Hypothermia

During cooling for CPB, the total power and peak power frequency of the high-frequency band are highly correlated with temperature using Fourier analysis and spectral edge data; however, there is significant variability between subjects, especially during cooling.^[53] Complete electroencephalographic suppression usually develops at 15°C to 18°C. Levy and colleagues^[43] demonstrated an improved ability to quantify the effects of hypothermia

Figure 38-8 Changes in the compressed spectral array during hypotension. (From Stockard JJ, Bickford RG: The neurophysiology of anesthesia. In Gordon E [ed]: A Basis and Practice of Neuroanesthesia. New York, Elsevier, 1981, p 3.)