A 30-year-old man undergoes a Bier block for a Colles fracture reduction. After injecting the local anaesthetic into the exsanguinated limb, what is the minimum recommended time before deflating the tourniquet to prevent systemic toxicity?
- A 5 minutes
- B 10 minutes
- C 20 minutes ✓
- D 45 minutes
Correct answer: C. 20 minutes
Explanation
The tourniquet must remain inflated for a minimum of 20 to 30 minutes after local anaesthetic injection. Deflating it earlier allows a sudden bolus of the drug to enter the systemic circulation, risking severe local anaesthetic systemic toxicity, including cardiac arrest.
Reference: Morgan and Mikhail's Clinical Anesthesiology, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.