Preoperative Measurement of Heart Rate Variability as a Predictor of Postoperative Outcome

Study Overview
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Brief Summary
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The purpose of the study is to confirm the hypothesis that a dysfunction of the autonomic nervous system could complicate the postoperative course in the patient undergoing surgery. Measurement of heart rate variability (HRV) is a non-invasive method for evaluation of the autonomic nervous system.

Detailed Description
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The autonomic nervous system (ANS) plays an important role in the maintenance of systemic homeostasis. The homeostasis is modified continually by internal and external stimuli to which the autonomic nervous system modulates the response of organism by tight control on essential functions such as circulation, respiration, hormonal secretion and thermoregulation. Dysfunction of the autonomic nervous system could complicate the perioperative course in the patient undergoing surgery; therefore it should be considered as another risk factor during preoperative evaluation. Nowadays the evaluation of the autonomic nervous system function like a tool for prediction postoperative outcome is not considered in daily anaesthesiology practice. Measurement of heart rate variability (HRV) is a method for evaluation the autonomic nervous system function. It is a non-invasive method that provides information about the autonomic regulation of organism and thus it identifies patients with the autonomic nervous system dysfunction.

Official Title
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Preoperative Evaluation of Autonomic Nervous System by Heart Rate Variability as a Predictor of Postoperative Outcome in the Patient Undergoing Major Elective Abdominal Surgery

Conditions
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Major Abdominal Surgery

Intervention / Treatment
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* Procedure: Pre-operative measurement of heart rate variability


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 21 years of age and above anticipated duration of surgery more than 120 minutes estimated blood loss exceeding more than 15% of blood volume American Society of Anesthesiology (ASA) classification 2 or 3 Exclusion Criteria: pregnant or lactating women age below 21 years of age emergency surgery American Society of Anesthesiology (ASA) classification 1 sepsis and septic shock severe cardiac arrhythmias

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 90 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

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Pre-operative HRV group<br>Pre-operative measurement of heart rate variability in patients undergoing elective major abdominal surgery. | Procedure: Pre-operative measurement of heart rate variability<br>* Pre-operative measurement of heart rate variability in patients undergoing elective major abdominal surgery<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pre-defined postoperative complications for up to 28 days after surgery | The followed postoperative complications include infectious, respiratory, cardiovascular, abdominal, renal complications, massive postoperative bleeding and preoperative death. | 24 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The length of hospitalization | Length of hospital stay will be obtained from the patient record. | 24 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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heart rate variability, post-operative outcome