Thermal Insulation System in Inadvertent Hypothermia

Study Overview
=================
Brief Summary
-----------------
This study compares the effectiveness of a new layered thermal insulation system (SIT-3c) versus the traditional thermal body protection (warmed forced air system) for patients under total knee arthroplasty, during the intra-operative phase.

Detailed Description
-----------------
Protecting patients from the cold in the operating room is a complex problem that has encouraged the search for better and more effective thermal protection systems. Some disadvantages have been observed in the daily use of the recommended thermal protection system (forced warm air). This study intends to design and evaluate the effectiveness of a three-layer thermal insulation system, comparing its effect with the forced warm air system on temperature variation, shivering incidence and comfort perception, in patients undergoing total knee arthroplasty under neuro-axial anesthesia, during the intra-operative phase. Participants are randomly assigned to the experimental group (EG) or control group (CG). The experimental group receives as a skin protection the three-layer thermal insulation system (SIT-3c) and the control group receives the usual recommended system (forced warm air). Both systems are placed at the entrance to the operating room and held on patients during the entire intra-operative phase.

Official Title
-----------------
Efficacy of a Thermal Insulation System in Inadvertent Hypothermia and Perioperative Comfort

Conditions
-----------------
Perioperative Hypothermia

Intervention / Treatment
-----------------
* Device: Layered thermal insulation system


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients aged over 18 years, with the diagnosis of gonarthrosis, to undergo total elective knee arthroplasty, under neuroaxial anesthesia, who agreed to participate in the study. Exclusion Criteria: With hypothermia or hyperthermia, scheduled for general anesthesia, pregnancy

