NCT01685645

Does the Measurement of Pupillary Reactivity by an Automated Pupillometer Determine the Effectiveness of Local Anesthesia Under General Anesthesia?

Does the Measurement of Pupillary Reactivity to Painful Stimulation by an Automated Pupillometer Determine the Effectiveness of Local Anesthesia When Undergoing General Anesthesia?

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 100 (actual)
• Sponsor: Centre Hospitalier Universitaire de Nīmes · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The pupillary pain-meter AlgiScan ® with integrated nociceptive stimulator is a portable, battery-operated device which automatically measures, by means of an infrared camera, pupil diameter. This is measured in response to noxious stimulation produced by a tetanus at a frequency of 100 Hz for 5 seconds. Its intensity varies from 10 to 60 mA. The recording is performed for a period of 13 seconds (3 seconds prior to stimulation, stimulation for 5 seconds, 5 seconds after the stimulation). An interval of 3 minutes is allowed between the two measurements (right and left), which is significantly higher than the time necessary to return to normal (about 20seconds). The pupillary pain index (PPI) ranges from 0 to 10 and is a composite measure of the pupillary diameter reflex to the tetanus stimuli delivered by the AlgiScan device. Smaller scores indicate increased analgesia. The main objective of this study is to determine whether PPI index variation can determine a prognostic threshold of analgesic efficacy of unilateral lower limb sensory nerve block before incision. The measurements are performed after bilateral nociceptive stimulation (blocked side versus non-blocked side) in patients under general anesthesia for major knee surgery.

Detailed description

The secondary objectives of this study are to find a link between the clinical criteria for block failure and the ratio of the blocked side PPI over the unblocked side PPI: * study the potential link between algic thermal sensitivity (tested prior to general anesthesia) and the blocked side PPI (or the asymmetry of the index between the blocked side and the unblocked side). * study the potential link between postoperative morphine consumption and the blocked side PPI index (or the asymmetry of the index between the blocked side and the unblocked side). * study the potential link between consumption of remifentanil during surgery and the blocked side PPI index (or the asymmetry of the index between the blocked side and the unblocked side). * study the potential link between the hemodynamic response to incision and the blocked side PPI index (or the asymmetry of the index between the blocked side and the unblocked side). * study the potential link between morning pain assessment and the blocked side PPI index (or the asymmetry of the index between the blocked side and the unblocked side).

Conditions

• Knee Surgery
• Arthroplasty

Interventions

Type	Name	Description
DEVICE	AlgiScan	The AlgiScan device will be used to monitor analgesia during surgery. The integrated nociceptive stimulator will be used on both legs.

Timeline

• Start date: 2013-07-01
• Primary completion: 2014-06-01
• Completion: 2014-06-01
• First posted: 2012-09-14
• Last updated: 2015-03-26

Locations

1 site across 1 country: France