Hemodynamic and Renal Effects of Dopexamine and Dobutamine in Patients With Reduced Cardiac Output Following Coronary Artery Bypass Grafting: Materials

Hemodynamic and Renal Effects of Dopexamine and Dobutamine in Patients With Reduced Cardiac Output Following Coronary Artery Bypass Grafting: MaterialsIncremental doses of 1 or 3 ^g/kg/min of dopexamine and 2.5 or 7.5 /ug/kg/min of dobutamine were used if the patient could not tolerate the stated dosages. During the intensive care unit (ICU) maintenance phase of the study (from 1 h after starting the study drug to the end of the 24-h study period), adjustment of drug dosages was titrated only if Cl fell below 3.0 L/min/m2 or if sustained tachycardia (heart rate [HR] >120 beats/min) occurred. Fluids (6 percent hetastarch or 5 percent albumin) were given to keep PCWP >10. Drug preparation was performed in the pharmacy and the drugs were assigned randomly in a double-blinded manner so that the patients and all members of the clinical care team were blinded to the medication being infused this natural asthma treatment. Hemodynamic variables (including HR, cardiac output, pulmonary artery pressure and PCWP, and mean arterial pressure [MAP]) were measured at 5-and 10-min intervals for the 30 min after the initial drug administration, then hourly for the next 8 h after bypass, then every 2 h for the remainder of the study period. Serum electrolytes, urine volume, and urinary sodium excretion were also measured at defined times during the study. Electrocardiograms were obtained at the beginning of the study period, at 6 h, and again at the end of the study period.
Sustained supraventricular tachycardia (including sinus tachycardia), defined as HR >120 beats/min for greater than 10 min, was first addressed by decreasing the dose of the study drug to the next lower incremental dose. If the tachycardia persisted after 15 min on the adjusted dose, the patients were then treated with intravenous esmolol at doses adequate to maintain HR <105 beats per min (initial infusion rate 50 /ug/kg/min; maintenance doses ranging from 25 to 400 /ug/kg/min). Heart rates below 90 beats/min were treated with an epicardial lead pacemaker at the discretion of the cardiac surgeon. Ventricular ectopy was treated with intravenous lidocaine.

This entry was posted in Cardiac Surgery and tagged Cardiac surgery (CABG), dobutamine, dopexamine, inotropic support (inotropy).