Bispectral Index monitoring correlates with sedation scales in brain-injured patients*

Objective:Monitoring critically ill, brain-injured patients with a decreased level of consciousness is challenging. Our goal is to determine in this population the correlation between the Bispectral Index (BIS) and three commonly used sedation agitation scales: the Richmond Agitation-Sedation Scale (RASS), the Sedation-Agitation Scale (SAS) and the Glasgow Coma Scale (GCS) scores. Design:Prospective, single-blinded observational study. Setting:Eight-bed neurology-neurosurgery intensive care unit at the Cleveland Clinic Foundation. Patients:Thirty critically ill patients admitted to the neurointensive care unit with primary brain injury and a decreased level of consciousness. Measurements and Main Results:Patients were prospectively evaluated for level of consciousness using the RASS, SAS, and GCS every hour and simultaneously were monitored continuously with a BIS monitor for 6 hrs. A Spearman’s correlation coefficient was used to correlate the BIS scores with clinical scales. In 15 patients monitored with the newer BIS XP version, the BIS values correlated significantly with the RASS (R2 = .810; p < .0001), SAS (R2 = .725; p < .0001), and GCS (R2 = .655; p < .0001). In 15 patients monitored with the older BIS 2.1.1 software, the correlation was as follows: for RASS, R2 = .30 (p < .008), for SAS: R2 = .376 (p < .001), and for GCS: R2 = .274 (p < .015). This correlation was maintained in patients who received sedative medications. Conclusions:A statistically significant correlation existed between BIS values and the RASS, SAS, and GCS scores in critically ill brain-injured patients, with and without sedation. The newer BIS XP software package may be a useful adjunctive tool in objective assessment of level of consciousness in brain-injured patients.

[1]  Philip D Lumb,et al.  Sedation, analgesia, and neuromuscular blockade of the critically ill adult: revised clinical practice guidelines for 2002. , 2002, Critical care medicine.

[2]  G. Fraser,et al.  Validating the Sedation-Agitation Scale with the Bispectral Index and Visual Analog Scale in adult ICU patients after cardiac surgery , 2001, Intensive Care Medicine.

[3]  Carlayne E. Jackson,et al.  Clinical practice guidelines for the sustained use of sedatives and analgesics in the critically ill adult. , 2002, American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists.

[4]  O. Markand.  Electroencephalography in Diffuse Encephalopathies , 1984, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[5]  Y. Archibald,et al.  The Electroencephalogram in Sepsis‐Associated Encephalopathy , 1992, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[6]  S. Nasraway,et al.  How reliable is the Bispectral Index in critically ill patients? A prospective, comparative, single-blinded observer study* , 2002, Critical care medicine.

[7]  M. M. Hansen,et al.  EFFECT OF STRESS ULCER PROPHYLAXIS ON GASTRIC VOLUME AND BACTERIAL COLONIZATION IN MECHANICALLY VENTILATED, CRITICALLY ILL PATIENTS , 1994 .

[8]  Norbert Roewer,et al.  Is the bispectral index appropriate for monitoring the sedation level of mechanically ventilated surgical ICU patients? , 2002, Intensive Care Medicine.

[9]  H L Paz,et al.  Use of bispectral electroencephalogram monitoring to assess neurologic status in unsedated, critically ill patients , 2001, Critical care medicine.

[10]  G. Fraser,et al.  Assessing sedation during intensive care unit mechanical ventilation with the Bispectral Index and the Sedation-Agitation Scale. , 1999, Critical care medicine.

[11]  P. Coriat,et al.  Detection of brain death onset using the bispectral index in severely comatose patients , 2002, Intensive Care Medicine.

[12]  Jin Liu,et al.  Electroencephalographic Bispectral Index Correlates with Intraoperative Recall and Depth of Propofol-Induced Sedation , 1997, Anesthesia and analgesia.

[13]  R. Polomano,et al.  Beyond the Ramsay scale: need for a validated measure of sedating drug efficacy in the intensive care unit. , 1994, Critical care medicine.

[14]  R. Aneja,et al.  Sedation monitoring of children by the Bispectral Index in the pediatric intensive care unit , 2003, Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies.

[15]  W. Hoffman,et al.  Combining Median Electroencephalography Frequency and Sympathetic Activity in an Index to Evaluate Opioid Detoxification in Patients , 2001, Journal of neurosurgical anesthesiology.

[16]  Theodore Speroff,et al.  Monitoring sedation status over time in ICU patients: reliability and validity of the Richmond Agitation-Sedation Scale (RASS). , 2003, JAMA.

[17]  M. Struys,et al.  Use of continuous bispectral EEG monitoring to assess depth of sedation in ICU patients , 1998, Intensive Care Medicine.

[18]  G. Fraser,et al.  Comparing the Bispectral Index and Suppression Ratio with Burst Suppression of the Electroencephalogram During Pentobarbital Infusions in Adult Intensive Care Patients , 2003, Pharmacotherapy.

[19]  J. Mantz,et al.  Bispectral index variations during tracheal suction in mechanically ventilated critically ill patients: effect of an alfentanil bolus , 2002, Intensive Care Medicine.

[20]  L. Jin,et al.  Electroencephalographic Bispectral Index correlates with intraoperative recall and depth of propofolinduced sedation , 1997 .

[21]  L. Kearse,et al.  Bispectral Analysis of the Electroencephalogram Correlates with Patient Movement to Skin Incision during Propofol/Nitrous Oxide Anesthesia , 1994, Anesthesiology.

[22]  K. Jordan,et al.  Continuous EEG monitoring in the neuroscience intensive care unit and emergency department. , 1999, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[23]  Philip D Lumb,et al.  Clinical practice guidelines for the sustained use of sedatives and analgesics in the critically ill adult. , 2002, Critical care medicine.

[24]  Nassib G. Chamoun,et al.  An introduction to bispectral analysis for the electroencephalogram , 1994, Journal of Clinical Monitoring.

[25]  F. Coluzzi,et al.  BIS monitoring in ICU: advantages of the new XP generation , 2002, Critical Care.

[26]  I. Kissin,et al.  Depth of Anesthesia and Bispectral Index Monitoring , 2000, Anesthesia and analgesia.

[27]  E. Mondello,et al.  BIS and Ramsay score in critically ill patient: what future? , 2002, Minerva anestesiologica.

[28]  J. Berkenbosch,et al.  The Correlation of the Bispectral Index Monitor with Clinical Sedation Scores During Mechanical Ventilation in the Pediatric Intensive Care Unit , 2002, Anesthesia and analgesia.

[29]  L. Caral,et al.  Episodic high irrigation pressure during surgical neuroendoscopy may cause intermittent intracranial circulatory insufficiency. , 2001, Journal of neurosurgical anesthesiology.

[30]  P Manberg,et al.  Bispectral Analysis Measures Sedation and Memory Effects of Propofol, Midazolam, Isoflurane, and Alfentanil in Healthy Volunteers , 1997, Anesthesiology.

[31]  C. Sessler,et al.  The Richmond Agitation-Sedation Scale: validity and reliability in adult intensive care unit patients. , 2002, American journal of respiratory and critical care medicine.

[32]  M. Welte,et al.  Bispectral index-guided sedation with dexmedetomidine in intensive care: A prospective, randomized, double blind, placebo-controlled phase II study* , 2002, Critical care medicine.