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

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

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

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Thermal insulation system<br>experimental: layered thermal insulation system The system was applied in the upper body to the entrance of the operating room and remained until the exit of the same room. The test included the evaluation of temperature, tremors and the visual perception of thermal comfort in 6 moments (T1 - reference temperature - at the entrance of the anesthetic induction room, T2 - at the entrance to the operating room, T3, T4 and T5 - fifteen , thirty and forty-five minutes after the start of surgery, and T6 - leaving the operating room) | Device: Layered thermal insulation system<br>* No other intervention<br>|
| No Intervention: Forced air active warming<br>Control: the same procedures as in the experiment group, were carried out in the control group, except for the intervention. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in tympanic temperature (T1) | Method of assessment - the TTS-400 thermometer, Smiths Medical was used | Baseline (entrance in the operating room) | 
| Changes in tympanic temperature (T2) | Method of assessment - the TTS-400 thermometer, Smiths Medical was used | immediately after anesthesia | 
| Changes in tympanic temperature (T3) | Method of assessment - the TTS-400 thermometer, Smiths Medical was used | 15 minutes after beginning surgery | 
| Changes in tympanic temperature (T4) | Method of assessment - the TTS-400 thermometer, Smiths Medical was used | 30 minutes after beginning surgery | 
| Changes in tympanic temperature (T5) | Method of assessment - the TTS-400 thermometer, Smiths Medical was used | 45 minutes after beginning surgery | 
| Changes in tympanic temperature (T6) | Method of assessment - the TTS-400 thermometer, Smiths Medical was used | Up to 10 min after the end of surgery (living the operating room) | 
| Changes in shivering (T1) | Method of assessment - the Leslie and Sessler Scale, which measures tremors at three levels (0 - no tremors; 1 - slight tremors; 2 - vigorous tremors). | Baseline (entrance in the operating room) | 
| Changes in shivering (T2) | Method of assessment - the Leslie and Sessler Scale, which measures tremors at three levels (0 - no tremors; 1 - slight tremors; 2 - vigorous tremors). | immediately after anesthesia | 
| Changes in shivering (T3) | Method of assessment - the Leslie and Sessler Scale, which measures tremors at three levels (0 - no tremors; 1 - slight tremors; 2 - vigorous tremors). | 15 minutes after beginning surgery | 
| Changes in shivering (T4) | Method of assessment - the Leslie and Sessler Scale, which measures tremors at three levels (0 - no tremors; 1 - slight tremors; 2 - vigorous tremors). | 30 minutes after beginning surgery | 
| Changes in shivering (T5) | Method of assessment - the Leslie and Sessler Scale, which measures tremors at three levels (0 - no tremors; 1 - slight tremors; 2 - vigorous tremors). | 45 minutes after beginning surgery | 
| Changes in shivering (T6) | Method of assessment - the Leslie and Sessler Scale, which measures tremors at three levels (0 - no tremors; 1 - slight tremors; 2 - vigorous tremors). | Up to 10 min after the end of surgery (living the operating room) | 
| Changes in visual perception of Thermal comfort (T1) | Method of assessment - the Visual Comfort Scale, which measures the perception of thermal comfort in two components: numerical (1 to 10) and visual (5 faces). The numerical component varies between 0 (very cold) and 10 (very hot), the value of the thermal neutrality, which means thermal comfort, identified in point 5; and the visual component where five expressive faces are presented. The first one, located between the numbers 0-2, shows strong cold discomfort, the second, located between 2-4, expressed cold discomfort, the third, located in the area of the number 5, expresses a sensation of thermal comfort, the fourth, located between the numbers 6-8, reveals heat discomfort and the fifth, located between 8-10, shows strong heat discomfort. | Baseline (entrance in the operating room) | 
| Changes in visual perception of Thermal comfort (T2) | Method of assessment - the Visual Comfort Scale, which measures the perception of thermal comfort in two components: numerical (1 to 10) and visual (5 faces). The numerical component varies between 0 (very cold) and 10 (very hot), the value of the thermal neutrality, which means thermal comfort, identified in point 5; and the visual component where five expressive faces are presented. The first one, located between the numbers 0-2, shows strong cold discomfort, the second, located between 2-4, expressed cold discomfort, the third, located in the area of the number 5, expresses a sensation of thermal comfort, the fourth, located between the numbers 6-8, reveals heat discomfort and the fifth, located between 8-10, shows strong heat discomfort. | immediately after anesthesia | 
| Changes in visual perception of Thermal comfort (T3) | Method of assessment - the Visual Comfort Scale, which measures the perception of thermal comfort in two components: numerical (1 to 10) and visual (5 faces). The numerical component varies between 0 (very cold) and 10 (very hot), the value of the thermal neutrality, which means thermal comfort, identified in point 5; and the visual component where five expressive faces are presented. The first one, located between the numbers 0-2, shows strong cold discomfort, the second, located between 2-4, expressed cold discomfort, the third, located in the area of the number 5, expresses a sensation of thermal comfort, the fourth, located between the numbers 6-8, reveals heat discomfort and the fifth, located between 8-10, shows strong heat discomfort. | 15 minutes after beginning surgery | 
| Changes in visual perception of Thermal comfort (T4) | Method of assessment - the Visual Comfort Scale, which measures the perception of thermal comfort in two components: numerical (1 to 10) and visual (5 faces). The numerical component varies between 0 (very cold) and 10 (very hot), the value of the thermal neutrality, which means thermal comfort, identified in point 5; and the visual component where five expressive faces are presented. The first one, located between the numbers 0-2, shows strong cold discomfort, the second, located between 2-4, expressed cold discomfort, the third, located in the area of the number 5, expresses a sensation of thermal comfort, the fourth, located between the numbers 6-8, reveals heat discomfort and the fifth, located between 8-10, shows strong heat discomfort. | 30 minutes after beginning surgery | 
| Changes in visual perception of Thermal comfort (T5) | Method of assessment - the Visual Comfort Scale, which measures the perception of thermal comfort in two components: numerical (1 to 10) and visual (5 faces). The numerical component varies between 0 (very cold) and 10 (very hot), the value of the thermal neutrality, which means thermal comfort, identified in point 5; and the visual component where five expressive faces are presented. The first one, located between the numbers 0-2, shows strong cold discomfort, the second, located between 2-4, expressed cold discomfort, the third, located in the area of the number 5, expresses a sensation of thermal comfort, the fourth, located between the numbers 6-8, reveals heat discomfort and the fifth, located between 8-10, shows strong heat discomfort. | 45 minutes after beginning surgery | 
| Changes in visual perception of Thermal comfort (T6) | Method of assessment - the Visual Comfort Scale, which measures the perception of thermal comfort in two components: numerical (1 to 10) and visual (5 faces). The numerical component varies between 0 (very cold) and 10 (very hot), the value of the thermal neutrality, which means thermal comfort, identified in point 5; and the visual component where five expressive faces are presented. The first one, located between the numbers 0-2, shows strong cold discomfort, the second, located between 2-4, expressed cold discomfort, the third, located in the area of the number 5, expresses a sensation of thermal comfort, the fourth, located between the numbers 6-8, reveals heat discomfort and the fifth, located between 8-10, shows strong heat discomfort. | Up to 10 min after the end of surgery (living the operating room) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| General intraoperative comfort | Method of assessment - the Perioperative Comfort Scale, based on Kolcaba´s theory, composed of 15 items answered by a six-point Likert scale ranging from 1 (totally disagree) to 6 (I totally agree), which measures general aspects of comfort in three dimensions: relief, ease and transcendence. | 30 minutes after beginning surgery | 
| Thermal intraoperative comfort | Method of assessment - the Thermal Comfort Scale, composed of 9 items answered by a six-point Likert scale ranging from 1 (totally disagree) to 6 (I totally agree), which measures thermal aspects of comfort in two dimensions: physical and emotional. | 30 minutes after beginning surgery | 
| Ergonomic comfort | Method of assessment - the Ergonomic questionnaire, composed of 10 items answered by a five-point Likert scale ranging from 1 (not at all comfortable) to 5 (very comfortable). | 30 minutes after beginning surgery | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
perioperative hypothermia, thermal insulation, perioperative comfort