Journal of cardiothoracic and vascular anesthesia
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J. Cardiothorac. Vasc. Anesth. · Oct 1992
Randomized Controlled Trial Comparative Study Clinical TrialAmrinone and dobutamine as primary treatment of low cardiac output syndrome following coronary artery surgery: a comparison of their effects on hemodynamics and outcome.
This study was undertaken in order to compare the effectiveness of amrinone and dobutamine as primary treatment of a low cardiac output (CO) after coronary artery bypass graft (CABG) surgery. Thirty patients with preoperative left ventricular dysfunction participated in this open-label randomized study. Patients were included if they failed to separate from cardiopulmonary bypass (CPB) without inotropic support or if they had a cardiac index (CI) less than 2.4 L/min/m2 after CPB regardless of the blood pressure, in the presence of adequate filling pressures. ⋯ Six dobutamine patients (40%) had postoperative myocardial infarction (MI) as opposed to none among the amrinone patients (P = 0.017). These results indicate that amrinone compares favorably with dobutamine as a primary treatment of low CO after CABG. Further study in a larger number of patients will be required in order to determine if the lower incidence of MI in the amrinone group was due to the treatment drug.
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J. Cardiothorac. Vasc. Anesth. · Oct 1992
Left ventricular filling as assessed by pulsed Doppler echocardiography after coronary artery bypass grafting.
Diastolic filling of the left ventricle, as assessed by transesophageal pulsed Doppler echocardiography during and in the early phase following coronary artery bypass grafting, was investigated in nine patients without valvular disease or left ventricular hypertrophy. The ratio between the maximal heights of the early diastolic flow-velocity peak and the late (atrial) diastolic flow-velocity peak, the E:A ratio, and also the deceleration time of the early peak were calculated as indices of left ventricular filling. The E:A ratio decreased from 1.01 +/- 0.06 after induction of anesthesia to 0.46 +/- 0.06 on arrival in the intensive care unit (ICU). ⋯ In the ICU, pulmonary capillary wedge pressure remained unchanged, heart rate decreased by approximately 12%, and systemic vascular resistance decreased by approximately 40%. The changes in hemodynamic parameters could have affected the E:A ratio, but it is unlikely that they could explain the marked increase in the E:A ratio that occurred in the ICU. The results, therefore, imply the presence of impaired diastolic filling immediately after cardiopulmonary bypass with gradual, but not complete, recovery during the first 6 hours in the ICU.
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J. Cardiothorac. Vasc. Anesth. · Oct 1992
Multicenter Study Clinical TrialIntravenous milrinone following cardiac surgery: II. Influence of baseline hemodynamics and patient factors on therapeutic response. The European Milrinone Multicentre Trial Group.
Further analysis of the data from 99 adult patients who received an intravenous infusion of milrinone following elective cardiac surgery was done. All patients received a bolus infusion of 50 micrograms/kg over 10 minutes, followed by a maintenance infusion of either 0.375, 0.5 or 0.75 microgram/kg/min for a period of 12 hours. Hemodynamic measurements were made after the bolus infusion (15 minutes), and then after 30, 45, and 60 minutes at 3, 6, and 12 hours, and 4 hours after treatment was stopped. ⋯ Patients with a low CI (1.59 L/min/m2) had a 54% increase after the bolus infusion compared to a 27% increase in patients with a higher pretreatment value (2.2 L/min/m2) (P < 0.05); (2) patients with a high resting level of pulmonary vascular resistance (PVR > 200 dynes.sec.cm-5) had a greater response to treatment (26% fall in PVR) than the remainder (9% fall in PVR) after 60 minutes; (3) patients with a low pretreatment mean arterial pressure (MAP) (n = 17, MAP 64 mmMg, range, 52 to 70) showed no fall in MAP following treatment, but showed a significant increase in CI (+55%). A good therapeutic response was found that was similar in patients undergoing valve replacement surgery or coronary artery bypass graft surgery, and in patients in sinus rhythm or atrial fibrillation before treatment. It is concluded that the therapeutic response to intravenous milrinone following cardiac surgery is partially determined by pretreatment hemodynamics.
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J. Cardiothorac. Vasc. Anesth. · Oct 1992
Dobutamine increases heart rate more than epinephrine in patients recovering from aortocoronary bypass surgery.
To determine whether epinephrine might prove to be a cost-effective substitute for dobutamine, two 8-minute infusions of either epinephrine (10 and 30 ng/kg/min, n = 28) or dobutamine (2.5 and 5 micrograms/kg/min, n = 24) were administered to 52 patients recovering in the intensive care unit (ICU) after aortocoronary bypass (CABG) surgery. At the higher dose, both drugs significantly (P < .05) increased cardiac index (CI), epinephrine from 2.8 +/- 0.1 at baseline to 3.3 +/- 0.1 L/min/m2, and dobutamine from 3.2 +/- 0.1 at baseline to 4.1 +/- 0.2 L/min/m2. Epinephrine increased CI significantly less than dobutamine. ⋯ On the other hand, while the higher dose of both drugs significantly increased heart rate (HR), epinephrine from 88 +/- 2 at baseline to 90 +/- 2 beats/min and dobutamine from 89 +/- 2 at baseline to 105 +/- 3 beats/min, the increase following the higher dose of dobutamine was significantly greater than that seen after epinephrine. Effects of the two drugs on mean arterial pressure, central venous pressure, pulmonary artery occlusion pressure, systemic vascular resistance, pulmonary vascular resistance, and left-ventricular stroke work did not significantly differ. Similar results were obtained in the subset of patients with baseline CI less than 3 L/min/m2 who more closely resembled patients who might acutely require inotropic drug administration.(ABSTRACT TRUNCATED AT 250 WORDS)