A 43-year-old male presented to the emergency department (ED) for evaluation of acute respiratory arrest. Prior to arrival, the patient was at an outpatient surgical center being prepared for a right shoulder arthroscopic surgery under regional anesthesia. The anesthesiologist injected 10 mL of bupivacaine and 30 mL of ropivacaine, of unknown concentrations, while attempting to perform an interscalene block. Soon thereafter, the patient complained of difficulty breathing and subsequently developed complete paralysis and respiratory arrest requiring emergent endotracheal intubation prior to hospital arrival. No additional medications were administered at the time of intubation.\nPhysical exam revealed dilated pupils nonreactive to light, complete flaccid paralysis and inability to withdraw from noxious stimuli. The patient immediately received two liters of 0.9% normal saline and a dopamine infusion, initiated at 5 mcg/kg/min, due to persistent bradycardia (heart rate of 44 bpm) and hypotension. The local poison control center was contacted for recommendations on potential LAT. The decision was made to administer 20% ILE, with a bolus of 125 mL (1.5 mL/kg) over one minute, about 90 minutes after presentation. Shortly after, propofol was initiated for post-intubation sedation at 10 mcg/kg/min. The remaining volume of ILE (125 mL) was then immediately infused over two hours at a rate of 0.013 mL/kg/min.\nApproximately 30 minutes after the initiation of ILE, the patient began to regain brainstem reflexes and eye movement, which progressed to head nods, then movement of his upper extremities. In addition, during that time period, his blood pressure and heart rate improved to within normal parameters. Sixty minutes later, the patient was able to communicate by writing down responses to questions. One hour after that, he had full recovery and was extubated. The patient recovered completely without any evidence of neurological sequelae and was discharged 30 hours after presentation.
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.