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
[{'content': 'Anesthetic agent with vasoconstrictor is contraindicated in? \nSelect and explain. \nA. Finger block, B. Spinal block, C. Epidural block, D. Regional anesthesia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The use of vasoconstrictors (epinephrine or adrenaline) along with a local anesthetic is usually avoided in case of ring block or finger block as it causes severe vasocontriction (direct alpha adrenergic effect). As this vaso-constriction in the end aeries can lead to gangrene formation. Ref: Neural blockade in clinical anesthesia and management of pain, Issue 494 - Page 124, By Michael J. Cousins, Phillip O. Bridenbaugh; Fundamentals of Surgical Practice By Andrew Kingsnoh, Douglas Bowley, Page 147.', 'role': 'assistant'}]