Heart Rate Variability Under Propofol and Sevoflurane

Study Overview
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Brief Summary
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Patients were randomized into 2 groups according to the anesthetic, propofol or sevoflurane. Induction and maintenance were standardized, and after the end of surgery, two steady-state recordings were performed at BIS 25 and BIS 55. Bispectral Index and ECG were continuously recorded and cardiac autonomic nervous activity was investigated using spectral analysis of RR Interval variability

Official Title
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Spectral Analysis of Heart Rate Variability at BIS 25 and BIS 55 Under Propofol or Sevoflurane

Conditions
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General Anesthesia

Intervention / Treatment
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* Drug: Sevoflurane
* Drug: Propofol
* Drug: Remifentanil


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA risk classification 1 or 2, scheduled for middle ear surgery, or cardiovascular ANS activity. Exclusion Criteria: preoperative medications that interfere with the autonomic nervous system preoperative medications that interfere with the central nervous system

Ages Eligible for Study
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Minimum Age: 13 Years
Maximum Age: 40 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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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Sevoflurane<br>General anesthesia using sevoflurane as a hypnotic agent, and remifentanil as an analgesic. Two steady state periods of 10 minutes each, one with a steady bispectral index at 25 +/- 5, the other with a steady bispectral index at 55 +/- 5. Continuous recording of heart rate during the last minute of each steady-state. Off-line spectral analysis of heart rate variability. | Drug: Sevoflurane<br>* General anesthesia using sevoflurane as a hypnotic agent<br>Drug: Remifentanil<br>* General anesthesia using remifentanil as an analgesic.<br>|
| Active Comparator: Propofol<br>General anesthesia using propofol as a hypnotic agent, and remifentanil as an analgesic. Two steady state periods of 10 minutes each, one with a steady bispectral index at 25 +/- 5, the other with a steady bispectral index at 55 +/- 5. Continuous recording of heart rate during the last minute of each steady-state. Off-line spectral analysis of heart rate variability. | Drug: Propofol<br>* General anesthesia using propofol as a hypnotic agent<br>Drug: Remifentanil<br>* General anesthesia using remifentanil as an analgesic.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Spectral analysis of heart rate variability with a bispectral index of 25 | Fast Fourier Transform applied to heart rate signal recording | During surgical procedure | 
| Spectral analysis of heart rate variability with a bispectral index of 55 | Fast Fourier Transform applied to heart rate signal recording | During surgical procedure |