Journal of cardiothoracic and vascular anesthesia
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J. Cardiothorac. Vasc. Anesth. · Jun 1992
ReviewAlpha 2-adrenergic agonists in cardiovascular anesthesia.
At this time, the unique attributes of alpha 2-agonists in anesthesia lie in their ability to blunt the adrenergic response to the stresses of major surgery, in patients in whom this response is especially undesirable, without incurring the penalty of respiratory depression that attends the use of opioids. It has become more and more apparent that sympathetic/adrenergic activation often has adverse consequences for patient morbidity and mortality, and modification of such activation by drugs may be a valuable option for the anesthesiologist. However, at present, the evidence supporting this statement is "soft," such as improved hemodynamic and metabolic stability. ⋯ In these cases, it is not the choice of a specific anesthetic agent or technique, but rather the competence and diligence of the anesthesiologist that is most important for outcome. In contrast, in major cardiovascular surgery in high-risk patients, the optimal anesthetic approach attains more importance, and is still undecided. The final consensus as to whether or not this optimal approach will include the use of alpha 2-adrenergic agonists will depend on the results of more extensive clinical investigations.
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J. Cardiothorac. Vasc. Anesth. · Jun 1992
Continuous thermodilution cardiac output measurement in intensive care unit patients.
A new continuous thermodilution cardiac output measurement technique and companion flow-directed pulmonary artery catheter were evaluated in intensive care unit (ICU) patients. Continuous cardiac output was monitored for 6 hours in each patient, and, at selected intervals, a series of bolus thermodilution cardiac output determinations was made and averaged for comparison. A total of 222 data pairs was obtained in 54 patients. ⋯ The mean relative error was 0.3%, and the standard deviation of the relative error was 11.5%. The absolute measurement bias was 0.02 L, and the 95% confidence limits were 1.07 and -1.03 L. The results demonstrated that the new continuous thermodilution cardiac output measurement technique provided acceptable accuracy and was considerably easier to use in the clinical situations studied in the ICU.
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J. Cardiothorac. Vasc. Anesth. · Jun 1992
Right ventricular function in patients with aortic stenosis undergoing aortic valve replacement.
The effects of aortic stenosis (AS) on right ventricular function during cardiac surgery are not fully understood. Forty patients undergoing aortic valve replacement with either a systolic transvalvular gradient of less than 100 mm Hg (82.1 +/- 5.5 mm Hg; group 1, n = 20) or greater than 120 mm Hg (131.1 +/- 6.9 mm Hg, group 2, n = 20) were investigated with regard to right ventricular function in the perioperative period. Right ventricular ejection fraction (RVEF), right ventricular end-systolic volume (RVESV), and right ventricular end-diastolic volume (RVEDV) were measured by means of the thermodilution technique. ⋯ In these patients more epinephrine was necessary to maintain stable hemodynamics during the post-bypass period. It is concluded that patients with AS are at risk of reduced right ventricular function when the systolic transvalvular pressure gradient is more than 120 mmHg. Knowledge of the complex interaction between the two sides of the heart may enable anesthesiologists to optimize management during the perioperative period.