A patient named RG has ischaemic heart disease with two previous myocardial infarctions (MIs) is admitted to ICU after undergoing coronary artery bypass grafting. After surgery, his preoperative ejection fraction was 45%. He also has controlled hypertension and hypercholesterolaemia. He needs mechanical ventilation and pulmonary artery catheter in place. His blood pressure and urine output have fallen after one hour admission to the ICU. He has no signs of ischaemia, tamponade and acute MI. He is tachycardic, having mild pulmonary oedema, RG is diagnosed to have cardiogenic shock because he had shown the pathophysiology of cardiogenic shock. He had shown decrease in cardiac output and low organ perfusion. Decrease in cardiac output will subsequently
…show more content…
The dose given at 3mcg/kg/min which is in the range of 1-5 mcg/kg/min IV (low dose) may increase urine output and renal blood flow. 8mcg/kg/min is in the range of 5-15 mcg/kg/min IV (medium dose) may increase renal blood flow, cardiac output, heart rate, and cardiac contractitlity. Duration of onset is 5 min while duration of absorption is less than 10 minutes. Volume of distribution is 1.8 to 2.45L/kg. Dopamine is metabolized in liver, kidney, and plasma by monoamine oxidase and catechol-O-methyl transferase, convert it into active norepinephrine and inactive metabolites. The half-life of dopamine is 2 minutes and total body clearance is 115 mL/kg/min. 80% of it will be excreted in …show more content…
However, dobutamine is less arrhythmogenic and produces less tachycardia compared to dopamine. Dobutamine also has comparatively little effect on aortic pressure. The patient already suffering from tachycardia, if dopamine is given, it will only worsen the condition. Dobutamine provides strong β1 and weak β2 effects which resulting in increased cardiac output, blood pressure, and heart rate. The suggested dose is 2-20 mcg/kg/min IV or IO, and it can be titrated to desired effect but should not to exceed 40 mcg/kg/min because high dose may cause an increase in heart rate, exacerbating myocardial ischemia. Duration of onset is 1-10minutes which is longer than dopamine while duration of action is 10min which take longer time compared to dopamine. It needs up to 15munites to peak. Volume of distribution for dobutamine is 0.2 L/kg. Dobutamine metabolized in tissues and liver by catechol-O-methyl transferase and produce glucuronide conjugate and inactive 3-0-methylated dobutamine. Half-life of dobutamine is 2 minutes while the clearance is 90 mL/kg/min. It is also excreted in
The dose given at 3mcg/kg/min which is in the range of 1-5 mcg/kg/min IV (low dose) may increase urine output and renal blood flow. 8mcg/kg/min is in the range of 5-15 mcg/kg/min IV (medium dose) may increase renal blood flow, cardiac output, heart rate, and cardiac contractitlity. Duration of onset is 5 min while duration of absorption is less than 10 minutes. Volume of distribution is 1.8 to 2.45L/kg. Dopamine is metabolized in liver, kidney, and plasma by monoamine oxidase and catechol-O-methyl transferase, convert it into active norepinephrine and inactive metabolites. The half-life of dopamine is 2 minutes and total body clearance is 115 mL/kg/min. 80% of it will be excreted in …show more content…
However, dobutamine is less arrhythmogenic and produces less tachycardia compared to dopamine. Dobutamine also has comparatively little effect on aortic pressure. The patient already suffering from tachycardia, if dopamine is given, it will only worsen the condition. Dobutamine provides strong β1 and weak β2 effects which resulting in increased cardiac output, blood pressure, and heart rate. The suggested dose is 2-20 mcg/kg/min IV or IO, and it can be titrated to desired effect but should not to exceed 40 mcg/kg/min because high dose may cause an increase in heart rate, exacerbating myocardial ischemia. Duration of onset is 1-10minutes which is longer than dopamine while duration of action is 10min which take longer time compared to dopamine. It needs up to 15munites to peak. Volume of distribution for dobutamine is 0.2 L/kg. Dobutamine metabolized in tissues and liver by catechol-O-methyl transferase and produce glucuronide conjugate and inactive 3-0-methylated dobutamine. Half-life of dobutamine is 2 minutes while the clearance is 90 mL/kg/min. It is also excreted in