Journal of cardiothoracic and vascular anesthesia
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J. Cardiothorac. Vasc. Anesth. · Aug 1993
ReviewMyocardial dysfunction following cardiopulmonary bypass: recovery patterns, predictors of inotropic need, theoretical concepts of inotropic administration.
Clinical myocardial dysfunction following cardiopulmonary bypass commonly occurs in patients with good preoperative ventricular function. Following separation from cardiopulmonary bypass, ventricular function improves initially, but then begins to worsen and reaches a nadir between 4 and 6 hours after surgery with full recovery occurring around 24 hours postoperatively. However, in patients with preoperative ventricular dysfunction, the depression of ventricular function is more severe and recovery is longer. ⋯ This diminishes the effectiveness of agents dependent on cAMP to produce an inotropic response. However, amplification of the reduced cAMP produced by beta-agonists may occur in association with the inhibition of cAMP breakdown resulting from phosphodiesterase inhibitors. All inotropic agents are usually effective in reversing the reperfusion-induced stunned myocardium.(ABSTRACT TRUNCATED AT 250 WORDS)
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J. Cardiothorac. Vasc. Anesth. · Aug 1993
ReviewSupport of the perioperative failing heart with preexisting ventricular dysfunction: currently available options.
Perioperative support of the patient with preexisting biventricular failure requires simultaneous optimal manipulation of heart rate and rhythm, loading conditions, and contractility. Patients with preexisting ventricular dysfunction will have alterations in beta-adrenergic receptors, resulting in decreased responsiveness to catecholamines. Even patients with previously normal ventricular function can develop ventricular dysfunction caused by reperfusion injury and other potentially damaging effects of extracorporeal circulation. ⋯ When administered in combination, catecholamine and cyclic-AMP-specific phosphodiesterase inhibitors can have additive effects to restore beta 1-adrenergic responsiveness. Combination therapy provides an important therapeutic option to facilitate separation from cardiopulmonary bypass. Pharmacologic intervention for right ventricular dysfunction focuses on reversal of pulmonary vasoconstriction with nitrates, beta 2-adrenergic agents, phosphodiesterase inhibitors and prostaglandin E1.
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J. Cardiothorac. Vasc. Anesth. · Jun 1993
Randomized Controlled Trial Comparative Study Clinical TrialMidazolam and fentanyl continuous infusion anesthesia for cardiac surgery: a comparison of computer-assisted versus manual infusion systems.
Continuous infusion of intravenous anesthetics can be achieved either by a manually controlled infusion (MCI) pump, or by a computer-assisted continuous infusion (CACI) pharmacokinetic model-driven infusion system. Randomized double-blind comparisons of the two infusion systems for general anesthesia were performed in 24 patients undergoing coronary artery bypass grafting. Patients were allocated to receive continuous infusions of midazolam and fentanyl by either a MCI device or CACI. ⋯ The drug levels were lower (P < or = .05) for midazolam during maintenance of anesthesia and similar for fentanyl during the maintenance of anesthesia. In the MCI group, the average duration of anesthesia was 246.5 +/- 35.0 minutes, with a mean total fentanyl dose of 30.27 +/- 11.14 micrograms/kg. In the CACI group, the average duration of anesthesia was 230.8 +/- 44.1 minutes, with a mean total fentanyl dose of 34.61 +/- 5.40 micrograms/kg (P > 0.05 for comparisons between groups for duration of anesthesia and total fentanyl dose).(ABSTRACT TRUNCATED AT 250 WORDS)
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J. Cardiothorac. Vasc. Anesth. · Jun 1993
Comparative StudyComparison of axillary artery or brachial artery pressure with aortic pressure after cardiopulmonary bypass using a long radial artery catheter.
Arterial pressure measured in a peripheral artery may significantly underestimate central arterial pressure after discontinuation of cardiopulmonary bypass (CPB). Arterial pressure measured with a 50 cm radial artery catheter advanced into the brachial or axillary artery was compared to ascending aortic pressure in 31 patients before and after discontinuation of CPB. The radial artery catheter extended proximally into the brachial artery in 8/31 patients, and into the axillary artery in 23/31 patients. ⋯ The average aorta-to-brachial artery systolic pressure gradient was 6.9 +/- 6.9 mmHg, with 3/8 patients having a gradient greater than 10 mmHg. Long radial artery catheters, placed using the Seldinger technique, provide an accurate estimate of central aortic pressure after CPB when they are advanced into the axillary artery. Sites more distal than the axillary artery may result in significant underestimation of the central aortic pressure in these patients.