title: Linear and nonlinear analysis of heart rate variability during propofol anesthesia for short-duration procedures in children.
abstract: OBJECTIVE
  To determine whether heart rate variability metrics provide an accurate method of monitoring depth of anesthesia, assessing the response to painful stimuli, and assessing neuroautonomic regulation of cardiac activity in children receiving propofol anesthesia for short-duration procedures.
  
  
  METHODS
  Prospective, case series.
  
  
  METHODS
  Sixteen-bed pediatric intensive care unit, oncology unit, and endoscopy suite in a tertiary care children's hospital and ophthalmology examination rooms in an associated eye institute.
  
  
  METHODS
  Thirty-three pediatric patients undergoing propofol anesthesia for short procedures.
  
  
  METHODS
  None.
  
  
  RESULTS
  Heart rate variability metrics studied included mean, SD, low- and high-frequency power, detrended fluctuation analysis (represented by correlation coefficient, alpha), and approximate entropy. Compared with the initial anesthetized state, we found increased heart rate SD (3.17 +/- 1.31 vs. 7.05 +/- 0.26 bpm, p <.0001), heart rate low-frequency power (3.69 +/- 0.36 vs. 4.48 +/- 0.41 bpm(2)/Hz, p <.0001), heart rate low-/high-frequency ratio (1.47 +/- 0.26 vs. 1.26 +/- 0.24, p =.001), and heart rate alpha (1.12 +/- 0.24 vs. 1.35 +/- 0.21, p <.0001) during painful procedure. Mean heart rate (105.8 +/- 13.4 vs. 101.5 +/- 12.4 bpm, p =.005) and heart rate approximate entropy decreased with painful procedure (0.75 +/- 0.19 vs. 0.53 + 0.16, p <.001), whereas there was no significant change in heart rate high-frequency power (3.04 +/- 0.63 vs. 3.16 +/- 0.71 bpm(2)/Hz, p =.26).
  
  
  CONCLUSIONS
  We conclude that power spectral analysis of heart rate variability may be an accurate and clinically useful measure of depth of propofol anesthesia. We speculate that high-frequency heart rate power during propofol anesthesia correlates with depth of anesthesia, whereas low-frequency power allows for assessment of the patient's sympathetic response to pain.
authors.affiliation: Division of Pediatric Critical Care, Department of Pediatrics, Oregon Health Sciences University, Portland, OR, USA.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Toweill
authors.forename: W Daniel
authors.initials: WD
authors.lastname: Kovarik
authors.forename: Richard
authors.initials: R
authors.lastname: Carr
authors.forename: Danny
authors.initials: D
authors.lastname: Kaplan
authors.forename: Susanna
authors.initials: S
authors.lastname: Lai
authors.forename: Susan
authors.initials: S
authors.lastname: Bratton
authors.forename: Brahm
authors.initials: B
authors.lastname: Goldstein
mesh_terms: D000367:Age Factors; D000758:Anesthesia; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D003627:Data Interpretation, Statistical; D004562:Electrocardiography; D019277:Entropy; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D016343:Monitoring, Intraoperative; D015999:Multivariate Analysis; D015742:Propofol / Q000494:pharmacology*; D011446:Prospective Studies; D012119:Respiration; D013514:Surgical Procedures, Operative; D013997:Time Factors
chemical_list: D018686:Anesthetics, Intravenous; D015742:Propofol