RESEARCH Open Access Evaluation of the depth o d

Full list of author information is available at the end of the articleBackground Large numbers of patients admitted to the intensive care unit (ICU) are sedated when mechanically ventilated [1]. Evaluating the depth of sedation is a crucial element in the management of these patients. Indeed, when sed-ation is too deep, it can lead to hemodynamic instability, and when too light, it can cause ventilatory difficulties, accidental extubation, or memorization phenomena. Assessing depth of sedation may be difficult in some situations. For example, in patients with acute respira-tory distress syndrome (ARDS), ventilation often is diffi-cult and may require myorelaxant drugs, which make it impossible to evaluate clinically the depth of sedation. In these cases, current practice suggests shortly interrupting the administration of these drugs on a daily basis to evaluate correctly the sedation level of the patient