Written By: Friedberg BL, Pericleous A
Date Published: Mon, 2013-02-25
To the editor: With reference to the editorial by Pandit and Cook (1), whilst being the occasional source of PTSD, anaesthesia awareness is not lethal. However, anaesthesia over medication, the natural consequence of failing to monitor depth of anaesthesia, is lethal; specifically to the tune of nearly one American patient every day!(2)
By trending real time, frontalis muscle electromyogram (EMG) as a secondary trace, one can create a relevant device. (3) Responding to spikes in EMG activity as if they were heart rate (HR) or blood pressure (BP) changes is key to making BIS a clinically useful tool. Titrating propofol with BIS without instantaneous EMG is akin to driving one’s car with only the rear view mirror.
Universal BIS/EMG monitoring could reduce anaesthesia drug usage by 30% (4) – a dramatic financial insult to anesthesia drug makers who, in turn, provide millions of various forms of support dollars to organized anesthesia. BIS monitoring is cost effective and remains the best available technology to deal with the twin problems of over- and under- anaesthesia medication. (5)
Disclaimer: Neither I, nor my non-profit Goldilocks Anesthesia Foundation, receive financial support from brain monitor or drug makers.
1. Pandit JJ, Cook TM:National Institute for Clinical Excellence guidance on measuring depth of anaesthesia: limitations of EEG-based technology Br J Anaesth 2013:110:325-328.
2. Li G, et al: Epidemiology of Anesthesia-related Mortality in the United States, 1999-2005. Anesthesiol 2009;110:759.
3. Mathews DM, Clark L, Johansen J, et al. Increases in Electroencephalogram and Electromyogram Variability Are Associated with Increased Incidence of Intraoperative Somatic Response. Anes Analg 2012;114:759-770.
4. Friedberg BL, Sigl JC: Clonidine premedication decreases propofol consumption during bispectral (BIS) index monitored propofol-ketamine technique for office based surgery. Dermatol Surg 2000;26:848-852.
5. Klopman MA, Sebel PS: Cost-effectiveness of bispectral index monitoring. Curr Op Anesthesiol 2011;24:177
Conflict of Interest: None declared