Oxygen therapeutics (blood substitutes) in cardiac surgery

Abstract

Discuss and summarize recent published literature related to the use of 'blood substitutes' in cardiac surgery patients. Concerns about safety, inventory and the cost of allogenic blood transfusion have led to the continued interest to find an ideal oxygen carrier 'blood substitute' for cardiac surgery patients. Two classes of oxygen therapeutics 'blood substitutes' are being investigated: (1) perfluorocarbons are synthetic fluorinated hydrocarbons which increase dissolved oxygen in the fluid phase and (2) hemoglobin-based oxygen carriers, modified to improve oxygen dissociation properties and side effects profiles of free hemoglobin. Hemoglobin-based oxygen carriers from bovine and human sources are being tested in phase III trials in cardiac surgery patients as well as a variety of other surgical and nonsurgical settings. Recombinant human hemoglobin and encapsulated hemoglobins of any source are emerging. Safety and cost effectiveness are being evaluated for their use as an alternative to blood transfusion or along with other strategies of blood conservation in cardiac surgery. One hemoglobin-based oxygen carrier (Hemopure) has been approved for use in humans in South Africa as well as another hemoglobin-based oxygen carrier (Gelenpol) and a perfluorocarbon (Perfluoron) in Russia. Phase III trials in Europe and North America will be concluded very soon. We anticipate seeing one or two products approved in North America and Europe by the year 2003/2004.