|
|
When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.
The first documented use of surgical anesthesia in the United States was in Connecticut in 1844.
People about to have surgery must tell their health care providers about all supplements they take.
Intradermal injections are somewhat difficult to correctly administer because the skin layers are so thin that it is easy to accidentally punch through to the deeper subcutaneous layer.
It is believed that the Incas used anesthesia. Evidence supports the theory that shamans chewed cocoa leaves and drilled holes into the heads of patients (letting evil spirits escape), spitting into the wounds they made. The mixture of cocaine, saliva, and resin numbed the site enough to allow hours of drilling.