<Tr> <Th> MeSH </Th> <Td> D000775 </Td> </Tr> <Tr> <Td_colspan="2"> (edit on Wikidata) </Td> </Tr> <P> Spinal anaesthesia (or spinal anesthesia), also called spinal block, subarachnoid block, intradural block and intrathecal block, is a form of regional anaesthesia involving the injection of a local anaesthetic into the subarachnoid space, generally through a fine needle, usually 9 cm (3.5 in) long . For obese patients longer needles are available (12.7 cm / 5 inches). The tip of the spinal needle has a point or small bevel . Recently, pencil point needles have been made available (Whitacre, Sprotte, Gertie Marx and others). </P> <P> Spinal anaesthesia is a commonly used technique, either on its own or in combination with sedation or general anaesthesia . Examples of uses include: </P>

How big is the needle for a spinal block