<prompt> An anaesthesia resident was giving spinal anaesthesia when the patient had sudden aphonia and loss of consciousness. What could have happened?Total spinalPartial spinalVaso vagal attackIntra vascular injection  <response>: Development of sudden aphonia and loss of consciousness while giving spinal anaesthesia during injection of spinal anaesthesia suggest the diagnosis of vaso-vagal attack. It often occurs in young, nervours and anxious patients during injection in a sitting position. It is characterized by sudden and transient loss of consciousness.Totalhigh spinal anestheria occurs immediately after injection not during injection. Further total spinal anesthesia has a dramatic course with non-recordable BP, respiratory arrest, longer time required to resolve the symptoms. 