Anaesthetic Management of Left Cerebellopontine Angle Acoustic Nerve Schwannoma in Sitting Position with Intraoperative Electromyographic Facial Nerve Monitoring

Abstract

A case of left cerebellopontine angle acoustic nerve schwannoma in sitting position with electromyographic(EMG) monitoring for facial nerve was managed. The 40 year old male, ASA II, presented with complaints of difficulty in walking, left sided hearing loss, diminution of vision since 3 years and Magnetic Resonance Image (MRI)suggestive of left CPA acoustic nerve schwannoma. Patient was operated under general anaesthesia in sitting position with Mayfield clamp on head without using muscle relaxant as the plan was to use EMG monitoring during tumor resection. Anesthesia was maintained with sevoflurane and propofol and no muscle relaxant was used, yet patient was immobile. Throughout the procedure haemodynamic stability was maintained with noradrenaline injection. Procedure was uneventful with complete excision of tumor and without damaging the facial nerve. Excision of this deep-seated tumor in sitting position without using muscle relaxant is very difficult to manage. This surgery was very challenging from anaesthetic point of view as sitting position itself increases the risk of complications and avoiding movement of patient with Mayfield clamp without using muscle relaxant was a tough job.