Evaluation of the analgesia nociception index (ANI) in healthy awake volunteers

摘要

Background Analgesia might be evaluated with simple changes in vital signs, a non-specific and non-sensitive method. Heart rate variability (HRV) correlates with autonomous nervous system activity and can be used to evaluate painful stimuli. Heart rate variability is then transformed into a numeric scale called the analgesia nociception index (ANI), where higher values represent predominant parasympathetic tone, thus low nociception. Under general anesthesia, the ANI decreases following painful stimuli and increases after administration of analgesia, but significant interindividual variability is present. The goal of the present study was to evaluate the ANI as a pain index in healthy awake volunteers.