<prompt> The most common complication in spinal anaesthesia isPost spinal headacheHypotensionMeningitisArrhythmia  <response>: During surgery 1. Hypotension most common complication Rx. Prophylactic preloading with 1-1.5L of fluids colloid preferred Curative: a Foot end elevation b Infusion of fluids colloids better than crystalloids c Vasopressors Mephentermine Ephedrine Phenyl Ephrine Dopamine if not controlled 2. Bradycardia Rx-Atropine 3. High Spinal complications depends on levels of block up to cardio-accelrator fibres then bradycardia hypotension, if involves cervical Diaphragmatic paralysis occur Rx. IPPV 4. Resp. paralysis Apnea 5. Nausea Vomiting Rx- oxygenation Correct hypotension Metoclopramide Ondansetron if not CI 6. Apprehension anxiety Rx-sedate the patient Post op. 1. urinary retention 2. Neurological complications A. Post spinal headache B. Cauda equina syndrome C. Paraplegia mostly because of epidural haematoma Rs: Exploration drainage of haematoma D. Paralysis of cranial N. 6th most commonly 1st ,9th, 10th are not involved E. Anterior spinal A. syndrome F. Meningitis 3. Backache 