A 56-year-old woman underwent an uncomplicated left shoulder bone spur removal under general anesthesia with 2 mg of versed, 100 mcg of fentanyl, 150 mg of propofol, and sevoflurane in an outpatient surgery center. After completion of the procedure, the anesthesiologist performed an interscalene nerve block for post-operative pain control utilizing 30 mL of bupivacaine (0.25%). Approximately 5 min after completion of the block, the patient developed bilateral mydriasis, paralysis of all extremities, and respiratory arrest. The patient was immediately intubated, administered IV fluids, ephedrine 15 mg IV, and transferred to an emergency department (ED).\nOn ED arrival the patient was being ventilated through an oral endotracheal tube and was completely paralyzed. Her vital signs were: blood pressure (BP) 108/56 mmHg; pulse 86 per minute; respiratory rate 24 breaths per minute on a ventilator. Her pupils were 6 mm and unresponsive to light bilaterally. She had no response to painful stimulation and had no spontaneous respirations on a ventilator. Her initial blood tests included a complete blood count, electrolytes, liver function tests, cardiac enzymes, and coagulation tests. The lab results were all unremarkable except for a phosphorus of 1.7 mg/dL and lactate of 4 mmol/L. In the ED she was administered a 1-L normal saline bolus and 20% intravenous lipid emulsion 85 mg. Over the next 4 h, the patient progressively regained motor and sensory functions followed by successful extubation in the ED. She was admitted to the hospital for observation and discharged home the next day without any neurologic sequelae.
Patient 1 was a 52-year-old male with a medical history of multiple sclerosis, who underwent arthroscopic rotator cuff repair due to a spontaneous complete rupture of the left supraspinatus tendon. The positioning of the patient applied during surgery was the beach chair position. Preoperative blood pressure (BP) was 135/80 mm Hg; heart rate (HR) 66 beats per minute (bpm); oxygen saturation (SpO2) values between 98% and 100%. For premedication, the patient received orally administered midazolam. Single-injection ISB was performed prior to induction of anesthesia and intubation. Total intravenous anesthesia (TIVA) was maintained with propofol and sufentanil. For left ISB, the patient initially received single-dose injections of 1% lidocaine (20 mL) and 0.75% ropivacaine (20 mL) followed by a second single-dose injection of 0.75% ropivacaine (10 mL) three hours after initial local anesthetic injections and 15 min prior to termination of TIVA, and extubation. Safety checks prior to injection did not show any aspiration of blood or cerebrospinal fluid. Adverse cardiac or neurologic symptoms were not recorded. Advancement and placement of the catheter was performed in PNS technique using a stimulating catheter. An effective ISB was confirmed by physical examination prior to surgery. BP was measured every 5 min with a noninvasive cuff. The patient underwent an uneventful operative rotator cuff repair under the ISB and intravenous anesthesia. Intraoperatively, recorded systolic blood pressure (SBP) levels of 100–110 mmHg were interrupted by SBP levels of ≥90 and <100 mmHg for a maximum of 90 min due to the application of controlled hypotension. Administration of antihypertensive and/or vasoconstrictor drugs was not recorded. SpO2 (98% to 100%), and end-tidal CO2 (ETCO2) values (30% to 34%) were normal throughout the case. The duration of surgery was 170 min. After termination of TIVA, and extubation in the operating room (OR), the patient remained in a severely impaired conscious state. In the postanesthesia care unit the patient showed a sustained severe impairment of consciousness, and neurological examination by a neurologist additionally revealed aphasia, multi-modal neglect to the right, left-sided gaze preference, dysphagia, severe right-sided central facial palsy, severe right-sided hemiparesis graded as 2/5 according to the Medical Research Council (MRC) scale for muscle strength, right-sided positive pyramidal tract signs, and right-sided hemihypesthesia. These symptoms were further accompanied by complex behavioural manifestations (anxiety, vocalization, aggression) and facial motor movements suggesting complex focal seizures. Due to vomiting with pulmonary aspiration, the patient underwent an emergency intubation. Brain imaging four hours post-surgery did not detect any cerebral lesions.