The need for a substitute blood has been a challenge to medical practitioners for many years. Function of artificial blood is to imitate the duties of hemoglobin in red blood cells. Need for artificial blood was caused by recurrence of blood related complication during child birth, war and treatment of chronic ailments such as HIV/AIDS. There has been a reduction of blood donors, while the number of patients requiring blood transfusion has been increasing (Kresie, 2001).
Works of some medical researchers led to successful use of artificial blood. Leland C. Clark’s works reflects some of the greatest efforts. After some studies, Dr. Clark found out that alveoli had the ability to draw oxygen from fluid and replace it with carbon (iv) oxide. With this fact, he knew that perfluorocarbon can support breathing in animals. According to Pharmainfo.net (2007), Dr, Clark initiated experiments using various compounds which included per-fluorocarbons to develop a blood substitute. To establish the initial effects, he dropped a living mouse into a container with liquid fluorocarbons. During the experiment, he paralyzed the mouse in anesthesia then put a delivery tube into its trachea. Dr. Clark then inflated a cuff in the mouse’s airway so as to seal the lungs from air. He also ensured that no solution could leak out. The mouse survived even though it was fully submerged in fluorocarbon liquid. It survived because oxygen has a greater ability to dissolve in perfluorocarbon than in blood plasma.
Dr. Clark faced some challenges in his work. Although most of the animals he kept in the fluid survived for several weeks, they finally succumbed to pulmonary damage. The pulmonary damage was attributed to congestion of lungs when they were collapsed. However, research helped him realize that the lungs behave normal when they are inflated. Damage was mainly due to the size of the mouse’s airway. The physical size of the airway did not allow enough fluids to enter the lungs. As a result, carbon (iv) oxide increased in the respiratory system because it could not be removed with the same rate at which it was generated. Dr. Clark found out that the time for survival was related to the temperature of the fluorocarbon solution. Low temperatures reduced the respiratory rate while high temperature increased it. To solve this problem, he induced hypothermia in the animals in subsequent experiments. The animals used survived for over 20 hours in the fluorocarbon fluid. The temperature of the fluid used was about 18 degrees Celsius. The actual cause of the pulmonary damage was not immediately determined. It was necessary to solve all problems of pulmonary damage, carbon (iv) oxide elimination and retention of fluorocarbon in body tissues before trying it on humans.
An article in Medical Discoveries website (2007) indicates that a Japanese researcher working for a pharmaceutical firm called Green Cross, discovered that the problems facing Dr. Clark’s invention could be solved. In his experiments, the researcher mixed the fluorocarbon perfluoro-propylamine with perfluoro-dacalin. The result was a white milky solution called Fluosol. Final studies on various animals showed that Fluosol had the ability to deliver oxygen to various parts of the body when there was blockage. This ensured full blood circulation. The use of Fluosol was approved by United States Food and drug Administration. The solution is used on patients only during balloon angioplasty. In this procedure, inflated balloon cuts off blood supply to a body tissue. Fluosol is then injected to a patient to carry oxygen to the tissue which has been cut off from blood supply. Various research programs are going on to determine the toxic effects brought about by Fluosol.
References
Kresie, L. (2001). Artificial blood: an update on current red cell and platelet substitutes. Baylor University Medical Center, 2. Web.
Medical Discoveries. (2007). Artificial blood. Web.
Pharmainfo.net. (2007). Artificial Blood: A Current Review. Web.