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Biomedical subjects

W A Lell

Publications and source records attributed to W A Lell.

31 records · Page 2Linked to original sources
PubMed1979

Hemodynamic effects of aortic clamping and decompression with a temporary shunt for resection of the descending thoracic aorta.

To assess the effects clamping of the proximal thoracic aorta and of subsequent decompression with a temporary shunt on cardiac function during resection of aneurysms of the descending thoracic aorta, mean arterial (MAP), central venous (CVP), mean pulmonary arterial (MPAP), and pulmonary capillary wedge pressures (PCWP), as well as cardiac index (CI), were measured in eight patients at baseline, 2 minutes after clamping the aorta beyond the left carotid or left subclavian artery, and 2 minutes after opening the shunt. Following clamping, MAP, CVP, and PCWP increased significantly (P less than 0.05), while CI decreased significantly, an average of 29%, and heart rate remained unchanged. After opening the shunt, all pressures returned to baseline levels. CI increased, but remained below the baseline level in seven of the eight patients (P less than 0.05). Our data indicate that significant deterioration of left ventricular performance results from clamping and that the deleterious effects can be reversed by use of a temporary shunt. They support the recommendation of proximal aortic decompression during thoracic aneurysmectomy.

Adult↗
PubMed1977

Replacement of the ascending aorta and aortic valve with a composite graft: results in 25 patients.

Our experience with combined replacement of the ascending aorta and aortic valve with a composite prosthetic valve-Dacron tube graft in 25 patients from September, 1974, to December, 1976, is reviewed. The technique involves suture of the composite graft to the aortic annulus, to the aortic tissue surrounding the coronary ostia, and to the distal ascending aorta, closing the aortic wall over the graft before discontinuing cardiopulmonary bypass. Annuloaortic ectasia was the most common indication for operation (15 patients). Perfusion of the coronary arteries was used in the first 15 patients. In the remaining 20, internal and external myocardial cooling with one period of ischemic arrest (average, 67 minutes) was used. There was 1 hospital death (4%), and there have been 3 late deaths (12%) in the 27-month follow-up period. This technique appears to be applicable to most types of aneurysmal disease of the proximal ascending aorta associated with aortic valve incompetence. All aneurysmal tissue from the aortic annulus to the innominate artery is excluded, bleeding through the graft is eliminated, operative time is reduced, and the late results have been satisfactory to date.

Adult↗
PubMedDate not supplied

Aortic valve replacement in a hemodialysis-dependent patient: anesthetic considerations--a case report.

In the anesthetic management of a hemodialysis-dependent patient undergoing aorticvalve replacement, technical and pathophysiologic problems considered included: 1. The presence of an arteriovenous hemodialysis fistula. 2. Hemodynamic alterations associated with aortic insufficiency. 3. Choice of anesthetic agents, fluid, and electrolyte balance in the presence of renal failure. 4. Postoperative management of hypertension and hyperkalemia. While there are many possible approaches, the authors present one successful technic for consideration.

Adult↗
PubMedDate not supplied

Evaluation of myocardial damage in patients undergoing coronary-artery bypass procedures with halothane-N2O anesthesia and ajuvants.

During a 6-month period in 1975, 102 patients undergoing scheduled coronary-artery bypass grafting were studied by both conventional ECG and heart-specific enzymatic methods to evaluate the incidence and estimate the extent of myocardial damage associated with an anesthetic management protocol using halothane as a primary agent with adjuvant agents. Anesthetic interventions were made to maintain heart rate and systolic pressure at resting levels or below the heart rate systolic pressure product documented during exercise-induced angina. These interventions included adjustment of halothane concentration in all patients, the use of adjuvant agents in 88.2 percent, vasodilators in 26.5 percent, and the precardiopulmonary bypass use of vasoconstrictor or cardiostimulants in 9.8 percent. There were 2 early postoperative deaths. ECG evidence of infarction was observed in 4 surviving patients. Sustained release of heart-specific CPK-MB isoenzyme occurred in 78 percent of surviving patients. Isoenzyme activity was detected in only 1 patients prior to cardiopulmonary bypass (CPB), in 1 patient during CPB, and in all others after termination of CPB. The extent of myocardial damage as estimated by integrating CPK-MB values over time was directly related to number of vessels grafted and to aortic cross-clamp and CPB times. The ECG and enzymatic data both document a low level of myocardial damage associated with this anesthetic management protocol.

Adjuvants, Anesthesia↗