Cardiogenic Shock Case Study

Cardiogenic shock is associated with inadequate tissue perfusion that can cause cardiac failure, usually causing acute myocardial infarctions .RG is a 68-year-old man that has been admitted to the ICU after undergoing coronary artery bypass grafting. He has been diagnosed with history of ischaemic heart disease with two previous myocardial infarctions, hypertension and hypercholesterolaemia which he has been on maintenance therapy. He has been administered with dopamine at 3 mcg/kg/minute and titrated to 8 mcg/kg/minute during the next 2 hours . However, the doctor in charge suggested to replace dopamine with dobutamine as RG has history of myocardial infarction. Cardiac failure in patients with cardiogenic shock occurs due to myocardial infarctions that cause inadequate tissue perfusion due to impaired delivery of oxygen and nutrient to the heart that can lead to hypotension and multi-organ

Dopamine acts on B1 receptor in renal by increasing perfusion of blood to kidney due to vasodilation of renal vessel and able to maintain kidney function. Dopamine also has lower tendency than noradrenaline and adrenaline to cause vasoconstriction of cutaneous, renal and possibly other vessels. Dopamine also activates both dopaminergic and adrenergic receptors depending on its concentrations. It has dose dependent effect. At low concentration, dopamine cause dilation of renal, mesenteric and coronary vessels that increased blood flow to these tissue. At intermediate doses, dopamine acts on β1 receptor by releasing noradrenaline from nerve terminal and cause inotropic effect and possibly little chronatropic effect. Increase force of cardiac contraction will increase oxygen consumption and able to reduce coronary vascular resistance. At high dose, dopamine stimulates α1 receptor and cause general