Correlation Between External Jugular Venous and Superior Vena Cava Central Venous Blood Oxygen Saturation in Patient Under General Anesthesia

Study Overview
=================
Brief Summary
-----------------
After installation of central venous catheter in patients under general anesthesia, paired sample of superior vena cava central venous blood and right external jugular venous blood will be collected and send to central laboratory for venous blood gas analysis. Correlation between superior vena cava central venous blood and right external jugular venous blood oxygen saturation will be determined as primary outcome.

Detailed Description
-----------------
All patients age between 18-65 year old who undergoing surgery under general anesthesia and superior vena cava central venous catheter installation anticipated are eligible. The tips of superior vena cava central venous catheter was confirmed by Chest x-ray. Next 1 hour after skin incision, 1 ml of venous blood sample is taken from superior vena cava central venous catheter of right external jugular vein then send to central laboratory for venous blood gas analysis. The demographic data will be recorded. Correlation between superior vena cava central venous blood and right external jugular venous blood oxygen saturation will be determined the primary outcome and partial pressure of carbon dioxide will be determined as a secondary outcome.

Official Title
-----------------
Correlation Between External Jugular Venous and Superior Vena Cava Central Venous Blood Oxygen Saturation in Patient Under General Anesthesia

Conditions
-----------------
Central Venous Oxygen Saturation

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Written consent obtained from patient or next of kin a day before operation date Patient age between 18-65 years old undergoing syrgery under general anesthesia Superior vena cava central venous catheter anticipated for CVP mesurement, innotropic or vasopressor administration,pulmonary artery catheter insertion route Anticipated right external jugular venous sampling time less than 5 minutes The site of blood sample collection easily access during operation Exclusion Criteria: No jugular central venous catheter installation or other route selected Duration of paired sample collection more than 10 minutes Can not collected blood sample from right external jugular vein within 3 attemps The site of blood sample collection difficulty access during operation Pateint or next of kin refuse to participate

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------
What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of venous oxygen saturation | Correlation of venous oxygen saturation between external jugular vein and superior vena cava | 1 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of venous partial pressure of carbon dioxide | Correlation of venous partial pressure of carbon dioxide between external jugular vein and superior vena cava | 1 hour | 
| Relationship between superior vena cava central venous and external jugular venous oxygen saturation | Linear regression to determine prediction equation between superior vena cava oxygen saturation and external jugular vein oxygen saturation | 1 hour | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
central venous oxygen saturation, external jugular venous oxygen saturation, central venous catheter, external jugular vein, internal jugular vein, superior vena cava oxygen saturation