Pupillary Response to Noxious Stimulation During Isoflurane and Propofol Anesthesia

Larson, Merlín D.; Sessler, Daniel I.; Washington, Denna E.; Merrifield, Benjamin; Hynson, James M.; McGuire, Joseph

doi:10.1213/00000539-199305000-00028

Cited by 109 publications

(67 citation statements)

References 15 publications

(9 reference statements)

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“…We studied only one volatile agent (desflurane) and one -opioid agonist (fentanyl). However, other studies with PRD using the agents isoflurane (12) and propofol (18) have not revealed any differences in the reflex compared with what has been previously observed with the use of desflurane (15,20). Similarly, the depression of PRD has been shown to occur with other -opioid agonists such as remifentanil (3) and alfentanil (14).…”

Section: Discussionmentioning

confidence: 89%

Latency of pupillary reflex dilation during general anesthesia

Larson¹,

Berry²,

May³

et al. 2004

Journal of Applied Physiology

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of pupillary reflex dilation during general anesthesia. J Appl Physiol 97: 725-730, 2004; 10.1152/ japplphysiol.00098.2004.-Areas of insensibility produced by neuraxial anesthesia or peripheral nerve blocks can be detected during general anesthesia by failure of noxious stimulation to trigger pupillary reflex dilation. We examined the latency of pupillary reflex dilation and the effect of fentanyl on the latency of reflex dilation during anesthesia in nine volunteers. We hypothesized that the reflex was generated by slowly conducting C nociceptive fibers and would be significantly delayed if a distal dermatome (L 4) was stimulated compared with a proximal dermatome (C5). We also hypothesized that fentanyl would prolong the latency and alter the shape of the reflex. After induction of general anesthesia, pupillary reflex dilation was measured with an infrared pupillometer every 5 min after stimulations of the L 4 and C5 dermatomes. Fentanyl (3 g/kg) was then given intravenously. Pupillary reflex dilation latencies were calculated by examining each individual measurement. After 3 h, naloxone (400 g) was given intravenously; anesthesia was then discontinued. Pupillary reflex dilation had a long latency and consisted of distinct early and late phases. No differences were found between latencies of reflex dilation after simulation of L 4 and C5 dermatomes either before or after fentanyl administration. Fentanyl at high concentrations essentially eliminated pupillary reflex dilation; but over the 180-min observation period, first early and then late dilation returned. Fentanyl produced a small increase in the latency of the initial early dilation. We conclude that pupillary reflex dilation during anesthesia is not initiated by slowly conducting C fibers and that fentanyl depresses the reflex in a stereotypical manner. nociception; windup; pupil; opioids; sensory block PUPILLARY REFLEX DILATION (PRD) is a midbrain reflex that has been used clinically to define the extent of local anesthetic blockade during general anesthesia. Although the reflex peaks 1 min after the stimulus starts, a more prompt assessment of sensory blockade should be possible by examining the early portion of the reflex. Thus knowledge of the latency of PRD, and the factors that influence latency, is critical for a timely and reliable detection of the reflex, especially when the reflex magnitude has been attenuated by anesthetic adjuvants including opioids (14,19).Studies in anesthetized animals have shown that the reflex latency is ϳ350 ms (2, 23). The feline reflex proceeds from the nociceptor primarily via C-fiber transmission (8) to the spinal cord and then to the midbrain where norepinephrine-containing neurons are activated. These neurons then inhibit the pupilloconstrictor neurons, resulting in a passive dilation of the pupil (11).Although the reflex in anesthetized humans is thought to be similarly expressed (13, 28), preliminary evidence has shown that the latency of PRD in anesthetized humans is remarkably long and proceeds in two distin...

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Section: Discussionmentioning

confidence: 89%

Latency of pupillary reflex dilation during general anesthesia

Larson¹,

Berry²,

May³

et al. 2004

Journal of Applied Physiology

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“…33 Others did not find that esmolol reduced movement to command or pupillary response to noxious stimuli under anesthesia. 34,35 Why the contradictions?…”

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confidence: 99%

“…33 D'autres chercheurs n'ont pu affirmer que l'esmolol réduit le mouvement sur commande ou la réponse pupillaire à des stimuli nociceptifs sous anesthésie. 34,35 Comment expliquer ces contradictions ?…”

unclassified

Are β-blockers anesthestics?

Yang

Fayad

2003

Can J Anesth/J Can Anesth

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“…Larson et al11 demonstrated the superiority of pupillometry for assessing nociception above vital signs during isoflurane and propofol anaesthesia. More recent research from Barvais and colleagues confirms those findings in volunteers during propofol anaesthesia.…”

Section: Discussionmentioning

confidence: 99%

“…Given the development of pupilometers with an integrated automated pupil tracking system,10 PDR can be used during surgical procedures in the operation room for nociceptive state evaluation 11, 12, 13…”

Section: Introductionmentioning

confidence: 99%

Pain assessment by pupil dilation reflex in response to noxious stimulation in anaesthetized adults

Wildemeersch

Peeters

Saldien

et al. 2018

Acta Anaesthesiol Scand

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BackgroundIn response to noxious stimulation, pupillary dilation reflex (PDR) occurs even in anaesthetized patients. The aim of the study was to evaluate the ability of pupillometry with an automated increasing stimulus intensity to monitor intraoperative opioid administration.MethodsThirty‐four patients undergoing elective surgery were enrolled. Induction by propofol anaesthesia was increased progressively until the sedation depth criteria (SeD) were attained. Subsequently, a first dynamic pupil measurement was performed by applying standardized nociceptive stimulation (SNS). A second PDR evaluation was performed when remifentanil reached a target effect‐site concentration. Automated infrared pupillometry was used to determine PDR during nociceptive stimulations generating a unique pupillary pain index (PPI). Vital signs were measured.ResultsAfter opioid administration, anaesthetized patients required a higher stimulation intensity (57.43 mA vs 32.29 mA, P < .0005). Pupil variation in response to the nociceptive stimulations was significantly reduced after opioid administration (8 mm vs 28 mm, P < .0005). The PPI score decreased after analgesic treatment (8 vs 2, P < .0005), corresponding to a 30% decrease. The elicitation of PDR by nociceptive stimulation was performed without changes in vital signs before (HR 76 vs 74/min, P = .09; SBP 123 vs 113 mm Hg, P = .001) and after opioid administration (HR 63 vs 62/min, P = .4; SBP 98.66 vs 93.77 mm Hg, P = .032).ConclusionsDuring propofol anaesthesia, pupillometry with the possibility of low‐intensity standardized noxious stimulation via PPI protocol can be used for PDR assessment in response to remifentanil administration.

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Pupillary Response to Noxious Stimulation During Isoflurane and Propofol Anesthesia

Cited by 109 publications

References 15 publications

Latency of pupillary reflex dilation during general anesthesia

Latency of pupillary reflex dilation during general anesthesia

Are β-blockers anesthestics?

Pain assessment by pupil dilation reflex in response to noxious stimulation in anaesthetized adults

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