Level Of Consciousness
NICE guidance (NICE diagnostics guidance 6, (www.nice.org/dg6) was issued in November 2012 on depth of anesthesia monitors and highlighted the clinical importance of measuring a patient’s response to anesthesia. Individual response to anesthetic agents can lead to: either inadequate levels of anesthesia, in which patients can become aware during surgery – and possibly suffer from post traumatic stress disorder thereafter; or excessively deep anesthesia, causing prolonged recovery time, heart attacks, stroke and post operative cognitive dysfunction.
A number of depth of anesthesia monitors were evaluated in the NICE guidance with the BISTM (Bispectral Index) technology being particularly highlighted. In light of the impact of anesthesia on hemodynamic physiology, BISTM technology (www.covidien.com) has been integrated into the LiDCOrapidv2 monitor enabling clinicians to titrate anesthesia with its hemodynamic effects, thus ensuring that neither over-anesthetising, nor under-anesthetising, nor dramatic falls in blood pressure and flow need take place.
The LiDCOrapidv2 is the first multiparameter hemodynamic monitor specifically designed for use in the highly demanding conditions encountered in the operating theatre.
The LiDCOrapidv2 is available with an optional module (BISTM) for EEG signals, providing the ability to monitor the state of the brain based on acquisition and processing of EEG signals. The BISTM system processes raw EEG signals to produce a single number, called the Bispectral Index, or BIS, which may be used as an aid in monitoring the effects of certain anesthetic agents. Its use may be associated with a reduction in the incidence of awareness with recall in adults during general anaesthesia and sedation.
BISTM is a consciousness monitoring technology proven in rigorous prospective clinical studies to help clinicians reduce the incidence of awareness in adults with recall by approximately 80%.
Prospective, randomized studies have shown reductions in the use of certain primary anesthetic agents when titrated to the BISTM Index. Prospective randomized studies have shown that when anesthetic agents were titrated to the BISTM Index, patients woke up faster, were extubated sooner, and were more oriented on arrival at the post anesthesia care unit, compared to standard methods of practice.
Gan T, Glass P, Windsor A, Payne F, Rosow C, Sebel P, Manberg P. Bispectral index monitoring allows faster emergence and improved recovery from propofol, alfentanil, and nitrous oxide anesthesia. BIS Utility Study Group. (1997) Anesthesiology, 87(4):808-815.
Song D, Joshi G, White P. Titration of volatile anesthestics using bispectral index facilities recovery after ambulatory anesthesia. (1997) Anesthesiology, 87(4):842-848.
Luginbühl M, Wüthrich S, Petersen-Felix S, Zbinden AM, Schnider TW. Different benefit of bispectal index (BIS) in desflurane and propofol anesthesia. Acta Anaesthesiol Scand. 2003;47(2):165-173.
Ekman A, Lindholm M-L, Lennmarken C, Sandin R. Reduction in the incidence of awareness using BIS monitoring. (2004) Acta Anaesthesiol Scand. 48(1):20-26.
Myles P, Leslie K, McNeil J, Forbes A, Chan M. Bispectral index monitoring to prevent awareness during anaesthesia: the B-Aware randomised controlled trial. (2004) Lancet. 363(9423):1757-1763.
Depth of anaesthesia monitors – Bispectral Index (BIS), E-Entropy and Narcotrend-Compact M. Issued: November 2012. NICE diagnostics guidance #6
For more information on BIS products, visit www.covidien.com
BIS and Bispectral Index are trademarks of Covidien LP registered in the U.S. and foreign countries.