The patient agreed to a brachial plexus block via an axillary approach after a detailed discussion of the risks, benefits, and alternatives of regional anesthesia.

After standard American Society of Anesthesiologists-recommended monitors were applied, intravenous midazolam (1 mg) and fentanyl (50 mcg) were administered. The left axilla was identified, and the area around the axillary artery was prepped and draped for the procedure.

After application of an electric nerve stimulator, a 22-gauge, 2-inch B-bevel echogenic needle was inserted superior to the palpated axillary artery. When median nerve activity was identified by wrist flexion at 0.32 mA, 20 mL of 0.5% bupivacaine with 1:200,000 epinephrine was injected with negative aspiration every 5 mL over a period of 90 s. No adverse cardiovascular effects (increase in heart rate by more than 20%) were observed during the injection. At the conclusion of the block, the patient became nonresponsive. Initial small fluttering of her eyelids progressed in 30 s to a generalized tonic-clonic seizure.

Resuscitation measures were initiated with 100% oxygen by bag mask ventilation. Additional intravenous midazolam (2 mg) did not stop the seizure activity, and the patient continued tonic-clonic movements for another 2 min when 50 mg propofol abruptly interrupted the event. The patient was nonresponsive but hemodynamically stable with baseline blood pressure, heart rate, and rhythm for approximately 5 min. At that point, ventricular tachycardia progressed to ventricular fibrillation.

The possible differential diagnoses considered were acute cardiac ischemia, local anesthetic allergic reaction, and local anesthetic systemic toxicity (LAST). Neither acute ischemia nor allergic reaction was seriously considered given the timeline of the event.

Suspicion of LAST led to quick action with immediate attention to airway, breathing, and circulation. In the absence of lipid emulsion, an advanced cardiac life support was initiated.

The patient’s trachea was intubated with a 7.0 endotracheal tube (grade I view), and chest compressions were started. The patient received a total of 3 mg epinephrine, 40 units vasopressin, and 3 rounds of defibrillation. Quality chest compressions were maintained continuously for 10 min. Spontaneous circulation and sinus rhythm returned with intermittent premature ventricular complexes. The patient was hemodynamically stable yet remained unconscious.

In attempts to preserve her neurological function, therapeutic hypothermia was initiated by placing ice bags in the axilla, groin, and neck. Cool fluid was administered through the right internal jugular triple-lumen catheter. These measures quickly achieved core body temperature values of 34.0 °C measured upon arrival to cardiac intensive care unit, 15 min later. The patient remained unconscious without a shivering response. No sedation or neuromuscular blocking agents were given. Four hours after arrest, the patient began to move her extremities and was able to follow commands. The therapeutic hypothermia protocol was discontinued. The patient’s trachea was extubated the next morning on 2 L nasal cannula with oxygen saturation of 99%. The patient was discharged home with full neurologic recovery 4 days after the event with no sequelae. She returned 3 weeks later for wrist surgery under general anesthesia without complications (Fig. 8.1).