Abstract A 26 years old male, weighing 63 Kg, BMI 23.14Kg/ m2 with no known medical comorbidities, underwent laparoscopic cholecystectomy under general endotracheal anesthesia. Intraoperative period was uneventful. At the end of surgery, before reversal and extubation, ultrasound guided bilateral subcostal Transversus Abdominis Plane (TAP) block was performed with 15 ml of 0.2% Ropivacaine on each side for postoperative analgesia.

After 5 minutes of performing the block, patient developed perioral twitching followed by Generalized Tonic-Clonic Seizures (GTCS) lasting for 20 seconds that was treated with Midazolamand Thiopentone extubation was withheld.

Second attempt at extubation 20 minutes later was abandoned due to recurrence of GTCS lasting for 10 seconds and was treated with Thiopentone. Suspecting Local Anesthetic Systemic Toxicity (LAST), Intralipid 20% emulsion was started with 100ml bolus over 1 minute followed by 15ml/ min infusion.Third attempt at extubation after 20 minutes met with the same fate. ABG, Blood sugar and serum electrolytes were normal. A CT brain plain was normal.

Results: After 40 minutes,extubation was successfully attempted the fourth time. Patient was extubated upon full return of consciousness with adequate response to oral commands. Patient was observed in a High Dependency Unit (HDU) for 24 hours before discharge to wards.

Conclusion:The temporal association of seizure occurrence shortly after TAP block in the absence of seizure disorder and cessation of seizures with Intralipid suggests a diagnosis of LAST.