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 2 was a previously healthy, 52-year-old male with a spontaneous complete rupture of the left supraspinatus tendon. The patient received an arthroscopic rotator cuff repair, and a single-injection ISB combined with TIVA was selected as the anesthetic strategy. Preprocedural BP was 130/60 mm Hg; HR 66 bpm; SpO2 values 99–100%. After ultrasound- and PNS-guided placement of a left ISB, the brachial nerve block was performed by injecting 1% lidocaine (10 mL) followed by 0.375% ropivacaine (10 mL). There was a negative aspiration test for blood and cerebrospinal fluid prior to injection. Physical examination revealed an effective interscalene block. Adverse cardiac or neurologic symptoms were not recorded. After induction of anesthesia, and intubation, TIVA was maintained with propofol and sufentanil. 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 SBP levels of 100–120 mmHg were interrupted by SBP levels of ≥90 and <100 mmHg for a maximum of 35 min due to the application of controlled hypotension. Administration of antihypertensive and/or vasoconstrictor drugs was not recorded. SpO2 (98–100%) and ETCO2 values (34–37%) were normal throughout the case. The duration of surgery was 56 min. After termination of TIVA, and extubation in the OR, the patient presented with impaired consciousness and aphasia, a left-sided gaze preference, dysphagia, mild-to-moderate right-sided central facial palsy, right-sided hemiplegia, and right-sided positive pyramidal tract signs. Brain imaging four hours post-surgery did not detect any cerebral lesions.