Pain Assessment by Pupil Dilation Reflex (PDR) and Pupillary Pain Index (PPI) in Response to Noxious Stimulation in Anesthetized Adults

University Hospital, Antwerp34 enrolled

Overview

After conduction a pilot study, pupillary dilation reflex (PDR) is measured in response to nociceptive stimulation perioperatively.

An infrared camera of the video pupillometer measures the pupillary dilation reflex (PDR) in response to incremental nociceptive stimuli. The PDR is a robust reflex, even in patients under general anesthesia, and may provide a potential evaluation of the autonomous nociceptive circuit. American Society of Anesthesiologists (ASA) classification I or II patients undergoing elective surgery under general anesthesia are recruited. Enrolled patients perioperative undergo PDR measurement at 2 different standardized times (before and after opioid administration) generated by an inbuilt pupillary pain index (PPI) protocol. PPI, as a surrogate for nociception includes noxious stimulations from 10 up to 60 milli ampere (mA) until pupil dilation is larger than 13% from baseline diameter. Therefore, no inappropriate high stimulation is executed.

Study Type

INTERVENTIONAL

Allocation

Purpose

DIAGNOSTIC

Masking

NONE

Enrollment

Conditions

Nociceptive Pain Monitoring, Intraoperative

Interventions

PDR measurementPROCEDURE

PDR measurement at two standardized times perioperatively: 1. : anesthetized subject by propofol sedation until sedation depth monitor NeuroSense® (NeuroWave Systems Inc, Cleveland, OH) between 40-50 2. : administration of remifentanil via effect site target concentration (Minto-model) at 5 ng/ml, in the absence of adjustments in sedation depth

Eligibility

Sex: ALLMin age: 18 YearsMax age: 75 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Scheduled abdominal or gynecological surgery * ASA I-II Exclusion Criteria: * History of eye deformity, invasive ophthalmologic surgery * Known cranial nerve(s) deficit * Infection of the eye * Predicted difficult airway management (DAF Guidelines) * Chronic opioid use (\>3 months) * Ongoing treatment with beta-blockers, dopamine antagonists, topical atropine * Preoperatively administrated benzodiazepins or antiemetics

Locations (1)

University hospital Antwerp

Edegem, Antwerp, Belgium

Outcomes

Primary Outcomes

Stimulation Intensity

Necessary stimulation intensity to dilate the pupil more than 13%

Time frame: During perioperative period

Secondary Outcomes

Pupillary Pain Index score

Device specific PPI score defined in accordance to stimulation intensity necessary for pupil dilation more than 13%

Time frame: During perioperative period

Systolic blood pressure

Hypertension as a common used parameter for perioperative nociceptive assessment

Time frame: During PDR measurements

Heart rate

Tachycardia as a common used parameter for perioperative nociceptive assessment

Time frame: During PDR measurements

Data from ClinicalTrials.gov

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