Evaluation of Pulse Oximeter Derived Perfusion Index as an Objective Tool for the Assessment of Analgesia during Head and Neck Oncosurgery under Anesthesia

either sex, American Society of Anesthesiologists (ASA) grade I and II, aged between 20 and 55 years, scheduled for planned head and neck oncosurgery, were included in the study.It is a prospective, nonrandomized study conducted from January to December 2020.Patients with peripheral vascular disease, autonomic dysfunction, chronic pain disorder, or allergy to drugs used in the study were excluded from the study.On the day of surgery, after taking the patient on the operation table, all routine monitors were attached: an electrocardiogram (ECG), noninvasive blood pressure (NIBP), and pulse oximeter (SpO 2 ).PI was measured by Masimo Radical-7 SET pulse oximeter, and the probe was attached on the index finger contralateral to the side of the blood pressure cuff to get uninterrupted PI monitoring.All data were recorded by faculties of anesthesiology.Preinduction values of PI, HR, and mean arterial pressure (MAP) were noted.