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Biomedical subjects

J A Gallo

Publications and source records attributed to J A Gallo.

10 recordsLinked to original sources

Automated measurements of isolated heart muscle contractions: effects of halothane, calcium, and magnesium on guinea pig left atrial muscle.

An in vitro method for automatically measuring muscle contraction force has been demonstrated in a study of the effects of the inhalation anesthetic halothane followed by calcium chloride or magnesium sulfate on isolated guinea pig left atrial muscle. An automated computer-controlled system was used to collect muscle contraction force waveforms and to analyze contraction waveforms for comparison of variables before and after drug administration. Two concentrations of halothane (0.5 and 1.5%) were administered to the atrial preparation for 30 minutes and followed by calcium chloride or magnesium sulfate. Six variables (latency, time to peak tension, peak tension, maximum rate of change of pressure, force time integral, and relaxation time) were automatically determined from averaged stimulus-response curves. Results were normalized and compared with controls administered only calcium and magnesium and with controls administered no drugs. The automated system greatly simplified data collection and accumulation and statistical analysis of multiple responses. The system made possible averaging and analysis of more data with less variability than is normally obtained with manual systems. The results confirm several known actions of these agents. Halothane prolongs latency (9 and 21% for 0.5 and 1.5% halothane, respectively) and shortens time to peak tension (6 and 17% for 0.5 and 1.5% halothane, respectively) and relaxation time (17 and 39% for 0.5 and 1.5% halothane, respectively). At high halothane concentrations (1.5%) calcium chloride shortens latency (10%) and prolongs time to peak tension (11%); magnesium sulfate prolongs latency (14%) and shortens time to peak tension (10%).

Animals↗

Comparison of effects of atracurium and vecuronium in cardiac surgical patients.

To compare the cardiovascular effects of intubating doses of atracurium besylate and vecuronium bromide in cardiac surgical patients while utilizing fentanyl anesthesia, 20 patients scheduled for elective coronary artery bypass surgery were randomly assigned to two equal groups in a double-blind fashion. Two minutes after induction of anesthesia, baseline hemodynamic measurements were obtained and either atracurium 0.5 mg/kg (group 1) or vecuronium 0.12 mg/kg (group 2) was administered as an intravenous bolus. Hemodynamic measurements were then repeated 2, 5, and 10 minutes after injection. Atracurium produced a statistically significant decrease in blood pressure at 2 minutes and a statistically significant increase in cardiac output and decrease in systemic vascular resistance at 2, 5, and 10 minutes. Vecuronium produced no statistically significant changes in any hemodynamic variable measured other than a decrease in pulmonary capillary wedge pressure 10 minutes after the drug was administered. The hemodynamic changes seen with atracurium were closely related to changes in serum histamine levels, whereas histamine level did not change after vecuronium. There were no statistically significant differences between the two groups, even though after atracurium statistically significant changes were observed while there were no statistically significant changes associated with vecuronium. It is concluded that when utilizing the above clinical dose range, use of vecuronium may be advantageous over use of atracurium when hemodynamic stability is crucial in the anesthetic management of cardiac surgical patients.

Atracurium↗

Catecholamine anesthetic interaction in ENT surgery.

There are many crucial facets of catecholamine-volatile anesthetic interactions of which the anesthesiologist must be aware. Although still basically an excellent guideline, the recommendations originally forwarded by Katz and Katz cannot completely guide clinical actions. Many modifiers are now present, the knowledge of which will allow the anesthesiologist to provide optimum surgical conditions while still assuring maximum patient safety; the latter of which is our primary charge in the operating room.

Adolescent↗

Anesthesia for cardiac transplantation.

As the number of cardiac transplantation recipients grows, more centers will be performing cardiac transplantations and more anesthesiologists will be confronted with such patients. This chapter is intended to impart to the reader the basic knowledge necessary to manage both the donor and recipient intraoperatively. It is not intended to provide a complete description of the entire field including such areas as the surgical procedure or the immunologic theories involved. Rather, it is hoped that with the information provided, the anesthesiologist may optimally care for this patient group and perhaps become stimulated to investigate this area of medical science in more detailed sources.

Anesthesia↗

Acute effects of dobutamine and isoproterenol after implantation of a total artificial heart.

The hemodynamic effects of dobutamine and isoproterenol infusions were studied in five Holstein calves 1 day before and 2 days after the implantation of a Jarvik-7 total artificial heart (TAH). Cardiac output was decreased, and systemic vascular resistance (SVR) and pulmonary vascular resistance were increased after TAH implantation. Administration of dobutamine before TAH implantation caused an increase in heart rate, and discontinuation of dobutamine decreased cardiac output. Administration of dobutamine after TAH implantation caused decreases in mean arterial pressure and SVR. Isoproterenol increased heart rate and cardiac output and decreased SVR before TAH implantation. Isoproterenol produced no significant hemodynamic effects after TAH implantation. These results describe the hemodynamic effects that could be expected from normal clinical infusions of these drugs in the patient who is supported by the TAH as a bridge to heart transplantation; these results are of additional interest in that they describe the peripheral effects of the two agents independent of cardiac effects.

Animals↗

Surgical approach to combined coronary revascularization and abdominal aortic aneurysmectomy.

Combined repair of peripheral vascular disease and myocardial revascularization has become accepted treatment in selected patients. Two of our patients underwent such a procedure. One patient suffered an intraoperative dissection of the ascending aorta following myocardial revascularization. Ascending aortic replacement and vein graft reimplantation was accomplished as well as repair of the abdominal aortic aneurysm. Because of this experience we recommend that following myocardial revascularization, aortic cannulation be maintained during repair of the abdominal aortic aneurysm. This allows immediate access to cardiopulmonary bypass should untoward cardiovascular events occur during aneurysm repair.

Aged↗