Spinal Anesthesia is also called as spinal block, subarachnoid Block (SAB), intradural block and intrathecal block. It is a form of regional anesthesia used to induce anesthesia by blocking the cluster of spinal nerves. These spinal nerves are connected to brain and induce pain signals throughout the body. Anesthetics are intravenously administered in the cerebrospinal fluid to achieve the stage of anesthesia.