AbstractIntroduction: For safe lower abdominal and lower limb surgeries, spinal anesthesia is commonly used. Failure of Spinal Anesthesia can occur even in the expert hands. Causes of failed subarachnoid block includes technical difficulties, poor patient positioning, incorrect insertion of the spinal needle. Resistance to local anesthetic is difficult to diagnose. One of the etiology for Local Anesthetic resistance is history of scorpion bite in the past. Here we report one such case where spinal anesthesia was administered and later upon noticing a failed block, a history of scorpion sting was elicited in operating room and the procedure was carried out under general anesthesia. Case Report: A 55 year old male diagnosed with Open type III B both bone fracture of right leg. Patient gave an alleged history of RTA. With anesthetic plan of Subarachnoid block, 18G IV Cannula was secured. Lumbar puncture was done at L3-L4 Level with 23G Quincke’s Needle in sitting position. 3.5ml (15mg) of Bupivacaine and 60mcg of bupreonorphine was injected. Even after waiting for 20 minutes the patient had no sensory or motor block. There was no fall in blood pressure. During the wait, a further detailed history was taken which revealed that patient had a history of scorpion bite 5 years ago and was treated in a local hospital. Hence the surgery was done under general anesthesia. During the surgery, sudden elevation in blood pressure and ST segment elevation in chest leads was observed. Suspecting intraoperative Myocardial Infarction Inj. Loxicard 20mg and Tab. Ecospirin 150mg was given. ST segment elevations were reverted. ABG which was done to rule out any acid base disorder was within normal limits. After completion of surgery, Reversal (Inj. Neostigmine 3mg + Inj. Glycopyrolate 0.6mg) was given and patient was extubated. Once the patient was stabilised, patient was shifted to ICU for observation. Post operative orders for a chest X-ray, SOB profile, 2D ECHO for intraoperative changes were given and were normal. Conclusion: During routine preanaesthetic evaluation, we never ask about previous exposure to toxins, as in our patient it was discovered later. Now we have made it part of questionnaire in preanesthetic check. The patient was monitored carefully, therefore early detection of ST-segment elevation was possible. The presence of an anesthetic team favored the early diagnosis, so the patient was given a quick and safe intervention.