Temperature and Humidity Among Different Anesthesia Work-station

Study Overview
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Brief Summary
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The effects of preserving humidity and temperature by low flow anesthesia are different in each other anesthesia workstation.

Detailed Description
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The fresh gas flow(FGF) is dry and cold in old fashioned anesthesia machine, especially at high folw (above 1 L/min). To the contrary, it has been assumed that the heat and humidity of FGF may be preserved using low FGF (below 1 L/min) during anesthesia or new anesthesia work station. However, it has not been proved yet. We hypothesized that the heat and moisture of FGF may be different in various FGF rate during anesthesia. In addition, it may be different in accordance to anesthesia work station. Therefore, we planed prospective observational study that will demonstrate that the difference of heat and moisture of FGF in different anesthesia work station (Excel; 1st generation anesthesia machine of Datex-Ohmeda Corp., Avance; 2nd generation anesthesia work station of Datex-Ohmeda Corp., Cato; 2nd generation generation anesthesia work station of Drager, Primus; 3rd generation generation anesthesia work station of Drager) and different FGF (0.5, 1, 4 L/min)

Official Title
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Comparison of Heat and Humidity Conservation Among Different Anesthesia Workstation and Different Flow Rate.

Conditions
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Humidity, Temperature

Intervention / Treatment
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* Device: Datex Ohmeda excel anesthesia machine
* Device: Datex Ohmeda Avance anesthesia work-station
* Device: Drager Cato anesthesia work-station
* Device: Drager Primus anesthesia work-station


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients who planned more than 2 hour operation under general anesthesia ASA class 1,2 blood loss less than 500ml Exclusion Criteria: acute/chronic cardiac or respiratory disease

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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: Health Services Research
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: humidity<br> | Device: Datex Ohmeda excel anesthesia machine<br>* maintain one of following fresh gas flow, 1 or 4 L/min (nitrous oxide:oxygen =1:1) during 2 hour with using Datex Ohmeda excel anesthesia machine after draping complete<br>* Other names: Excel;Device: Datex Ohmeda Avance anesthesia work-station<br>* maintain one of following fresh gas flow, 0.5 or 1 or 4 L/min (nitrous oxide:oxygen =1:1) during 2 hour with using Datex Ohmeda Avance anesthesia machine after draping complete<br>* Other names: Avance;Device: Drager Cato anesthesia work-station<br>* maintain one of following fresh gas flow, 0.5 or 1 or 4 L/min (nitrous oxide:oxygen =1:1) during 2 hour with using Drager Cato anesthesia work-station after draping complete<br>* Other names: Cato;Device: Drager Primus anesthesia work-station<br>* maintain one of following fresh gas flow, 0.5 or 1 or 4 L/min (nitrous oxide:oxygen =1:1) during 2 hour with using Drager Primus anesthesia work-station after draping complete<br>* Other names: Primus;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| absolute humidity at both limb of breathing circuit just distal portion of Y-piece | time point 1; base line value (fresh gas flow(FGF); 8L/min) time point 2; 5 mintues(min) after FGF change to predetermined level time point 3; 10 min after FGF change to predetermined level time point 4; 15 min after FGF change to predetermined level time point 5; 30 min after FGF change to predetermined level time point 6; 45 min after FGF change to predetermined level time point 7; 60 min time point 8; 75 min time point 9; 90 min time point 10; 105 min time point 11; 120 min | time point 1-11 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| patient body temperature(BT) | measure BT using esophageal temperature probe each time points are same as primary outcome | time point 1 -11 | 
| temperature at both limb of breathing circuit just distal portion of Y-piece | the time points are same as primary outcome | time point 1- 11 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Humidity, Temperature, Low Flow Anesthesia