It's everybody's BIS™

A positive surgical outcome includes much more than remedying the problem requiring surgery.

The patient experience, from initial anesthesia delivery through surgery and then recovery can be negatively impacted when not enough-or too much-anesthesia is used.

Recent, peer-reviewed evidence now suggests that brain function monitor guided anesthetic dosing may decrease the rate of postoperative delirium.

Brain function monitoring with Bispectral Index"' (BIS™) technology during surgical procedures gives you the ability to directly monitor the anesthetic effect on your patient's brain to optimize the anesthetic dosing.

This web page is intended as a resource to help you identify and reduce the risks of postoperative delirium in the elderly and patients at high risk.

Delirium: The Problem and Solution

In the clinical review "Anticipating and managing postoperative delirium and cognitive decline in adults",([FOOTNOTE=Lepouse, C., Lautner, C., et al. Emergence delirium in adults in postanaesthesia care unit. British Journal Anaesthesia. May 2, 2006;(96) 747-53.],[ANCHOR=View Abstract],[LINK=/content/covidien/websites/medtronic/com/en/covidien/support/clinical-evidence.html?id=852773]) the authors conclude:

  • "Neurobehavioral problems are common after surgery" and include "emergence delirium, postoperative delirium, and postoperative cognitive decline".
  • Delirium is defined as having "reduced clarity, inability to focus, disorientation, memory loss, speech problems and other factors".
  • "Postoperative delirium is the most severe form of delirium". In fact, it is "...tantamount to acute brain failure and should be considered akin to other postoperative organ failures".

The clinical team may not recognize more than 50% of delirium cases.([FOOTNOTE=de Lange, E., Verhaak, P.F., van der Meer, K. Prevalence, presentation and prognosis of delirium in older people in the population, at home and in long term care: a review. Int J Geriatr Psychiatry. Feb 28, 2013.],[ANCHOR=View Abstract],[LINK=/content/covidien/websites/medtronic/com/en/covidien/support/clinical-evidence.html?id=852771])

Risk Factors for Postoperative Delirium

Earlier research concluded that "univariate factors associated with delirium include age, preexisting cognitive impairment, greater preoperative functional limitations and a history of prior delirium".([FOOTNOTE=Selinger, S. Preventing Hospital Delirium. The New Old Age blog. New York Times Website. November 11, 2011. Accessed March 6, 2015.],[ANCHOR=View now],[LINK=]) However, in a more recent randomized controlled trial of 1155 patients, it was shown that "episodes of deep anesthesia (bispectral index score <20) were independently predictive for postoperative delirium".([FOOTNOTE=Inouye, Sharon K. et al. Postoperative Delirium in Older Adults: Best Practice Statement from the American Geriatrics Society. Intraoperative Measures to Prevent Delirium. J Am Coll Surg. 2014;220;2 ,136-148.e1.],[ANCHOR=View Abstract

The type of operation and degree of operative stress is also a factor. For example, high-operative stress vascular procedures can carry a high risk of delirium in elderly patients - up to 36%.([FOOTNOTE=Leslie, D.L., Marcantonio, E.R., Zhang, Y., Leo-Summers, L., & Inouye, S.K. (2008). One-year health care costs associated with delirium in the elderly population. Archives of Internal Medicine. 168(1), 27-32.],[ANCHOR=View Abstract],[LINK=/content/covidien/websites/medtronic/com/en/covidien/support/clinical-evidence.html?id=852774])