Optimal Level of PEEP in Protective One-lung Ventilation

Study Overview
=================
Brief Summary
-----------------
Protective ventilation strategy has been widely applied in the field of thoracic surgery requiring one-lung ventilation to reduce postoperative pulmonary complications. Low tidal volume, positive end-expiratory pressure (PEEP), and intermittent recruitment maneuver are key components of protective ventilation strategy. Recent evidence suggests that a tidal volume of 4-5 ml/kg should be applied during protective one-lung ventilation. However, optimal level of PEEP is still unclear. This study aims to investigate optimal level of PEEP to minimize postoperative atelectasis by comparing modified lung ultrasound score in patients applied protective one-lung ventilation using PEEP of 3, 6, or 9 cm of water during thoracic surgery.

Official Title
-----------------
Optimal Level of Positive End-expiratory Pressure to Reduce Postoperative Atelectasis After Lung Resection With Protective One-lung Ventilation

Conditions
-----------------
Video-assisted Thoracic Surgery, Postoperative Atelectasis, Positive End-expiratory Pressure

Intervention / Treatment
-----------------
* Procedure: PEEP 3 cm of water
* Procedure: PEEP 6 cm of water
* Procedure: PEEP 9 cm of water


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients undergoing Video-assisted Thoracic Surgery under one-lung ventilation Exclusion Criteria: Moderate to severe obstructive/restrictive pattern in preoperative pulmonary function test Chronic kidney disease Coronary artery disease Pulmonary hypertension Bilateral lung surgery Conversion to thoracotomy American Society of Anesthesiologists physical status IV or more Refusal to participate

Ages Eligible for Study
-----------------
Minimum Age: 19 Years
Maximum Age: 80 Years

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

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

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

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: PEEP 3 cm of water<br>Patients allocated in this group will be applied protective one-lung ventilation using tidal volume of 5 ml/kg predicted body weight with PEEP of 3 cm of water during thoracic surgery. | Procedure: PEEP 3 cm of water<br>* PEEP of 3 cm of water will be applied during one-lung ventilation.<br>|
| Experimental: PEEP 6 cm of water<br>Patients allocated in this group will be applied protective one-lung ventilation using tidal volume of 5 ml/kg predicted body weight with PEEP of 6 cm of water during thoracic surgery. | Procedure: PEEP 6 cm of water<br>* PEEP of 6 cm of water will be applied during one-lung ventilation.<br>|
| Experimental: PEEP 9 cm of water<br>Patients allocated in this group will be applied protective one-lung ventilation using tidal volume of 5 ml/kg predicted body weight with PEEP of 9 cm of water during thoracic surgery. | Procedure: PEEP 9 cm of water<br>* PEEP of 9 cm of water will be applied during one-lung ventilation.<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Modified lung ultrasound score | The score is calculated by adding up the 12 individual quadrant scores assessed using lung ultrasound. | Postoperative 1 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intraoperative desaturation | Oxygen saturation by pulse oximetry <95% during one-lung ventilation | Average time of 60-90 minutes | 
| Intraoperative partial pressure of arterial oxygen/fraction of inspired oxygen ratio | partial pressure of arterial oxygen/fraction of inspired oxygen ratio during one-lung ventilation | Average time of 60-90 minutes | 
| Postoperative desaturation | Oxygen saturation by pulse oximetry <95% | Postoperative 24 hours | 
| plasma Tumor Necrosis Factor-α | proinflammatory cytokine | 10 minutes after initiation of one-lung ventilation | 
| plasma Interleukin-6 | proinflammatory cytokine | 10 minutes after initiation of one-lung ventilation | 
| plasma Interleukin-10 | anti-inflammatory cytokine | 10 minutes after initiation of one-lung ventilation | 
| Postoperative pulmonary complication | Composite outcome of atelectasis, pneumonia, acute respiratory distress syndrome, or pulmonary aspiration | Postoperative 7 days | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Protective ventilation, One-lung ventilation