William Y. Moores

Blood Conservation Techniques

Increasing numbers of operations requiring cardiopulmonary bypass have been accompanied by greater demands for blood resources. Improved techniques of blood conservation have diminished the average blood requirements per operation and have increased the percent of operations that can be done without homologous blood. The conservation of blood can be planned according to each patients requirements. The techniques include preoperative blood donation, intraoperative withdrawal of blood, reinfusion of oxygenator blood, autotransfusion of blood after heparin neutralization, autotransfusion after wound closure, and hemodilution. The availability of techniques for filtration, centrifugation, and washing of blood have improved the safety of autotransfusion. The techniques that gives the best cost/benefit ratio appear to be preoperative withdrawal of blood, reinfusion of centrifuged oxygenator contents, and reinfusion of filtered blood from chest drainage.

Theoretical analysis of oxygen transport during hypothermia.

AbstractOxygen transport and delivery to peripheral tissues during hypothermia are analyzed theoretically, taking into consideration various conditions observed both in nature and clinically. With decreasing temperature, P50 (the oxygen tension [Po2] at 50% hemoglobin saturation with oxygen) decreases, thereby leading to low mixed venous oxygen tension (

Decreased critical mixed venous oxygen tension and critical oxygen transport during induced hypothermia in pigs

P\bar vO_2

Sonomicrometry: Its Application as a Routine Monitoring Technique in Cardiac Surgery

) and thus low tissuePo2 values. On cooling from 37°C to 25°C at pH 7.4, the P50 decreases from a normal 26.8 mm Hg to 13.2 mm Hg. In the intact animal, as well as in a patient on cardiopulmonary bypass, oxygen consumption (

Oxygen transport and oxygen consumption vs. cardiac output at different haematocrits

\dot V_{O_2 }

Severe hemolytic anemia after attempted repair of paraprosthetic mitral regurgitation.

) and cardiac output (