Pleth Variability Index in Modified Prone Position or Knee-chest Position (Concord Position)

Study Overview
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Brief Summary
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To investigate whether PVI predicts the fluid responsiveness in modified prone position undergoing posterior approach cervical operation. Furthermore, modified prone position could influence on dynamic variables including stroke volume variation(SVV), pulse pressure variation(PPV) and PVI.

Detailed Description
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Objective : To compare measurements of pleth variability index (PVI), pulse pressure variation (PPV) and stroke volume variation (SVV) to predict fluid responsiveness in modified prone position or knee-chest position (concord position) for cervical operation. To identify Influence of the modified prone position (concord position) on these variables. Method To assess influence of the position change on PVI and other variables(PPV, SVV) To assess PVI to predict fluid responsiveness at modified prone position

Official Title
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Pleth Variability Index as Predictors of Fluid Responsiveness in Modified Prone Position(Concord Position) or Knee-chest Position

Conditions
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Fluid Responsiveness, Modified Prone Position

Intervention / Treatment
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* Other: volume expansion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anaesthesiologists'(ASA) physical status 1-3 patients who received cervical operation in modified prone position or knee-chest position Exclusion Criteria: Valvular heart disease Congestive heart failure, reduced left ventricular function ( Ejection fraction < 40%) Moderate grade of pulmonary disease Arrhythmia (atrial fibrillation, atrial flutter.. etc.) body mass index > 30 or < 15 kg/m2

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 79 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 |
| --- |
|Other: volume expansion|To assess fluid responsiveness|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To assess influence of the position change on PVI and other variables(PPV, SVV) | When position change from supine to modified prone position, to assess the change of PVI and other variables. The correlation of PVI and cardiac output during this change. | 1.supine position : 5 minute after anesthesia induction with arterial-line insertion 2. 5 min after crystalloid 4 ml/kg loading / 3. modified prone position (baseline) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To measure dynamic variables (pulse pressure variation, stroke volume variation and pleth variability index) in modified prone position | Record the data of variables after 5 minute hemodynamic stability without changes of drugs | 1. Supine position : 5 minute after anesthesia induction with arterial-line insertion 2. 5 minute after a position change to prone 3. before and after fluid loading | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pleth variability index