen exchange, glycolysis, and suppression of insulin cause lactic acidosis. Milrinone is a phosphodiesterase-III inhibitor. This effect decreases the degradation of cyclic adenosine monophosphate (cAMP), increases the cAMP levels in cells, and then increases activation of protein kinase A. Therefore, its cardiac effects are positive inotropy and improved diastolic relaxation. Milrinone also causes potent vasodilation, with reduction in preload, afterload and pulmonary vascular resistance. Considering its characteristics, milrinone might be a useful agent for cardiac surgery patients.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
102
Normal saline bolus over 10 min followed by Epinephrine intravenous infusion of 0.05-0.1 mcg/kg/min.of epinephrine 5-10 minutes before aortic unclamping
Milrinone initial bolus doses of 50 µg/kg, followed by 0.40 - 0.80 µg/kg/min of milrinone 5-10 minutes before aortic unclamping
Tricuspid annular plane systolic excursion (TAPSE) within 5 minutes post-cardiopulmonary Bypass
measured by Transesophageal echocardiography (TEE)
Time frame: within 5 mins post-cardiopulmonary bypass
Tricuspid annular plane systolic excursion (TAPSE)
measured by Transesophageal echocardiography (TEE)
Time frame: within 30-60 minutes post-cardiopulmonary bypass
Incidence of Right Ventricular Dysfunction after Cardiac Surgery
detected by ECHO when Tricuspid annular plane systolic excursion (TAPSE) ≤1.7 cm
Time frame: 24 hours postoperative
Incidence of Arrhythmias
occurrence of any Arrhythmia
Time frame: intraoperatively and 24 hours postoperative
Vasoactive-Inotrope Score (VIS)
Vasoactive-Inotrope Score = Dopamine (µg/kg/min) + Dobutamine (µg/kg/min) +100 x Epinephrine (µg/kg/min) +100 x Norepinephrine (µg/kg/min) + 10 x Milrinone (µg/kg/min) + 10,000 x Vasopressin
Time frame: recorded at 6, 12, 24, and 48 hours postoperative
Total consumption doses of Vasopressors
cumulative dose of any needed Vasopressors (Norepinepherine)
Time frame: 48 hours postoperative
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