This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anaesthesia
26 year old female patient wanted epidural for labor analgesia. She was given 12ml of 0.25% bupivacaine immediately after this she developed hypotension, bradycardia, respiratory difficulty. Which of the following explains condition of the patient. 
Select and explain. 
A. Vasovagal attack, B. Systemic toxicity, C. Total spinal anaesthesia, D. Drug allergy
C: Total spinal anaesthesia
Answer: C: Total spinal anaesthesia 
Explanation: Total spinal is one of the dreaded complication of epidural anaesthesia. Accidental puncture of dura, while giving epidural will cause whole volume (10-20ml) of drug to enter subarachnoid space.
This can reach upto cranium producing total spinal block.