Assessment of the relationship between analgesia nociception index (ANI) and some depth of anesthesia indexs (BIS, PRST) and visual analogue pain score (VAS) after open abdominal surgery

Abstract

Abstract Introduction: The analgesia/nociception index (ANI), a 0 –100 non-invasive index calculated from heart rate variability, reflects the analgesia/nociception balance during general anesthesia. This study aimed to evaluate the relationship between ANI with Bispectral Index (BIS), PRST score, and VAS in adult patients undergoing general anesthesia. Patients and Methods: A total of 60 patients of American Society Anesthesiologist(ASA) physical status I and II undergoing open abdominal surgery. All patients were monitored and anesthetized according to the protocol. Measurement and recording ANI, BIS, PRST, VAS at the time of the study. Results: There was a relationship between ANI with PRST, BIS intraoperatively and VAS at recovery period after open abdominal surgery. There was a moderate correlation between ANI and PRST with r = 0.433 (r2 = 0.187, ANI = -3,26*PRST + 56,68) and a low correlation between ANI and BIS with r = 0.362 (r2 = 0.131, ANI = 0.339*BIS + 33.636). And, there was significant negative correlation between the ANI and the VAS score with r = - 0.517 (r2= 0.268, ANI = -4,065*VAS+76.49) postoperatively. Conclusion: The use of ANI monitoring with clinical assessment allows anesthesiologists precise analgesia/nociception balance and the right dosage of analgesics, especially in patients with higher operative risk. Keywords: Analgesia/nociception index; Bispectral index; PRST score; assessment; pain;intraoperative; postoperative.