Effect of Iloprost on Pulmonary Oxygenation in Patients With Low Diffusing Capacity 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. Although OLV technique had been advanced so far, hypoxemia during OLV reaches about 10% in spite of inspired oxygen fraction 100%. Iloprost is a prostaglandin analogue used for pulmonary hypertension, which can decrease pulmonary artery resistance by selectively dilating pulmonary artery. In this prospective, randomized, double blind study, investigators are planning to investigate the effects of iloprost on respiratory physiology (intrapulmonary shunt, deadspace, oxygenation, etc).

Conditions
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Lung Cancer

Intervention / Treatment
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* Drug: iloprost
* Drug: normal saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: scheduled for Video-assisted thoracoscopic surgery (VATS) lobectomy 40 < age < 80 American Society of Anaesthesiologists (ASA) physical status classification I III diffusing capacity (DLCO) <75% at pre op. pulmonary function test Exclusion Criteria: American Society of Anaesthesiologists (ASA) physical status classification IV New York Heart Association (NYHA) class III IV Severe obstructive lung disease and/or restrictive lung disease patients patients with end-organ diseases (i.e. heart failure, respiratory failure, hepatic failure, renal failure) arrhythmia pregnant women disease that can influence the DLCO result (anemia, pulmonary vascular disease)

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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: iloprost group<br>iloprost inhalation group | Drug: iloprost<br>* 20μg(2ml) of inhaled iloprost (Ventavis®) When anesthesia induction finishes, change patients' position from supine to lateral position and measure arterial blood gas analysis (ABGA), venous blood gas analysis (VBGA) while two lung is ventilated. After 20 minutes of applying one lung ventilation, measure ABGA. Apply iloprost or normal saline inhalation for each iloprost and control group and measure ABGA at the time of 20 min and 40 min after iloprost (or normal saline) inhalation has finished.<br>|
| Placebo Comparator: control group<br>normal saline inhalation group | Drug: normal saline<br>* 20μg(2ml) of inhaled normal saline When anesthesia induction finishes, change patients' position from supine to lateral position and measure ABGA, VBGA while two lung is ventilated. After 20 minutes of applying one lung ventilation, measure ABGA. Apply iloprost or normal saline inhalation for each iloprost and control group and measure ABGA at the time of 20 min and 40 min after iloprost (or normal saline) inhalation has finished.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PaO2(partial pressure of arterial oxygen) ratio |  | 40 minutes after iloprost inhalation | 
| incidence of intrapulmonary shunt |  | 40 minutes after iloprost inhalation |