title: An evaluation of the validity and potential utility of facial electromyelogram Responsiveness Index for sedation monitoring in critically ill patients.
abstract: OBJECTIVE
  The purpose of this study is to explore the validity of a novel sedation monitoring technology based on facial electromyelography (EMG) in sedated critically ill patients.
  
  
  METHODS
  The Responsiveness Index (RI) integrates the preceding 60 minutes of facial EMG data. An existing data set was used to derive traffic light cut-offs for low (red), intermediate (amber), and higher (green) states of patient arousal. The validity of these was prospectively evaluated in 30 sedated critically ill patients against hourly Richmond Agitation Sedation Scale (RASS) assessments with concealment of RI data from clinical staff.
  
  
  RESULTS
  With derivation data, an RI less than or equal to 35 had best discrimination for a Ramsay score of 5/6 (sensitivity, 90%; specificity, 79%). For traffic lights, we chose RI less than or equal to 20 as red, 20 to 40 as amber, and more than 40 as green. In the prospective study, RI values were red/amber for 76% of RASS -5/-4 assessments, but RI varied dynamically over time in many patients, and discordance with RASS may have resulted from the use of 1 hour of data for RI calculations. We also noted that red/amber values resulted from sleep, encephalopathy, and low levels of stimulation.
  
  
  CONCLUSIONS
  Responsiveness Index is not directly comparable with clinical sedation scores but is a potential continuous alert to possible deep sedation in critically ill patients.
authors: Centre for Inflammation Research, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland. Electronic address: twalsh@staffmail.ed.ac.uk.
authors: Timothy S
authors: TS
authors: Walsh
authors: Centre for Inflammation Research, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland.
authors: Kirsty
authors: K
authors: Everingham
authors: Centre for Inflammation Research, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, Scotland.
authors: Fiona
authors: F
authors: Frame
authors: GE Healthcare Finland Oy, Kuortaneenkatu 2, Helsinki, Finland FI-00510.
authors: T Petteri
authors: TP
authors: Lapinlampi
authors: GE Healthcare Finland Oy, Kuortaneenkatu 2, Helsinki, Finland FI-00510.
authors: Mika O K
authors: MO
authors: Särkelä
authors: GE Healthcare Finland Oy, Kuortaneenkatu 2, Helsinki, Finland FI-00510.
authors: Kimmo
authors: K
authors: Uutela
authors: GE Healthcare Finland Oy, Kuortaneenkatu 2, Helsinki, Finland FI-00510.
authors: Hanna E
authors: HE
authors: Viertiö-Oja
mesh_terms: D000465:Algorithms; D001143:Arousal; D003116:Color; D016292:Procedural Sedation; D016638:Critical Illness; D054810:Deep Sedation; D004576:Electromyography / Q000379:methods*; D005152:Facial Muscles / Q000502:physiology*; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage; D008027:Light; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011595:Psychomotor Agitation / Q000175:diagnosis; D012372:ROC Curve; D012015:Reference Standards; D015203:Reproducibility of Results; D018401:Sample Size; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D006993:Hypnotics and Sedatives
keywords: Critical care; Monitoring; Sedation