Interscalene Block-Potential for Cardiac Arrest

A 52 year Hypertensive female with normal examination and routine investigations including ECG for upper end humerus surgery was given PNS guided interscalene block supplemented with superficial cervical plexus block. After 20 min, due to inadequate block action, routine general anaesthesia was supplemented. At 25 min post induction of GA, just when surgery was to be started, there was sudden unresponsive hypotension with bradycardia culminating in asystole. CPCR started according to ACLS led to ill sustained ROSC followed by pulse less Ventricular tachycardia twice which reverted with prompt defibrillation. We achieved ROSC with sinus tachycardia, RBBB and ST elevation in lateral leads. Inj nikoran dil and enoxaparin were started empirically for ischemic event. After 1 hr of the event ECG done at ICU admission showed normal sinus rhythm with no ischemic changes. Serum electrolytes, ABG, 2D Echocardiography revealed no abnormality. She was extubated fully awake with no neuro deficits. Coronary angiography showed minor block amenable to medical management. She took discharge after 2 days and was subsequently lost to follow up.