During canal irrigation the patient reports immediate severe pain and rapid facial swelling — a sodium hypochlorite accident. What is the immediate management?

Correct answer: D. Stop irrigating, irrigate the canal with saline, control the pain, apply a cold compress and monitor the patient closely

• A. Sealing and dismissing the patient abandons them during the period when swelling, ecchymosis and possible airway or neurological complications develop.
• B. This is not an allergic reaction. It is chemical tissue necrosis and haemorrhage caused by extrusion of hypochlorite beyond the apex, and an antihistamine does nothing for it.
• C. Extraction is not indicated and adds surgical trauma to already compromised tissue.
• D. CORRECT. Stop the irrigant immediately, flush the canal with copious sterile saline to dilute residual hypochlorite, provide profound analgesia, and apply cold for the first 24 hours to limit swelling and bleeding. Then reassess frequently — this patient needs to be seen the next day and followed until resolution.

Note: Full protocol: saline flush, analgesia (consider a long-acting local anaesthetic), COLD compress for the first 24 h then WARM compresses thereafter, antibiotics if secondary infection is a concern, corticosteroids for significant swelling, daily review, and referral if there is airway involvement or paraesthesia. Expect ecchymosis to appear and worsen for several days. PREVENTION: side-vented needle, placed 2–3 mm short of working length, never wedged, with passive low-pressure delivery.