Infrared Pupillometry During General Anesthesia to Predict Pain

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.

Timeline

Start

2012-11

Primary completion

2016-11

Completion

2016-11

Outcome

Outcome not reported

Stopped: “Preliminary results showed no ability to predict pain by measuring hippus with pupillometry”

Drugs

Indications

No indication recorded.