Effects of Propofol Induction Anaesthesia on the Heart Rate Variability

Study Overview
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Brief Summary
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The ANS plays an important role in the regulation of hemodynamics during anesthesia. Manually blous of propofol during induction anesthesia is reported to reduce both sympathetic and parasympathetic tone; however, it is not clear whether the changes in heart rate variability are associated with propofol concentration.

Detailed Description
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Because the ANS, especially the sympathetic nervous system, plays a major role in regulating cardiovascular homeostasis, knowledge of how anesthetic agents modify sympathetic activity is important for understanding subsequent cardiovascular responses. Spectral analysis of heart rate variability (HRV) is a promising new approach, widely used, noninvasive technique to assess the autonomic indexes of neural cardiac control and has been correlated to the integrity and balance of the sympathetic and parasympathetic activation status. The presence of low-frequency (LF) and high-frequency (HF) oscillatory rhythms in the variability of the R-R interval (RRI) is well established. To date, it is believed that LF is mediated by the parasympathetic and sympathetic systems, whereas HF is mediated primarily by the parasympathetic system. There has been a lot of methodological analysis developed to evaluate the ANS function during anesthesia. In this study, Continuous Wavelet Transform (CWT), believed as a reliable and robust method to access cardiorespiratory dynamics of the ANS due to its adaptability and adjustability between spectral and temporal scale using a window of variable width, was used as a method for analyzing dynamic cardiovascular signals during anesthesia.

Official Title
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Differential Effects of Propofol Induction Anaesthesia on the Heart Rate Variability Dynamics

Conditions
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Autonomic Nervous System Imbalance

Intervention / Treatment
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* Drug: Anesthetics


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The subjects were selected from patients scheduled for surgery under general anesthesia. Exclusion Criteria: recent administration of sedative or opioid drugs, emergency surgery and impairment of renal, hepatic, cardiac or respiratory function.

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Drug: Anesthetics|The ANS plays an important role in the regulation of hemodynamics during anesthesia. Manually blous of propofol during induction anesthesia is reported to reduce both sympathetic and parasympathetic tone; however, it is not clear whether the changes in heart rate variability are associated with propofol concentration. We will observe the relationship of anesthetics and HRV dynamics.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| HRV dynamics | Evaluate the changes in heart rate variability at different propofol concentration | 2 minutes |