Study of Atelectasis by Electrical Impedance Tomography

Study Overview
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Brief Summary
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The goal of this interventional study is to learn about the effects of different positions on the occurrence, regional distribution and reversibility of atelectasis by using a PulmoVista 500 monitor (Dräger. 23542 Lübeck), during general anesthesia with mechanical ventilation. The main questions it aims to answer are: The increase in atelectasis after induction of general anesthesia in supine and Trendelenburg position compared with baseline (spontaneous breathing) The eventual possibility of reversal of atelectasis caused by general anesthesia and Trendelenburg position by reverse Trendelenburg position and recruitment manœuvre. Participants will be adult, autonomous and able to express their will, undergoing elective gynecological or urological surgery in the extended Trendelenburg position.

Official Title
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Study of Atelectasis by Electrical Impedance Tomography and the Effects of Different Positions on Their Occurrence, Reversibility and Regional Distribution, During General Anesthesia

Conditions
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Gynecologic Surgical Procedures, Urologic Surgical Procedures

Intervention / Treatment
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* Other: Recruitment maneuver (RM)
* Other: Reverse Trend (REV TREND)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult subjects over eighteen years old; Requiring laparoscopic gynecological, urological or digestive surgery; Surgery requiring Trendelenburg position and tracheal intubation. Exclusion Criteria: Emergency operation; Thoracic surgery; Pulmonary, cardiac pathology; Pregnant woman; BMI > 30; Comorbidities defined as an American Society of Anesthesiologists physical condition greater than 2; Language barrier; Refusal of consent.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 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: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: 1st measurement (T0-SPONT): in spontaneous ventilation. Induction, intubation and mechanical ventilation for 5 minutes. 2nd measurement (T1-LYING): after induction. Trendelenburg 30° and ventilatory constant parameters. 3rd measurement (T2-TREND): after 5 minutes of Trendelenburg. Division into 2 groups according to randomization: I. Supine position and recruitment manoeuvre. 4th measurement after 5 minutes. (T3-RM) II. Either put in the Anti Trendelenburg position. 4th measurement after 5 minutes. (TREND Q3- REV) Horizontal supine position and surgical incision.
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Recruitment maneuver (RM) group 1<br> | Other: Recruitment maneuver (RM)<br>* performance of a recruitment maneuver of 30 cm H20 for 30 seconds and measurement of electrical impedance<br>|
| Active Comparator: Reverse Trend (REV TREND) group 2<br> | Other: Reverse Trend (REV TREND)<br>* Place the patient in the reverse trendelenburg position and measuring the electrical impedance after 5 minutes<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the percentage of atelectasis after induction of general anesthesia (Time 1) | percentage | from the base measure to time 1 (10 minutes) | 
| the percentage of atelectasis after being positioned in the trendelenburg position (Time 2) | percentage | from the base measure to time 2 (15 minutes) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The eventual possibility of reversal of atelectasis by reverse Trendelenburg position and recruitment maneuver (Time 3) | percentage | from the base measure to time 3 (20 minutes) |