Effectiveness of Lung Sono in One-lung Ventilation

Study Overview
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Brief Summary
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To observe the effectiveness of ultrasound-guided alveolar recruitment in thoracic surgery with one-lung ventilation(OLV).

Detailed Description
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One-lung ventilation(OLV) is essential in thoracic surgery for patient safety and better surgical view. However, pulmonary complications such as hypoxemia may be caused by OLV which might be preventable with adequate alveolar recruitment and positive end-expiratory pressure(PEEP). Alveolar recruitment has been performed with conventional methods without diagnostic tools in clinical setting. Ultrasound is a non-invasive, radiation-free device with high accuracy for the diagnosis of lung atelectasis. There are a few reports regarding the usefulness of lung ultrasound in other surgeries, but not in thoracic surgeries with OLV. Thus, investigators designed a study to observe the effectiveness of ultrasound-guided alveolar recruitment in thoracic surgery with OLV.

Official Title
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Effectiveness of Ultrasound-guided Alveolar Recruitment in Thoracic Surgery With One-lung Ventilation

Conditions
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One Lung Ventilation

Intervention / Treatment
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* Procedure: Lung-sono guided


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Elective thoracic surgery which requires one-lung ventilation with lateral decubitus position Exclusion Criteria: Patients who refuse to agree Previous lung surgical history History of pneumothorax or bullae Severe cardiopulmonary disease, COPD Operation time < 1hr

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 80 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Lung-sono guided<br>Before starting one-lung ventilation, alveolar recruitment is performed under the examination with ultrasound. Find the minimal airway pressure that actually starts to resolve the observed atelectasis. Repeat alveolar recruitment with the minimal pressure untill the atlelectasis is not visible. | Procedure: Lung-sono guided<br>* The patient undergoing thoracic surgery is intubated with double lumen tube after induction of general anesthesia with propofol and remifentanil. In the intervention group, alveolar recruitment is performed to the non-surgical side of lung under examination with ultrasound just after anesthesia induction. During the gradual increment in the pressure of recruitment, the anesthesiologist can find the opening pressure that means the minimal pressure at which observed atelectasis starts to disappear. Then, alveolar recruitment is performed with the opening pressure until the atelectasis is not visible.<br>|
| No Intervention: Conventional<br>Before starting one-lung ventilation, alveolar recruitment is performed with the pressure of 30mmHg for 10 seconds which is a conventional method. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of desaturation | SpO2<95% | intraoperative | 
| P/F ratio | PaO2/FiO2 ratio | 30 minutes after one-lung ventilation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lung ultrasound score | Lung ultrasound score of atelectasis | just after anesthesia induction, end of surgery | 
| Alveolar dead space | (PaCO2-PetCO2)xVt/PaCO2 | 30 minutes after one-lung ventilation | 
| Pulmonary complications | respiratory infection, respiratory failure, pleural effusion, atelectasis, pneumothorax, atelectasis, bronchospasm, aspiration pneumonitis | intraoperative, during hospital stay(an average of 3 days) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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One lung ventilation, Lung ultrasound, Alveolar recruitment