Copyright © 2015 International Anesthesia Research Society. Unauthorized reproduction of this article is prohibited. XXX 2015 • Volume XXX • Number XXX www.anesthesia-analgesia.org 1 Copyright © 2015 International Anesthesia Research Society DOI: 10.1213/ANE.0000000000000609 P rocedure-related pain in the intensive care unit (ICU) is an important concern for caregivers. Although exces- sive use of sedatives and analgesics to control pain may result in oversedation and worsen outcomes, 1,2 inadequate pain therapy may induce hyperalgesia and psychological disorders. 3 Physiological relexes related to pain and noci- ception imply activation of sympathetic nervous system and include increased heart rate (HR), polypnea, and pupil dila- tion. Because pupil diameter and motility depend on the bal- ance between sympathetic and parasympathetic responses, pupillary responses have been studied for their usefulness to detect the presence of pain. 4 The recent development of practical pupil measurement tools has made this approach suitable for clinical practice, and pupillometry has been pro- posed as an alternative method for assessing pain 5 during anesthesia for surgery 6 or out of the operating room. 6–9 Because sympathetic responses are affected by analge- sic drugs, pupil size and variation may relect the extent of analgesia. The goal of the present study was to examine the sensitivity, speciicity, and accuracy of pupillary responses to a calibrated light source to assess the adequacy of anal- gesia before a dressing change in the ICU. Pupillometry was assessed before the dressing change and evaluated as a predictor of pain behavior during the dressing change as measured by the Behavior Pain Scale (BPS). As a second- ary objective, variations in vital signs (i.e., HR and arterial blood pressure [BP]) were compared before and during the nociceptive procedure. METHODS The protocol was approved by the IRB (Société de Réanimation de Langue Française CE-13–35), and the requirement for written informed consent was waived by the IRB. Accordingly, all patients were verbally informed and consented to participate in the study. We prospectively enrolled patients presenting with severe cervical necro- tizing cellulitis, which was associated in some cases with mediastinitis. Study patients required 3 surgical dressing changes per day, each lasting 15 to 30 minutes. The dressing change consisted of debridement of necrotic tissue, clean- ing with antiseptic solutions, and positioning of supericial and deep drainage systems. As we have described previ- ously, 10 patients’ lungs were mechanically ventilated during the procedure, and patients were sedated with a continuous infusion of IV lunitrazepam and fentanyl for analgesia. All patients had a Richmond Agitation Sedation Scale 11 score of −5 before beginning the dressing change. The design of the study started with the measurements of pupil and hemodynamic variables (HR, BP, and noninvasive or arte- rial catheter), followed immediately by the dressing change procedure. The BPS was recorded during the procedure. Pupillometry was assessed using the Neurolight™ (ID MED™, Marseille, France). This device generates a 1-sec- ond 150 Lux lash of light and detects pupillary changes using an infrared camera. Pupillary measurements were performed under sterile drapes just before beginning the dressing change to limit the inluence of surgical light or daylight on the measurements. The opposite eye was closed and protected. The Neurolight device allows automatic measurement of maximal and minimal pupil diameter BACKGROUND: Many patients in the intensive care unit are unable to communicate verbally. Accurately predicting whether such patients will exhibit painful behaviors during noxious pro- cedures and assessing the adequacy of analgesia during those procedures is a challenge. In addition to observational pain assessment tools such as the Behavioral Pain Scale, physiologic indicators such as the pupillary response have been proposed. The pupil is innervated by both divisions of the autonomic nervous system and is affected by pain and analgesic medications. We evaluated the pupillary response to a light stimulus before noxious procedures as a method to predict pain during the procedure. METHODS: We correlated different aspects of the pupillary light relex with established strat- egies for pain assessment to evaluate the adequacy of analgesia before surgical dressing changes performed in the intensive care unit in patients with cellulitis associated with medias- tinitis or not. RESULTS: We found that a percentage of variation in pupil size >19% predicted the presence of pain as assessed by a Behavioral Pain Scale score of >3 with a sensitivity of 100% (95% con- idence interval, 100%–100%) and a speciicity of 77% (95% conidence interval, 54%–100%). CONCLUSIONS: In patients unable to communicate verbally, pupillometry may potentially guide caregivers to adjust analgesia before noxious procedures. (Anesth Analg 2015;XXX:00–00) The Relevance of Pupillometry for Evaluation of Analgesia Before Noxious Procedures in the Intensive Care Unit Anne-Claire Lukaszewicz, MD, PhD, Domitille Dereu, MD, Etienne Gayat, MD, PhD, and Didier Payen, MD, PhD From the Department of Anesthesiology and Critical Care, Lariboisière Hospital, Univ Paris Diderot, Sorbonne Paris Cité, Paris, France. Accepted for publication November 13, 2014. Funding: This work was supported by the “Quadrienal plan for research” from University Paris Diderot and the French Ministry of Research (EA 3509). The authors declare no conlicts of interest. Reprints will not be available from the authors. Address correspondence to Anne-Claire Lukaszewicz, MD, PhD, Depart- ment of Anesthesiology and Critical Care, Lariboisière Hospital, Univ Paris Diderot, Sorbonne Paris Cité, Hôpital Lariboisière, 2 rue Ambroise Paré, 75010 Paris, France. Address e-mail to aclukaszewicz@hotmail.com. BRIEF REPORT E