Abstract: Objective To evaluate the performance of analgesia nociception index (ANI) measured during general anesthesia with inhalational anesthetics for laparoscopic cholecystectomy. Methods 32 ASAⅠ~Ⅱ patients undergoing laparoscopic cholecystectomy with general anesthesia using sevoflurane were included in this observational study. The depth of anesthesia was maintained from D0 to D2 by Narcotrend (NT) monitoring. The ANI (100 maximum optimal value, 0 minimal value) as well as mean blood pressure (MAP) and heart rate (HR) were observed at 5 different time point: no nociceptive stimuli after induction (T0), laparoscopic pneumoperitoneum (T1), trocar puncture into the abdomen (T2), gallbladder bed dissection (T3), gallbladder removal from abdomen (T4). Results With the same anesthesia depth, ANI decreased significantly (P<0.05) in nociception point T1, T2, T3 and T4, compaired with no stimuli point (T0). The most intense painful stimulation is trocar puncture into the abdomen (T2) of which ANI decreased most rapidly and significantly (40.0±11.4, p<0.001). Conclusions ANI appears to reflect different levels of stimulation during sevoflurane based general anesthesia.

Key words: Analgesia Nociception Index, heart rate variability, general anesthesia