ENHANCEMENT OF BRAIN PO(2) DURING CARDIOPULMONARY BYPASS USING A HYPEROSMOLAR OXYGEN-CARRYING SOLUTION

During the past decade a new syndrome has been recognized: cerebral hy poxia secondary to cardiopulmonary bypass, resulting in impairment of cognitive memory. The incidence of the syndrome appears to be no less that 30% in patients over 65 years of age undergoing cardiac surgery. There are several factors contributing to hypoxia produced by cardiopu lmonary bypass. One of these factors is crystalloid pump prime and rep lacement solutions devoid of (1) oxygen carrying capacity and (2) devo id of protein and its colloid osmotic pressure. This shortcoming of ca rdiopulmonary crystalloid solutions is partially responsible for two o f the three major pathologic effects of cardiopulmonary bypass: (1) hy poxia (2) interstitial fluid accumulation (anasarca, water-logging, ed ema). This report describes an oxygen carrying hyperosmolar solution w hich enhances brain pO(2) and diminishes interstitial fluid accumulati on. This blood substitute consists of perfluorcarbons and saccharides, but could consist of a hemoglobin variant plus hyperosmolar ingredien ts other than saccharides. The advantage of perfluorochemical is its a bility to access small channels and to be centrifuged off the patient post-operatively with a cell saver. The advantage of saccharides is th at they can be metabolized by the patient for energy, and they produce a moderate diuresis coming off bypass.