Trigeminocardiac reflex in neurosurgical practice: Report of two new cases
A 71-year-old male presented with remarkable decrease of vision during the previous 6 months (down to 2/10). The pituitary function tests were compatible with hypo-functioning pituitary gland. The magnetic resonance imaging (MRI) revealed a large pituitary adenoma with remarkable supra-sellar extension []. The basic cardiac evaluations were reported to be in the average normal range. He was on aspirin for long period of time, which was discontinued 10 days prior to operation, and mild antihypertensive Thiazide type medication. It was decided to approach the tumor transsphenoidally. The patient fasted for morning hours prior to surgery. The peroperative antibiotic was given as usual, Cephalexin Lupin Pharmaceuticals, Inc. 2 g IV. Routine monitoring during surgery included electrocardiography (ECG), noninvasive blood pressure (NIBP) end-tidal (ET) concentration of CO2, and pulse oximetry.\nAnesthesia was induced with midazolam (2 mg total dosage), fentanyl (150 μg total dosage) and propofol (2.5 mg/kg), and followed by atracurium (0.5 mg/kg). After intubation, the lungs were ventilated on volume controlled ventilation mode (S/5Aespire Config; Datex-Ohmeda Inc., Madison, WI, USA) with a mixture of medical air and O2 (50-50%). Anesthesia was maintained using isoflurane (1-1.5%). An additional dosage of 50 μg fentanyl was applied every one hour during the intervention. The sella was approached via sub-mucosal transseptal dissection entering the sphenoid sinus by the rhinologist. The soft, pinkish gray tumor evacuated gross totally applying microscopic illumination (KA). Considering leakage of cerebrospinal fluid (CSF) in this stage, it was decided to pack the sella by autologous fat taken from the wall of his abdomen. While packing the sella, his BP dropped to 50/20 mmHg and HR to 38/min. Removing more than two-thirds of the implanted fat, the BP raised to 95/65 mmHg and HR to 88/min. It was preferred to apply surgical absorbable hemostat, Ethicon Inc., and cover it with mucosal flap. Since the bradycardia and hypotension were normalized gradually no excess medications were administered. The postoperative course was uneventful except for CSF leakage, which could be managed with repeated lumbar punctures.