Background: Estimating pain stimuli in the anesthetized patient can be difficult when based solely upon physiological parameters, especially when vasopressors are used as well. There is an increasing interest during general anesthesia to understand how optimal anesthesia changes by the level of noxious stimulation. Objectively, noxious stimulation measurement monitoring techniques are gaining interest. Although currently, its exact use in routine clinical practice is still not well proven. The aim of this study was to identify relationships between PMD 200 monitoring, Nociception Level (NOL-index) and monitored known physiological signs as well as outcomes during general anesthesia.Method: Eight patients between the ages of 43 and 83 years old and scheduled for major head and neck surgery under general anesthesia were observed in this study. NoL index sensor was placed on one of the patient's fingers before anesthesia was induced, and values were extracted during the intraoperative period.
Results:NoL index values increased intraoperatively during nociceptive stimuli such as jaw lift, endotracheal intubation, catheterization of the bladder, and with surgical skin incision. NoL index increased at several occasions faster, and were more prominent than physiological parameters (BP, HR).
Conclusion:There are identified relationships between PMD 200 monitoring, NOL-index and nociceptive stimulation. NoL index tends to indicate nociceptive responses earlier and more often than hemodynamic outcomes. NoL index can be a physiological marker for optimal analgesic administration and an interesting complement to monitoring equipment intraoperatively worth further studies.