Effects of Positive End-Expiratory Pressure on Biventricular Function During One-Lung Ventilation

Study Overview
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Brief Summary
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One lung ventilation (OLV) is essential during thoracic surgery. During OLV, intrapulmonary shunt can be increased resulting hypoxemia. Wang et al measured intrapulmonary shunt by transesophageal echocardiography. Although OLV technique had been advanced so far, hypoxemia during OLV reaches about 10% in spite of inspired oxygen fraction 100%. Applying PEEP(Positive End-expiratory Pressure) at dependent lung and CPAP at non-dependent lung can mitigate the hypoxemia. Above all, PEEP can be easily applicable. However, there are controversial studies whether it is supportive or not. In this prospective, cross-over study, the investigators are planning to investigate the effects of PEEP on intrapulmonary shunt, oxygenation and cardiac function as well.

Official Title
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Effects of Positive End-Expiratory Pressure on Biventricular Function During One-Lung Ventilation: a Randomized Crossover Study

Conditions
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Lung Cancer

Intervention / Treatment
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* Procedure: PEEP


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: scheduled for VATS lobectomy 40 ≤ age ≤ 80 American Society of Anaesthesiologists(ASA) physical status classification I III Exclusion Criteria: American Society of Anaesthesiologists(ASA) physical status classification IV NYHA class III IV Severe obstructive lung disease and/or restrictive lung disease patients those with end-organ diseases (i.e. heart failure, respiratory failure, hepatic failure, renal failure) arrhythmia esophageal varix pregnant women

Ages Eligible for Study
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Minimum Age: 40 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: Diagnostic
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: PEEP 0 cmH2O<br>PEEP 0 cmH2O (zero end expiratory pressure, ZEEP) | Procedure: PEEP<br>* After induction of anesthesia, including insertion of TEE probe, change position from supine to lateral position. Measure ABGA and cardiac indices for the baseline value. Apply each PEEP (0, 5, 10 cmH2O) serially at the random order. 6 sequences (0->5->10, 0->10->5, 5->10->0, 5->0->10, 10->5->0, 10->0->5) are equally applied to 6 patients (total 6x6=36 patients) who agreed to this study. Measure ABGA and cardiac indices after 20 min at each step of peep apply(3 times).<br>* Other names: Positive EndExpiratory Pressure breathing(PEEP);|
| Experimental: PEEP 5 cmH2O<br> | Procedure: PEEP<br>* After induction of anesthesia, including insertion of TEE probe, change position from supine to lateral position. Measure ABGA and cardiac indices for the baseline value. Apply each PEEP (0, 5, 10 cmH2O) serially at the random order. 6 sequences (0->5->10, 0->10->5, 5->10->0, 5->0->10, 10->5->0, 10->0->5) are equally applied to 6 patients (total 6x6=36 patients) who agreed to this study. Measure ABGA and cardiac indices after 20 min at each step of peep apply(3 times).<br>* Other names: Positive EndExpiratory Pressure breathing(PEEP);|
| Experimental: EEP 10 cmH2O<br> | Procedure: PEEP<br>* After induction of anesthesia, including insertion of TEE probe, change position from supine to lateral position. Measure ABGA and cardiac indices for the baseline value. Apply each PEEP (0, 5, 10 cmH2O) serially at the random order. 6 sequences (0->5->10, 0->10->5, 5->10->0, 5->0->10, 10->5->0, 10->0->5) are equally applied to 6 patients (total 6x6=36 patients) who agreed to this study. Measure ABGA and cardiac indices after 20 min at each step of peep apply(3 times).<br>* Other names: Positive EndExpiratory Pressure breathing(PEEP);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the effect of differential PEEP (0, 5, 10 cmH2O) by PaO2(P/F ratio) |  | 20 minutes after each PEEP apply | 
| Cardiac function | cardiac function : Tei index | 20 minutes after each PEEP apply |