The Pupillary Light Reflex Effects of Anesthetics and Hyperthermia

Belani, Kumar G.; Sessler, Daniel I.; Larson, Merlín D.; Lopez, Michael A.; Washington, Denna E.; Ozaki, Makoto; McGuire, Joseph; Merrifield, Benjamin; Schroeder, Mark E.

doi:10.1097/00000542-199307000-00006

Cited by 38 publications

(11 citation statements)

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“…In order to avoid potential interactions with ambient light, the pupillometer includes a silicone membrane surrounding the orbit, and the lighting in the room was controlled during the procedure in order to avoid light shining directly into the patient’s eyes. Some specific drugs may alter PDR measurement [24-27,32,33]. Droperidol and metoclopramide contract the pupil and reduce the PDR induced by the noxious stimulation.…”

Section: Discussionmentioning

confidence: 99%

Pupillary reflex measurement predicts insufficient analgesia before endotracheal suctioning in critically ill patients

et al. 2013

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IntroductionThis study aimed to evaluate the pupillary dilatation reflex (PDR) during a tetanic stimulation to predict insufficient analgesia before nociceptive stimulation in the intensive care unit (ICU).MethodsIn this prospective non-interventional study in a surgical ICU of a university hospital, PDR was assessed during tetanic stimulation (of 10, 20 or 40 mA) immediately before 40 endotracheal suctionings in 34 deeply sedated patients. An insufficient analgesia during endotracheal suction was defined by an increase of ≥1 point on the Behavioral Pain Scale (BPS).ResultsA total of 27 (68%) patients had insufficient analgesia. PDR with 10 mA, 20 mA and 40 mA stimulation was higher in patients with insufficient analgesia (P <0.01). The threshold values of the pupil diameter variation during a 10, 20 and 40 mA tetanic stimulation to predict insufficient analgesia during an endotracheal suctioning were 1, 5 and 13% respectively. The areas (95% confidence interval) under the receiver operating curve were 0.70 (0.54 to 0.85), 0.78 (0.61 to 0.91) and 0.85 (0.721 to 0.954) with 10, 20 and 40 mA tetanic stimulations respectively. A sensitivity analysis using the Richmond Agitation Sedation Scale (RASS) confirmed the results. The 40 mA stimulation was poorly tolerated.ConclusionsIn deeply sedated mechanically ventilated patients, a pupil diameter variation ≥5% during a 20 mA tetanic stimulation was highly predictable of insufficient analgesia during endotracheal suction. A 40 mA tetanic stimulation is painful and should not be used.

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Section: Discussionmentioning

confidence: 99%

Pupillary reflex measurement predicts insufficient analgesia before endotracheal suctioning in critically ill patients

et al. 2013

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“…[42][43][44] Pupilometry has been extensively validated. 40,41,56,57 In this study we utilized dark-adapted resting pupil diameter, rather than dynamic pupil measurements, as used previously. 42 Our pupilometry data thus demonstrate that rapid absorption of nasal methadone results in a rapid onset of action (10 minutes, with a maximum effect at about 30 minutes), only slightly slower than for intravenous administration but much faster than for oral administration (2 hours).…”

Section: Discussionmentioning

confidence: 99%

Disposition of nasal, intravenous, and oral methadone in healthy volunteers

Dale

Hoffer

Sheffels

et al. 2002

Clin Pharma and Therapeutics

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“…Patients that are kept relatively warm require no active thermoregulation at this stage. ff not kept warm, thermoregulatory vasoconstriction decreases cutaneous heat loss [23], and sequesters metabolic heat to the core [2]. Patient characteristics such as age, size, and associated medical conditions augment both the degree of hypothermia and the resultant effects.…”

Section: Discussionmentioning

confidence: 99%

Hypothermia induced by laparoscopic insufflation

et al. 1995

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Hypothermia is a common postsurgical problem, yet information documenting the impact of laparoscopy on perioperative heat balance is scarce. This paper quantifies the changes in core temperature over a 3-h period of high-flow CO2 insufflation in a randomized, controlled trial of six pigs. Each animal was anesthetized and studied on three occasions under standardized conditions, acting as its own control via insufflation with no gas compared with insufflation by cold gas and warmed gas. Insufflation of CO2 gas at high-flow rates over a prolonged period of time results in a significant fall in core temperature. The provision of warmed rather than cold insufflated gas confers no protection against changes in core temperature during laparoscopic surgery due to the small amount of heat required to warm the gas to body temperature. A much greater effect is the latent heat required to saturate the insufflated gas. Most of the hypothermic effect is due to this, and could be minimized by humidifying the flow.

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The Pupillary Light Reflex Effects of Anesthetics and Hyperthermia

Cited by 38 publications

References 0 publications

Pupillary reflex measurement predicts insufficient analgesia before endotracheal suctioning in critically ill patients

Pupillary reflex measurement predicts insufficient analgesia before endotracheal suctioning in critically ill patients

Disposition of nasal, intravenous, and oral methadone in healthy volunteers

Hypothermia induced by laparoscopic insufflation

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