Abstract
When surgery is performed in the brainstem region, the parasympathetic cardiac reflex via the vagus nerve may occur, possibly resulting in bradycardia/asystole and hypotension. We report a case in which temporary cardiac pacing was useful to prevent recurrent atropine-resistant bradycardia during surgery in the brainstem region. A 42-year-old woman underwent resection of a large ependymoma that extended from the midbrain to the medulla oblongata. She had no episodes of syncope, preoperative bradycardia, or arrhythmia. Because the anticipated long duration of surgical manipulation in the brainstem region came with a high risk of bradycardia/asystole occurrence due to tumor removal, a transvenous pacing (TVP) wire was temporarily implanted before surgery. Just after the beginning of tumor removal, severe bradycardia (28 bpm) and hypotension occurred. Tumor removal was paused, and 0.5mg of atropine was administered intravenously. The heart rate immediately increased to 57 bpm and hemodynamics were stable for 2 min ; however, severe bradycardia (13 bpm) and hypotension recurred 1 min after the resumption of tumor removal. TVP (back-up VVI pacing at 40 bpm) was initiated, and bradycardia and hypotension did not occur again. The subsequent course was uneventful and there were no neurological abnormalities. These findings suggested that atropine was only initially effective in this patient after surgical manipulation was started, and that placement of a TVP wire is useful even when atropine-resistant bradycardia occurs during brainstem surgery.
