+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Translate
+ Recently Requested

How reliable is the Bispectral Index in critically ill patients? A prospective, comparative, single-blinded observer study

How reliable is the Bispectral Index in critically ill patients? A prospective, comparative, single-blinded observer study

Critical Care Medicine 30(7): 1483-1487

To establish a correlation between a reliable subjective measure, the Sedation-Agitation Scale (SAS), and an objective tool, the Bispectral Index (BIS), for monitoring critically ill patients with a decreased level of consciousness. Prospective, comparative, single-blinded observer study. Surgical and medical intensive care units of the Tufts-New England Medical Center, a 349-bed tertiary care, academic medical center. A convenience sample of 20 adult, critically ill patients with a decreased level of consciousness. The data from one patient were excluded because the patient did not meet inclusion criteria. Patients were prospectively evaluated by a blinded observer using the SAS to subjectively determine their level of consciousness. Sedation levels varied from unarousable (SAS score of 1), to very sedated (SAS score of 2), to mildly sedated (SAS score of 3). Simultaneously, the patients were continuously monitored for 4-6 hrs with the BIS device. There was wide variability in BIS scores for any given level of consciousness as compared with the SAS. Unarousable patients had BIS scores ranging from 23 to 97, with a median score of 50 and an interquartile range of 24. Very sedated patients had BIS scores ranging from 35 to 98, with a median score of 68 and an interquartile range of 36. Mildly sedated patients had BIS scores ranging from 67 to 91, with a median score of 76 and an interquartile range of 8. Overall, there was a less than satisfactory correlation between BIS values and SAS scores (r =.36, p <.001). However, the correlation improved with subgroup analysis when BIS values associated with excessive muscle movement were excluded (r =.50, p <.001). The correlation between SAS and BIS scores was suboptimal and inconsistent in a heterogeneous group of critically ill patients. The generation of BIS hardware and software, studied herein, is neither reliable nor valid for routinely monitoring the level of consciousness in the critically ill patient. Excessive muscle movement by the patient is an important and spurious influence on BIS values and seriously undermines BIS reliability.

(PDF emailed within 0-6 h: $19.90)

Accession: 046280972

Download citation: RISBibTeXText

PMID: 12130966

DOI: 10.1097/00003246-200207000-00014

Related references

Comparative effects of propofol, landiolol, and nicardipine on hemodynamic and bispectral index responses to endotracheal intubation: a prospective, randomized, double-blinded study. Journal of Clinical Anesthesia 20(4): 257-262, 2008

Monitoring sedation in critically ill patients: bispectral index, Ramsay and observer scales. European Journal of Anaesthesiology 23(8): 649-653, 2006

Blue Diaper Syndrome and PCSK1 Mutations. Pediatrics 141(Suppl 5): S501-S505, 2018

Sensitivity and specificity of bispectral index for classification of overt hepatic encephalopathy: a multicentre, observer blinded, validation study. Gut 57(1): 77-83, 2007

Bispectral-index-guided versus clinically guided remifentanil/propofol analgesia/sedation for interventional radiological procedures: an observer-blinded randomized study. Anesthesia and Analgesia 103(2): 378-84, Table of Contents, 2006

The relationship between the Bispectral Index (BIS) and the Observer Alertness of Sedation Scale (OASS) scores during propofol sedation with and without ketamine: a randomized, double blinded, placebo controlled clinical trial. Journal of Clinical Monitoring and Computing 30(4): 495-501, 2017

How accurate is magnetic resonance angiography in predicting neurovascular compression in patients with trigeminal neuralgia? A prospective, single-blinded comparative study. British Journal of Neurosurgery 17(1): 60-64, 2003

Active treatment programs for patients with chronic low back pain: a prospective, randomized, observer-blinded study. European Spine Journal 4(3): 148-152, 1995

Entropy and bispectral index for assessment of sedation, analgesia and the effects of unpleasant stimuli in critically ill patients: an observational study. Critical Care 12(5): R119, 2008

Electroacupuncture reduces the dose of midazolam monitored by the bispectral index in critically ill patients with mechanical ventilation: an exploratory study. Acupuncture in Medicine 30(2): 78-84, 2012

Comparison of three intensive programs for chronic low back pain patients: a prospective, randomized, observer-blinded study with one-year follow-up. Scandinavian Journal of Rehabilitation Medicine 29(2): 81-89, 1997

Bispectral index monitoring prevent awareness during total intravenous anesthesia: a prospective, randomized, double-blinded, multi-center controlled trial. Chinese Medical Journal 124(22): 3664-3669, 2012

Effects of sling and voluntary constraint during constraint-induced movement therapy for the arm after stroke: a randomized, prospective, single-centre, blinded observer rated study. Clinical Rehabilitation 26(11): 990-998, 2013

Phototherapy using narrowband ultraviolet B and psoralen plus ultraviolet A is beneficial in steroid-dependent antihistamine-refractory chronic urticaria: a randomized, prospective observer-blinded comparative study. British Journal of Dermatology 176(1): 62-70, 2016

The influence of oral VPA on the required dose of propofol for sedation during dental treatment in patients with mental retardation: a prospective observer-blinded cohort study. Epilepsia 53(1): E13-E16, 2012