View clinical trials related to Knee Surgery.
Filter by: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.