The Affecting Factors on Airway Temperature and Moisture

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

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.

Study Overview

• Status: Completed
• Conditions: General Anesthesia
• Intervention / Treatment: Other: We will observe and evaluate the temperature and moisture in the respiratory circuit by a thermo-hygrometer.

Detailed Description

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.

• Study Type: Observational
• Enrollment (Actual): 240

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients who were aged between 18-65 years and underwent surgery with general anesthesia.

Description

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.

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Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
3 lt/min; 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.
6 lt/min; 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.

What is the study measuring?

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

Collaborators and Investigators

• Sponsor: Selcuk University

Publications and helpful links

General Publications

• Ozcan IG, Onal O, Ozdemirkan A, Saltali A, Sari M. Effects of different fresh gas flows and different anesthetics on airway temperature and humidity in surgical patients: a prospective observational study. Med Gas Res. 2022 Jul-Sep;12(3):83-90. doi: 10.4103/2045-9912.330691.

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2016
• Primary Completion (Actual): April 1, 2018
• Study Completion (Actual): April 1, 2018

Study Registration Dates

• First Submitted: December 17, 2019
• First Submitted That Met QC Criteria: December 18, 2019
• First Posted (Actual): December 19, 2019

Study Record Updates

• Last Update Posted (Actual): December 20, 2019
• Last Update Submitted That Met QC Criteria: December 18, 2019
• Last Verified: December 1, 2019

More Information

Terms related to this study

• Keywords: general anesthesia; temperature; moisture; fresh gas; respiratory circuit
• Other Study ID Numbers: E.90598

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The type(s) of supporting information that will be shared, in addition to the individual participant data set and data dictionaries for the IPD itself.
• IPD Sharing Time Frame: The IPD and any additional supporting information will become available in starting 2 months after publication.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No