Effects of Iloprost on Oxygenation During One-lung Ventilation in Supine-positioned Patients

Study Overview
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Brief Summary
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One-lung ventilation (OLV) is essential during mediastinal mass excision. However, OLV induces a drastic increase of intrapulmonary shunt due to maintained pulmonary perfusion through the nonventilated lung. In addition, it is reported that supine positioning of patient during OLV, which is required during mediastinal mass excision, results in worse oxygenation than lateral decubitus positioning. Iloprost is a prostaglandin analogue and when inhaled during OLV, it acts selectively on the pulmonary vasculature, reducing pulmonary vascular resistance of well-ventilated lung and thereby alleviating ventilation-perfusion mismatch. The purpose of this study is to evaluate the effects of inhaled iloprost on oxygenation during one-lung ventilation in patients undergoing mediastinal mass excision.

Official Title
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Effects of Iloprost on Oxygenation During One-lung Ventilation in Supine-positioned Patients

Conditions
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Mediastinal Mass

Intervention / Treatment
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* Drug: 5ml of inhaled normal saline
* Drug: 20μg (2ml) of inhaled iloprost (Ventavis®) and 3ml of inhaled normal saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients scheduled for Video-assisted thoracoscopic surgery (VATS) mediastinal mass excision Patient age from 20 to 80 American Society of Anaesthesiologists (ASA) physical status classification II III Exclusion Criteria: Chronic obstructive pulmonary disease (COPD) with Forced expiratory volume in 1 second (FEV1) to Forced vital capacity (FVC) ratio < 0.7 and percentage of predicted FEV1 ≤ 80% Diffusing capacity of carbon monoxide (DLCO) < 80% Aspartate transaminase (AST) level ≥100 IU/mL or alanine transaminase (ALT) ≥ level 50 IU/L Creatinine clearance ≤ 30mL/min Congestive heart failure, arrhythmia Unstable angina, coronary artery occlusive disease (CAOD), history of myocardial infarction within 6 months Pulmonary edema, pulmonary arterial hypertension Allergic to prostaglandin or prostacyclin analogue Patients with peptic ulcer bleeding, trauma, intracranial hemorrhage History of cerebrovascular disease (e.g. transient ischemic attack, stroke) within 3 months Valvular heart disease Pregnant women

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Control group<br> | Drug: 5ml of inhaled normal saline<br>* After the initiation of OLV, 5ml of normal saline is inhaled for 20 minutes using ultrasonic nebulizer, which is connected to the inspiratory limb of the ventilator system. Arterial blood gas analysis is performed 20 minutes after the completion of drug inhalation.<br>|
| Experimental: Iloprost group<br> | Drug: 20μg (2ml) of inhaled iloprost (Ventavis®) and 3ml of inhaled normal saline<br>* After the initiation of OLV, mixture of iloprost 2ml and normal saline 3ml is inhaled for 20 minutes using ultrasonic nebulizer, which is connected to the inspiratory limb of the ventilator system. Arterial blood gas analysis is performed 20 minutes after the completion of drug inhalation.<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) to FiO2 (fraction of inspired oxygen) ratio (P/F ratio) | The P/F ratio is a widely-used objective tool to identify hypoxemic respiratory failure when supplemental oxygen has been administered. It can be used to evaluate the effect of iloprost on oxygenation during OLV. | Twenty minutes after the completion of drug inhalation |