Pupillary dilation reflex and pupillary pain index evaluation during general anaesthesia: a pilot study

Abstract

PDR via automated increased tetanic stimulation may reflect opioid effect under general anaesthesia Further research is required to detect possible confounding factors such as medication interaction and optimization of individualized opioid dosage.

Pupillometry pain index decreases intraoperative sufentanyl administration in cardiac surgery: a prospective randomized study

“…In this context, the manufacturer has developed a PPI that provides an “analgesia score” informing the physician of the status of the nociception/antinociception balance. Wildemeersch et aland Vide et alhave validated the use of the PPI during general anesthesia with remifentanil 14 , 20 . The PPI is able to provide information on pupillary dilatation reflex associated with standardized nociceptive stimulus.…”

“…The pupillometer detects the pupil with an infrared camera, so the measurement is non-invasive and the device never comes into contact with the eye. The AlgiScan PPI mode is programmed to deliver electrical stimulation of increasing intensity from 10 to 60 mA by steps of 10 mA 14 . The pupillary diameter is measured during electrical stimulation.…”

“…When dilation reaches a threshold of 13% change compared to the initial size, the electrical stimulation stops. The intensity of the stimulation that triggered the 13% dilation is used to calculate the PPI score (range from 1 to 9) 14 .…”

“…In this setting, pupillometry appears to be a promising tool to decrease the use of opioids during surgery 13 . However, because PDR assessment can be a subjective process, a novel index [pupillary pain index (PPI)] based on pupillary diameter variation in response to electrical stimuli has been developed 14 . By grading pupillary dilatation with a standardized stimulus, the PPI offers a nociceptive scale.…”

PupilEXT: Flexible Open-Source Platform for High-Resolution Pupillometry in Vision Research

“…When using stimulus spectra along the Planckian locus for triggering the pupil light response, it is essential in measurements that amplitudes in the range of 0.1 to 0.4 mm are captured accurately to specify intrasubject variability (Kobashi et al, 2012) in a pupil model. However, a special requirement for pupil measurements arises when the pupil is used as a biomarker for quantifying the cognitive state (Morad et al, 2000;Merritt et al, 2004;Murphy et al, 2014;Ostrin et al, 2017;Tkacz-Domb and Yeshurun, 2018;Hu et al, 2019;Van Egroo et al, 2019;de Winter et al, 2021;Van der Stoep et al, 2021) or clinical symptoms of diseases (Hreidarsson, 1982;Maclean and Dhillon, 1993;Connelly et al, 2014;Lim et al, 2016;Granholm et al, 2017;Wildemeersch et al, 2018;Chougule et al, 2019). Cognitive processes such as memory load, arousal, circadian status, or sleepiness have a transient impact (Watson and Yellott, 2012) on the pupil diameter with aperture changes of 0.015 to 0.53 mm (Beatty and Wagoner, 1978;Beatty, 1982;Schluroff et al, 1986;Jepma and Nieuwenhuis, 2011;Pedrotti et al, 2014;Bombeke et al, 2016;Tsukahara et al, 2016;Winn et al, 2018), making the reproducibility of such effects difficult if the accuracy of the measurement equipment has not been sufficiently validated.…”