A0017 Opioid-Free Anesthesia with Neuromonitoring in Acoustic Neuroma Surgery: Case Report

Background: Perioperative opioid administration is associated with adverse effects, particularly in neuroanesthesia. The opioid-free anesthesia (OFA) with propofol, ketamine, and scalp blockade helps to prevent those side-effects and eases neuromonitoring during the intervention.

Case Description: A 59-year-old woman presented with a history of unilateral hearing loss, muscle cramps in the neck, and balance disturbances over the past few months. The magnetic resonance imaging (MRI) revealed a right cerebellopontine-angle lesion compatible with an acoustic neuroma. The patient was scheduled to undergo elective surgery (retromastoid suboccipital craniectomy and excision of the tumor) general anesthesia. Standard monitors included were electrocardiogram (ECG), noninvasive and continuous blood pressure, pulse oximeter, capnograph, brain function monitor (Sedline), and electrophysiological monitoring (somatosensory evoked potentials, motor evoked potentials, electromyography); and use of intraoperative neuromuscular blockade (NMB) was avoided.

General anesthesia was induced in the standard way, a scalp block was performed, and it was maintained with a continuous infusion of propofol and ketamine throughout the procedure, which lasted approximately 12 hours. During the procedure, some disturbances in the electrophysiological recording of the right facial nerve were reported. After the intervention, she was admitted to the PICU and had good control of the pain during the postoperative period, with a visual analog scale (VAS) score of 2, requiring just 2 mg of morphine. The patient was discharged to the ward the next day.

Conclusions: The use of OFA during neurosurgery offers significant advantages, including improvement of hemodynamic stability, adequate hypnotic state, and maintenance of a stable plane of anesthesia. In this case, OFA with propofol and ketamine combined with scalp block provided good pain relief without altering the electrophysiological recording.