Snake venom may contain nerve poisons, blood poisons and muscle destroying poisons. Nerve poisons may cause paralysis, stopping the individual from breathing by blocking the nerve signals transmitted from the nervous system to the muscles that control the lungs and diaphragm. sometimes no antivenin is used. The patient need to be kept alive on a breathing machine until the nerve poison dissipates. A blood transfusion would not work to remove the nerve poison. Blood transfusion would not stop the toxins that destroy muscle tissues either. blood transfusion may help if the snake venom destroys red blood cells, but snakes that have venom that attack the blood cells may also have other kinds of toxins that attack other bodily functions. If antivenin is not available, the chance of survival is much reduced, and even if a victim survives, the chance of permanent damage, e.g. missing muscle tissue, is high.