An anaesthesia resident was giving spinal anaesthesia when the patient had sudden aphonia and loss of consciousness. What could have happened?

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. Total/high 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.