Evaluation of the Analgesic Effect of Transcranial Direct Current Stimulation (tDCS) for Sedated Patients in Intensive Care Unit.

Pain management for sedated ICU patients is complex, partly because of the difficulty of assessing pain in non-communicative patients, and partly because of the side effects associated with excessive use of morphine. In this context, the use of another non-pharmacological approach, transcranial direct current stimulation (tDCS), could be of interest. With tDCS, neuronal activity is modulated by inducing a weak electric current through the cerebral cortex between two electrodes applied to the surface of the scalp. Although the mechanisms of action of tDCS are not yet fully understood, the medium-term effects are thought to be linked to the activation of N-methyl-D-aspartate receptors, glutamate-activated receptors involved in cellular memory. The use of tDCS as an analgesic therapy for chronic pain has produced encouraging results in patients suffering from fibromyalgia, migraine and central pain following spinal cord injury, Its use in sedated intensive care patients is unknown. To assess the possible analgesic effect of tDCS in these patients, we will use quantitative pupillometry, a technique already used in routine intensive care, to quantify nociception during a standardized nociceptive simulation.