Bloodless Arterial Switch Operation in a 2.7-kg Jehovah's Witness Patient.

Bloodless pediatric cardiac surgery requiring the use of cardiopulmonary bypass (CPB) remains a challenge for the entire operating room (OR) team. The amount of circulating blood volume to pump prime volume mismatch of small patients results in hemodilution that frequently results in transfusion of allogeneic blood products. Patients of families of the Jehovah's Witness (JW) faith reject the use of these products because of religious beliefs. Our institution is a referral center for children of JW families because we have developed techniques to minimize blood loss with the hope of performing bloodless pediatric cardiac surgery whenever possible. These techniques include preoperative treatment with erythropoietin, intraoperative acute normovolemic hemodilution, CPB circuit miniaturization, ultrafiltration during and after CPB, limiting blood gas analyses or other unnecessary blood draws, and using hemostatic agents during and after CPB. We present the case of a 4-day-old patient of the JW faith weighing 2.7 kg with transposition of the great arteries and an intact ventricular septum who underwent an arterial switch operation. The patient received no allogeneic blood product administration throughout the entire hospitalization. The patient's first hematocrit in the OR was 43%, lowest hematocrit on bypass was 15%, and first hematocrit in the cardiothoracic intensive care unit post-procedure was 21%. The patient was discharged on post-op day nine with a hematocrit of 36%.

Enhanced ionic conductivity in electroceramics by nanoscale enrichment of grain boundaries with high solute concentration.

The enhancement of oxygen ionic conductivity by over two orders of magnitude in an electroceramic oxide is explicitly shown to result from nanoscale enrichment of a grain boundary layer or complexion with high solute concentration. A series of CaxCe1-xO2-δ polycrystalline oxides with fluorite structure and varying nominal Ca2+ solute concentration elucidates how local grain boundary composition, rather than structural grain boundary character, primarily regulates ionic conductivity. A correlation between high grain boundary solute concentration above ∼40 mol%, and four orders of magnitude increase in grain boundary conductivity is explicitly shown. A correlated experimental approach provides unique insights into fundamental grain boundary science, and highlights how novel aspects of nanoscale grain boundary design may be employed to control ion transport properties in electroceramics.