Nociception-guided versus Standard Care during Remifentanil–Propofol Anesthesia

Abstract

Abstract Editor’s Perspective What We Already Know about This Topic The nociception level index (Medasense Biometrics Ltd., Ramat Gan, Israel), is a reliable measure of moderate to intense noxious stimulation during anesthesia and surgery What This Article Tells Us That Is New In a randomized trial in patients having major abdominal surgery, compared to standard practice, nociception level-guided analgesia resulted in 30% less intraoperative remifentanil consumption Background The multidimensional index of nociception, the nociception level, outperforms blood pressure and heart rate in detection of nociceptive events during anesthesia. We hypothesized that nociception level–guided analgesia reduces opioid consumption and suboptimal anesthesia events such as low blood pressure and use of vasoactive medication. Methods In this single-blinded randomized study, 80 American Society of Anesthesiologists class I–III adult patients of either sex, scheduled for major abdominal procedures under remifentanil/propofol anesthesia by target-controlled infusion, were included. During the procedure nociception level, noninvasive blood pressure, and heart rate were monitored. Patients were randomized to receive standard clinical care or nociception level–guided analgesia. In the nociception level–guided group, remifentanil concentration was reduced when index values were less than 10 or increased when values were above 25 for at least 1 min, in steps of 0.5 to 1.0 ng/ml. Propofol was titrated to bispectral index values between 45 and 55. The primary outcomes of the study were remifentanil and propofol consumption and inadequate anesthesia events. Results Compared with standard care, remifentanil administration was reduced in nociception level–guided patients from (mean ± SD) 0.119 ± 0.033 to 0.086 ± 0.032 μg · kg -1 · min -1 (mean difference, 0.039 μg · kg -1 · min -1 ; 95% CI, 0.025–0.052 μg · kg -1 · min -1 ; P < 0.001). Among nociception level–guided patients, 2 of 40 (5%) experienced a hypotensive event (mean arterial pressure values less than 55 mm Hg) versus 11 of 40 (28%) patients in the control group (relative risk, 0.271; 95% CI, 0.08–0.77; P = 0.006). In the nociception level–guided group, 16 of 40 (40%) patients received vasoactive medication versus 25 of 40 (63%) patients in the standard care group (relative risk, 0.64; 95% CI, 0.40–0.99; P = 0.044). Conclusions Nociception level-guided analgesia during major abdominal surgery resulted in 30% less remifentanil consumption.