Real-time cardiorespiratory coherence detects antinociception during general anesthesia.
Heart rate variability (HRV) may provide anesthesiologists with a noninvasive tool for monitoring nociception during general anesthesia. A novel real-time cardiorespiratory coherence (CRC) algorithm has been developed to analyze the strength of linear coupling between heart rate (HR) and respiration. CRC values range from 0 (low coherence, strong nociception) to 1 (high coherence, no nociception). The algorithm uses specially designed filters to operate in real-time, minimizing computational complexity and time delay. In the standard HRV high frequency band of 0.15 - 0.4 Hz, the real-time delay is only 5.25 - 3.25 s. We have assessed the algorithm's response to 60 anesthetic bolus events (a large dose of anesthetics given over a short time; strongly antinociceptive) recorded in 47 pediatric patients receiving general anesthesia. Real-time CRC responded strongly to bolus events, changing by an average of 30%. For comparison, three traditional measures of HRV (LF/HF ratio, SDNN, and RMSSD) responded on average by only 3.8%, 14%, and 3.9%, respectively. Finally, two traditional clinical measures of nociception (HR and blood pressure) responded on average by only 3.9% and 0.91%, respectively. CRC may thus be used as a real-time nociception monitor during general anesthesia.
Department of Electrical & Computer Engineering, University of British Columbia, Vancouver, BC, Canada. chrisb@ece.ubc.ca
Chris J
CJ
Brouse
Walter
W
Karlen
Guy A
GA
Dumont
Dorothy
D
Myers
Erin
E
Cooke
Jonathan
J
Stinson
Joanne
J
Lim
J Mark
JM
Ansermino
D000465:Algorithms; D000700:Analgesics / Q000494:pharmacology*; D000768:Anesthesia, General; D002648:Child; D002675:Child, Preschool; D003199:Computer Systems; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D059225:Nociception / Q000187:drug effects*; D012119:Respiration / Q000187:drug effects
D000700:Analgesics