<prompt> Structures pierced in lumbar spinal puncture are all of the following except: March 2011Ligamentum flavumDuramaterSupraspinous ligamentPosterior Longitudinal ligament  <response>: Ans. D: Posterior Longitudinal ligament Structures encountered while giving spinal anaesthesia are 1 skin, 2 subcutaneous tissue, 3 supraspinous ligaments, 4 interspinous ligaments, 5 ligamentum flavum, 6 dura and 7 arachnoid Spinal anaesthesia: Site of administration in adults: L4-L5 Site of administration in childrens: L3-L4 Autonomic preganglionic fibres sympathetic are earliest to be blocked Contraindication of spinal anaesthesia: - Severe hypovolumia - Marked coagulopathy - Blood dyscrasia - Raised intracranial pressure Ephedrine is the agent of choice as a vasopressor In high total spinal anaesthesia: Marked hypotension, apnea, dilated pupils and bradycardia is seen 