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Infrared Pupillometry During General Anesthesia to Predict Pain

NCT02058511 · Status: TERMINATED · Phase: NA · Type: INTERVENTIONAL · Enrollment: 24

Last updated 2019-02-15

Study results available
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Summary

The study comprises of a series of pupillary measurements using infrared pupillometry in patients undergoing arthroscopic knee surgery of any type.

Infrared pupillometry will be used to assess whether a painful stimulus results in pupillary reflex dilation (PRD). The extend of the PRD may be an indicator how painful a stimulus is. This may help to predict the amount of discomfort a patient will be experiencing after emergence from general anesthesia.

In addition to measuring the pupillary reflex dilation, we will also measure oscillations of pupil size before and after indiction of anesthesia, as well as during recovery. These spontaneously occuring oscillations in pupil size, also called hippus, appear to be sensitive to anesthetics and opioids. However, the effect of these drugs on hippus has not been systematically addressed.

The aim of the study is

1. to identify whether regional anesthesia techniques such as femoral and sciatic nerve blocks will block the PRD. This would allow assessment of block success in the anesthetized patient.
2. to correlate the extent of the pupillary reflex dilation and hippus in the anesthetized patient during and at the end of surgery with early postoperative pain scores and subsequent analgesia requirements. Such correlation would allow to predict the amount of postoperative pain before the patients emerge from general anesthesia.

Conditions

  • Postoperative Pain
  • Objective Assessment of Sedation

Interventions

DRUG

Anesthesia Premedication, Induction and Maintenance

The enrolled patients receive standard of care general anesthesia for knee arthroscopy. No additional pharmacological interventions are performed in study participants. The administered drugs, as outlined in the arms section, are midazolam, fentanyl, propofol, and sevoflurane. Study patients receive analgesic drugs as needed in the recovery room if they experience pain.

PROCEDURE

Pupillometry after administration of anesthetic drugs

All study patients receive the standard of anesthetic care. Every time a anesthetic drug has been administered, changes in pupillary oscillations will be recorded. Assessment of pupil size and movements by shining infrared light into the eye and measuring the reflection over a 20 s period The administered drugs are: Midazolam 1-2 mg iv, Fentanyl 1mcg/kg body weight, Propofol for anesthesia induction 2-2.5 mg/kg body weight, Sevoflurane as needed for maintenance of general anesthesia.

Sponsors & Collaborators

Study Design

Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Model
SINGLE_GROUP

Eligibility

Min Age
18 Years
Max Age
99 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2012-11-30
Primary Completion
2016-11-30
Completion
2016-11-30

Countries

  • United States

Study Locations

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Entities

Companies

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT02058511 on ClinicalTrials.gov