Changes in the Nociception Level Index During Surgical Resection of Paragangliomas: A Case Report

Nociception is the detection of noxious stimulation by the nervous system. The PMD-200 monitor is a validated, emerging technology for intraoperative monitoring using the nociception level (NOL) index. We describe a pediatric case of an open resection of paraganglionic masses during which episodic increases in NOL index and blood pressure coincided with tumor manipulation, presumably due to a catecholamine surge. Since the patient was under stable and adequate analgesia, the increases in NOL index likely reflected the physiologic effects of tumor handling rather that the presence of a true noxious stimulus. Clinicians should consider this limitation when using this monitor.