Hairy cell leukemia (HCL) 1  Is a type of blood cancer that begins in the bone marrow. 2  Is a rare type of leukemia in adults.  Hairy cell leukemia gets its name from the short, thin projections that look like hair on its cells.
In 1799 Humphrey Davy discovered anesthetic properties of nitrous oxide (N20)---also known as laughing gas.. He had recently joined Thomas Beddoesâ Pneumatic Institution (established 1798) for treatment of disease by inhalation.
The simplest anesthetic technique is to inject medications (local anesthetics) directly into the site where a procedure will be performed. This is commonly used for simple, small operations, which can be performed quickly. Advantages of local anesthesia include quick onset, minimal expense, and simplicity. In addition, a local anesthetic is most commonly administered by the surgeon, and there is no need for the services of an anesthesiologist.