Actigraphic monitoring in critically ill patients: preliminary results toward an "observation-guided sedation".

PURPOSE: The aim of this study is to evaluate continuous wrist actigraphy (measurement of limb movements) in intensive care unit patients as a neurologic status monitoring.
MATERIALS AND METHODS: This is a prospective, observational study on motor activity of adult patients using wrist actigraphs. Nurses recorded the number of sleep and agitation hours as well as assessed pain and anxiety level (verbal numeric rating) and the agitation/sedation level (Richmond Agitation-Sedation Scale).
RESULTS: Thirteen mechanically ventilated patients were studied during their whole intensive care unit stay (total, 165 patients/d). The number of surveyed movements was gathered for each hour, obtaining an estimation of patient motor status. This measure was different between days and nights (33.3 [20.3-49.0] vs 8.5 [4.4-13.8]; P < .001), with a correlation with sleeping hours estimated by nurses (P = .017 during the days [D], P < .001 during the nights [N]), agitation hours (P = .002 D, P = .017 N), Richmond Agitation-Sedation Scale value (P < .001 D and N), pain (P = .012 D), and anxiety (P < .001 D) verbal numeric rating. No differences were found using epochs of 15 or 120 seconds. Compliance with patients and nurses was acceptable.
CONCLUSIONS: Patients' limb movements were significantly related to all studied neurologic status indexes. Continuous actigraphy measuring may become important as a clinical tool both to guide utilization of sedative drugs and to enhance early recognition and management of agitation.