Roe E. Wells

Syndromes of Hyperviscosity

THE use of syndromes to describe complex lists of symptoms and signs represents a convenient economy of scientific expression. The state of serum hyperviscosity, which involves spontaneous bleeding...

Rheology of Blood in the Microvasculature

THE flow of blood through the microvasculature is as vital to life as that through the heart and great vessels. Vasomotor control of the circulation is accomplished principally in the arteriolar ve...

Influence of a defoaming agent upon the hematological complications of pump oxygenators.

Measurements of plasma hemoglobin values were made at many different sites of a Cross-Kay disk pump oxygenator during extracorporeal bypass in patients undergoing reparative valve surgery. Hemoglobin values were always higher in the line of the aspirator and defoaming chamber than in any other part of the system. Sampling immediately proximal and distal to the defoaming chamber revealed significant increases in plasma hemoglobin values as a result of the defoaming process.Studies of the hematological effects of the defoaming agent, polymethylsiloxane, which coats the disposable stainless steel sponge in the defoaming chamber, showed it greatly reduced the resistance of red cells to lysis by mechanical trauma. Similar studies of plasma showed the hemolytic effects of the defoaming agent are to some extent mediated by the plasma.It is concluded that the widely used defoaming agent, polymethylsiloxane, contributes to the hemolytic action of the bubbling, suctioning, and defoaming processes during open heart surgery. The addition of a water soluble surfactant material, that stabilizes emulsions (Pluronic F68), blocked or prevented the hemolytic process without interfering with the action of the antifoam material.

A CLINICAL, PHYSIOLOGIC AND PSYCHOLOGIC STUDY OF 20 GERIATRIC CLINIC PATIENTS

Excerpt The establishment of the Pearl Geriatric Clinic at the Peter Bent Brigham Hospital promoted a focus of interest on the ambulatory elderly patient within a separate clinic activity. At the o...