Application Of Heart Rate Variability Parameter From Phase Rectified Signal Averaging Analysis For Assessment Of Automatic Nervous System Activity In Patients Undergoing Gynecological Surgery During General Anesthesia

Objectives:This study monitored the parameters of the hemodynamics, bispectral index (BIS),5-minutes conventional heart rate variability (HRV) analysis and5-minutes phase rectified signal averaging (PRSA) analysis in patients undergoing abdominal supracervical hysterectomy during general anesthesia. Deceleration capacity of heart rate (DC) and acceleration capacity of heart rate (AC) derived from PRSA analysis were investigated at the same time in order to observe the activity of autonomic nervous system (ANS). Especially the sensitive indicators which can identify the abnormal reaction of vagus caused by the traction of gynecological surgery were explored for practicable clinical application of the prevention of serious circulation complications during general anesthesia.Methods:Twenty-five patients scheduled for elective abdominal supracervical hysterectomy under intravenous and inhalational balanced general anesthesia were studied, ASA Ⅰ～Ⅱ. Penehyclidine hydrochloride0.5mg was given30minutes before anesthesia. After entering the operation room, ECG, SpO2, BP were initiated and the BIS monitor was used to monitor the depth of anesthesia. The ECG signal was recorded by personal computer simultaneously during the operation. The whole recorded ECG signal was sectioned into5-minutes segments. Off-line HRV analysis was proceed using MATLAB. Anesthesia was induced with Midazolam0.05mg/kg, Fentanyl3p.g/kg, Etomidate0.3mg/kg, Rocuronium Bromide0.6mg/kg. After laryngeal mask airway insertion, mechanical ventilation was controlled with tidal volume10mg/kg at a rate of14breaths/min. Anesthesia was maintained with a target-controlled infusion of propofol (3μg/ml), sevoflurane (end-tidal1.0MAC) remifentanil (0.05μg/kg-min) and supplemental vecuronium bromide (0.02mg/kg) Atropine0.01mg/kg, Neostigmine0.02mg/kg were given while surgery was finished. After removing the laryngeal mask, patients were admitted to the ward. There were five HRV analysis segments (5min) in this study:before anesthesia (To), anesthesia induction (T1), intraoperative period without traction (T2), intraoperative period with traction (T3), surgery was finished (T4). The quantitative indicators of5-minutes HRV analysis in the time domain, the frequency domain, the nonlinear and the PRSA were calculated.Result:(1) Parameters of hemodynamic and BIS:In contrast to To, HR increased at T1and decreased at T3, MAP increased at T1, BIS decreased in T1, T2, T3. In contrast to T2, BIS increased at T4.(2) HRV analysis parameters:Compared to T0, SDNN,1gTP, SD2increased at T1, but decreased at T2, rMSSD, SD1decreased at T1, T2, T4,1gLF decreased in T1, T2, T4,1gHF decreased in T1, T2, T3, T4, LFn increased at T1, T4,HFn decreased in T1, T4, LF/HF increased in T1, T4, DC and AC decreased at T1, T2, T3, T4In contrast to T2, SDNN,1gTP, SD2increased in T1, T3, T4, rMSSD, SD1increased in T3,1gLF increased in T1, T3, T4,1gHF increased in T1, T3, LFn increased in T4, HFn decreased in T4, LF/HF increased in T4, DC increased in T3, AC increased in T1, T3.|DC|-|AC|were negative at To, T1, T4and positive at T2, T3.(3) Correlations:DC had a high correlation with rMSSD,1gHF, HFn and SD1of HRV indicators, however, the correlation among DC and SDNN,1gTP,1gLF, LFn, SD2was relatively poor. AC had a high correlation with rMSSD,1gHF, HFn and SD1of HRV indicators, however, the correlation among AC and SDNN,1gTP,1gLF, LFn, SD2was relatively poor.Conclusion:The parameters of PRSA analysis had a high correlation with conventional short-term HRV indicators, and could reflect the activity of ANS especially vagus in patients undergoing traction of gynecological surgery during general anesthesia satisfyingly. DC and AC derived from PRSA analysis coincided with the hemodynamic parameters, reflect the abnormal activity of vagus sensitively meanwhile.|DC|-|AC|can be used for evaluate the emergencies of clinic, such as sympathetic stress, vagal reflex and so on. It may play more roles in clinical application for prophylaxis of the serious circulation complications caused by vagal reflex.