Blood substitutes

Blood substitutes, often called artificial blood, are used to fill fluid volume and/or carry oxygen and other blood gases in the cardiovascular system. Although commonly used, the term is not accurate since human blood performs many important functions. Red blood cells transport oxygen, white blood cells defend against disease, platelets promote clotting, and plasma proteins provide various functions. The preferred and more accurate terms are volume expanders for inert products, and oxygen therapeutics for oxygen-carrying products. Examples of these two "blood substitute" categories: Volume expanders: inert and merely increase blood volume. These may be crystalloid-based (Ringer's lactate, normal saline, D5W (dextrose 5% in water) or colloid-based (Haemaccel, Gelofusin). Oxygen therapeutics: mimic human blood's oxygen transport ability. Examples: Hemopure, Oxygent, PolyHeme. Oxygen therapeutics are in turn broken into two categories based on transport mechanism: perfluorocarbon based, and hemoglobin based. Volume expanders are widely available and are used in both hospitals and first response situations by paramedics and emergency medical technicians. Oxygen therapeutics are in clinical trials in the U.S. and Europe, however Hemopure is more widely available in South Africa.