The Effect of Permissive Hypercapnia on Oxygenation and Post-operative Pulmonary Complication During One-lung Ventilation

Study Overview
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Brief Summary
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Permissive hypercapnia increased the survival rate in patients with acute respiratory distress syndrome (ARDS) who required mechanical ventilation in critical care medicine. This has been explained by its association with ventilator induced lung injury. Since then, a protective lung ventilation strategy has been very important, with a low tidal volume of 4-6 ml/kg. Patients undergoing surgery will inevitably require mechanical ventilation. In particular, patients undergoing one lung ventilation for thoracic surgery may have increased airway pressure and a greater chance of ventilator induced lung injury. Recently, protective lung ventilation has been applied to patients undergoing one ung ventilation during thoracic surgery. The purpose of this study is to evaluate the difference in the degree of pulmonary oxygenation and the incidence of postoperative pulmonary complications in hypercapnia induced by controlling the respiratory rate with a constant tidal volume.

Official Title
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The Effect of Permissive Hypercapnia on Oxygenation and Post-operative Pulmonary Complication During One-lung Ventilation : Prospective, Randomized Controlled Study

Conditions
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Thoracic Surgery

Intervention / Treatment
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* Other: group 40
* Other: group 50
* Other: group 60


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients aged 40-80 years who are planning to have thoracoscopic single lobectomy or segmentectomy with one lung ventilation during surgery. American Society of Anesthesiologists (ASA) classification 1 3 Exclusion Criteria: patients with heart failure (NYHA class III IV) patients who are having moderate obstructive lung disease or restrictive lung disease Low DLCO (< 75%) patients with brain disease history or increased ICP patients with pulmonary hypertension (mean PAP>25mmHg) patients with liver disease (AST level ≥100 IU/mL or ALT ≥ level 50 IU/L) or kidney disease (Creatine level ≥ 1.5 mg/dL) patients with pre-existing hypercapnia or metabolic acidosis body mass index (BMI) > 30 kg/m2 patients who have had contralateral lung surgery patients who cannot read explanation and consent form patients who are pregnant

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Random sampling using random numbers is divided into three groups, and the ratio of each group is 1: 1: 1.
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: group 40<br>In group 40, target PaCO2 is 40 during surgery | Other: group 40<br>* During surgery, the TV(tidal volume) should maintain 6ml/kg (ideal body weight). After position change and OLV(one lung ventilation) for operation, each patient adjusts RR(respiratory rate) to reach target PaCO2 40 ± 5mmHg. Hemodynamic records and arterial blood tests are performed at the following times: After tracheal intubation, 15 minutes after in two lung ventilatory state at the supine position (T0), after 30 minutes reaching to the target PaCO2 by adjusting RR at the lateral position starting one lung ventilation (T1), and after 60 minutes while maintaining target PaCO2 (T2).<br>|
| Experimental: group 50<br>In group 50, target PaCO2 is 50 during surgery | Other: group 50<br>* During surgery, the TV(tidal volume) should maintain 6ml/kg (ideal body weight). After position change and OLV(one lung ventilation) for operation, each patient adjusts RR(respiratory rate) to reach target PaCO2 50 ± 5mmHg. Hemodynamic records and arterial blood tests are performed at the following times: After tracheal intubation, 15 minutes after in two lung ventilatory state at the supine position (T0), after 30 minutes reaching to the target PaCO2 by adjusting RR at the lateral position starting one lung ventilation (T1), and after 60 minutes while maintaining target PaCO2 (T2).<br>|
| Experimental: group 60<br>In group 60, target PaCO2 is 60 during surgery | Other: group 60<br>* During surgery, the TV(tidal volume) should maintain 6ml/kg (ideal body weight). After position change and OLV(one lung ventilation) for operation, each patient adjusts RR(respiratory rate) to reach target PaCO2 60 ± 5mmHg. Hemodynamic records and arterial blood tests are performed at the following times: After tracheal intubation, 15 minutes after in two lung ventilatory state at the supine position (T0), after 30 minutes reaching to the target PaCO2 by adjusting RR at the lateral position starting one lung ventilation (T1), and after 60 minutes while maintaining target PaCO2 (T2).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PaO2/FiO2 ratio | (arterial oxygen partial pressure / fractional inspired oxygen) at the time of T2 (PaO2 of ABGA/FiO2) T2 | about 60 minutes after reaching to the target PaCO2 (T2) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Post-op complication: desaturation event | desaturation event (<90%) the first 3 days after surgery | first 3 days after surgery | 
| Post-op complication: oxygen therapy | necessity of oxygen therapy within the first 2 7 days after surgery hospitalized days, ICU days, expire | first 2 7 days after surgery | 
| Post-op complication | The presence or absence of post operative complication like pneumonia, acute lung injury, re-intubation, ICU admission, ventilator care, empyema, broncho-pleura fistula, air-leakage, pleural effusion, pulmonary embolism, tracheostomy, wound infection, AKI, MI, etc. | 30 days after surgery | 
| Post-op complication: hospitalized days | length of hospitalized stays CU days, expire | 30 days after surgery | 
| Post-op complication: ICU days | length of ICU stays | 30 days after surgery | 
| Dead | patient has been dead or not | 30 days after surgery |