Spinal anaesthesia (or spinal anesthesia), also called spinal block, subarachnoid block, intradural block, and therefore the intrathecal block may be a sort of neuraxial regional anesthesia involving the injection of an area anaesthetic or opioid into space, generally through a fine needle, usually 9 cm (3.5 in) long. It is a secure and effective sort of anesthesia performed by nurse anesthetists and anesthesiologists which may be used as an alternative to general anaesthesia commonly in surgeries involving the lower extremities and surgeries below the umbilicus. The local anaesthetic or opioid injected into the spinal fluid provides anesthesia, analgesia, and motor and sensory blockade. The tip of the spinal needle features a point or small bevel. Recently, pencil-point needles are made available (Whitacre, Sprotte, Gertie Marx, and others).
