title: Serial changes of pulse wave velocity and correlations with hemodynamic parameters during general anesthesia.
abstract: BACKGROUND
  Increased pulse wave velocity (PWV) is a marker of increased arterial stiffness and is correlated with cardiovascular mortality and mortality of all causes in the elderly and in patients with essential hypertension and type 2 diabetes. There is also a positive correlation between PWV and arterial blood pressure. The changes of PWV in response to general anesthesia and surgical stimulation remain unclear. The aim of this study was to continuously monitor the PWV, blood pressure and heart rate, and to assess their correlations during general anesthesia in women receiving gynecologic surgery.
  
  
  METHODS
  The values of PWV were obtained from calculation of the finger-to-toe distance divided by the transit time using dual-channel photoplethysmography system. The values of PWV, systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate were recorded before anesthesia induction, 5 min before incision, at incision, in continuation for at least 30 min thereafter, and 5 min after discontinuation of sevoflurane. The correlations between PWV and SBP, DBP and heart rate during the general anesthesia were analyzed using Pearson's correlation test.
  
  
  RESULTS
  The serial records of PWV and hemodynamic parameters showed that PWV, SBP, DBP, and heart rate decreased after induction of anesthesia. SBP and DBP increased after surgical incision. There was a trend of progressively declining of PWV and DBP during the general anesthesia but SBP and heart rate remained stationary. All the values of PWV, SBP, DBP, and heart rate increased after discontinuation of anesthesia. There were significant correlations between PWV and SBP (r = 0.4558, P < 0.0001), between PWV and DBP (r = 0.2719, P < 0.0001), between PWV and pulse pressure (r = 0.2067, P < 0.0001), and between PWV and mean arterial pressure (r = 0.3969, P < 0.0001).
  
  
  CONCLUSIONS
  We could evaluate the serial changes of PWV in response to general anesthesia and surgical stimulation using a simple and noninvasive dual-channel photoplethysmography system. The value of PWV, an index of arterial stiffness, has significant correlation with arterial blood pressure.
authors.affiliation: Division of Anesthesiology, Sin Lau Christian Hospital, Tainan, Taiwan, ROC.
authors.forename: Ying-Tzu
authors.initials: YT
authors.lastname: Chen
authors.forename: Chang-Yao
authors.initials: CY
authors.lastname: Chiayg
authors.forename: Ming-Cheng
authors.initials: MC
authors.lastname: Wang
authors.forename: Wei-Chuan
authors.initials: WC
authors.lastname: Tsai
authors.forename: Hsien-Tsai
authors.initials: HT
authors.lastname: Wu
authors.forename: Chi-Chu
authors.initials: CC
authors.lastname: Liu
mesh_terms: D000328:Adult; D000768:Anesthesia, General; D001011:Aorta / Q000502:physiology*; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D017156:Photoplethysmography; D011673:Pulsatile Flow / Q000502:physiology*