Pupillary Dilation Reflex Assessment for Intraoperative Analgesic Titration.

University Hospital, Antwerp120 enrolled

Overview

In this double blinded randomized controlled study, the pupillary dilation reflex is used for as a nociceptive indicator for opioid administration during elective surgery under general anesthesia.

An infrared camera of the video pupillometer measures the pupillary dilation reflex (PDR) in response of a nociceptive stimulus. This autonomic reflex, parasympathetic mediated in sedated patients, can be generated by various pain stimuli (built in standardized protocol, surgical incision, …) The PDR is a robust reflex, even in patients under general anesthesia, and provides a potential evaluation of the autonomous circuit within the nociceptive evaluation based on pupil dilation upon A-delta and C fibers in both electrical or mechanic stimulation. This double blind randomized controlled trial involving American Society of Anesthesiologists (ASA) classification I-III patients undergoing elective surgery under general anesthesia are recruited. Enrolled patients are randomized in four groups: (1) remifentanil administration depending on PDR results, (2) remifentanil administration depending on decision attending anesthesiologist, (3) sufentanil administration depending on PDR results, (4) sufentanil administration depending on decision attending anesthesiologist.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Enrollment

120

Conditions

Pain, Acute Anesthesia

Interventions

Pupillary dilation reflexDIAGNOSTIC_TEST

Perioperative pupillary dilation reflex assessment is executed every 10 minutes from start sedation until extubation in patients allocated to study arm Intervention 1 and Intervention 3

Standard of careOTHER

Perioperative opioid administration based on the attending anesthesiologist decision (mainly including assessment of heart rate, blood pressure, and limb movement)

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * \> 18 jaar * Elective abdominal or gynaecological operation * ASA (American Society of Anesthesiologists classification): I - II - III Exclusion Criteria: * History of invasive ophthalmological surgery * Known bilateral eye disease * Known optical of oculomotor nerve deficit * Active psychiatrical disease * Proven active pheochromocytoma * Opioid usage \> 7 days preoperative * Ongoing oncological treatment with chemotherapeutic agents * Usage of A-1 adrenergic of beta-blocking agents * Preoperative usage of benzodiazepines * Topical atropine or phenylephrine (eye droplets) * Planned perioperative usage of dopamine antagonists

Locations (1)

University hospital Antwerp

Edegem, Antwerp, Belgium

Outcomes

Primary Outcomes

Postoperative pain

Numeric rating scale (NRS) pain assessment

Time frame: From patient extubation until postoperative day 5

Postoperative analgesia

Analgetic consumption

Time frame: From patient extubation until postoperative day 5

Secondary Outcomes

Stimulation intensity to elicit PDR

Necessary stimulation intensity generated by the pupillometer to elicit a PDR

Time frame: From the day of surgery at the start of general anesthesia, assessed every 10 minutes until the end of surgery or extubation, whichever came first, assessed up to 4 hours

Baseline pupil diameter

Pupil size before stimulation

Time frame: From the day of surgery at the start of general anesthesia, assessed every 10 minutes until the end of surgery or extubation, whichever came first, assessed up to 4 hours

Pupillary dilation reflex amplitude

The amplitude of the pupil enlargement after nociceptive stimulation

Time frame: From the day of surgery at the start of general anesthesia, assessed every 10 minutes until the end of surgery or extubation, whichever came first, assessed up to 4 hours

Pupillary pain index (PPI)

Generated PPI score by the pupillometer in accordance to given stimulation and pupillary dilation reflex amplitude

Time frame: From the day of surgery at the start of general anesthesia, assessed every 10 minutes until the end of surgery or extubation, whichever came first, assessed up to 4 hours

Opioid usage during surgery

Data from ClinicalTrials.gov

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