The Affecting Factors on Airway Temperature and Moisture

Study Overview
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Brief Summary
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There is no literature information about the flow rate of fresh gas mixture (air+O2) in the patients who underwent general anesthesia. Different flow rates of fresh gas mixture are used in both the investigator's hospital and the experiences of the anesthesiologists. It is aimed to study the effects of different fresh gas flow rates on the rate of temperature and moisture of the airway of patients who underwent general anesthesia.

Detailed Description
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Under physiological conditions, inhaled air is heated and humidified as it passes through the nose and upper airways until reaching the alveoli. This mechanism is bypassed by endotracheal intubation. Ventilation with dry and cold compressed gases leads to loss of water and heat from the respiratory tract. Drying of the respiratory tract can lead to destruction of the cilia and mucous membranes, resulting in decreased mucociliary transport and increased concentration of secretions.There is no definitive literature on fresh gas mix (oxygen + air) flow rates in patients under general anesthesia. This study aimed to investigate whether two fresh gas flow rates routinely employed in the authors' practice affected airway temperature and humidity.

Official Title
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The Effects of Different Fresh Gas Flows and Different Anesthetics on Airway Temperature and Moisture in Patients Who Underwent General Anesthesia

Conditions
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General Anesthesia

Intervention / Treatment
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* Other: We will observe and evaluate the temperature and moisture in the respiratory circuit by a thermo-hygrometer.


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients aged 18-65 years underwent general anesthesia - Exclusion Criteria:admitted to emergency and trauma, history of advanced cardiac disease, cigarette use ≥ 3 packet/day, pulmonary parenchymal disease such as malignancy or chronic obstructive pulmonary disease (COPD), history of thyroid disease, body mass index (BMI) greater than 30 kg/m2, alcohol and substance addiction, mentally deficiency, pregnancy or postpartum, fever and infection, drug use such that would influence thermoregulation such as vasodilators, hemorrhage > 5 mL/kg, and patients who declined to participate. -

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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 |
| --- | --- |
| 3 lt/min<br>Patients in the study were divided into two main groups according to the standard fresh gas flow administered (3-6 L/min). Each main group was then divided into subgroups as follows: sevoflurane + remifentanil, desflurane + remifentanil, or propofol + remifentanil (TIVA). These six groups were further divided into two groups according to use or non-use of a heat and moisture exchanger (HME) filter. | Other: We will observe and evaluate the temperature and moisture in the respiratory circuit by a thermo-hygrometer.<br> <br> |
| 6 lt/min<br>Patients in the study were divided into two main groups according to the standard fresh gas flow administered (3-6 L/min). Each main group was then divided into subgroups as follows: sevoflurane + remifentanil, desflurane + remifentanil, or propofol + remifentanil (TIVA). These six groups were further divided into two groups according to use or non-use of a heat and moisture exchanger (HME) filter. | Other: We will observe and evaluate the temperature and moisture in the respiratory circuit by a thermo-hygrometer.<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Affect of two fresh gas flow rates (3lt/ 6lt min) on patients' airway temperature and humidity. | We will evaluate if different fresh gas flows effect on patients' airway temperature and moisture. We will evaluate by using a thermo-hygrometer fixed on anesthesia circuit. | 2016-2018 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Affect of different anesthetic gases (sevoflurane, desflurane) and drugs (propofol)on patients' airway temperature and humidity. | We will evaluate if different anesthetic gases (sevoflurane, desflurane) and drugs (propofol) effect on patients' airway temperature and moisture. We will evaluate by using a thermo-hygrometer fixed on anesthesia circuit. | 2016-2018 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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general anesthesia, fresh gas, moisture, temperature, respiratory circuit