Effects of Iloprost on Pulmonary Oxygenation in Obese Patients During One-lung Ventilation

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, the investigator is planning to investigate the effects of iloprost on respiratory physiology (intrapulmonary shunt, deadspace, oxygenation, etc) in obese patients.

Study Overview

• Status: Completed
• Conditions: Pulmonary Infection; Lung Cancer (Including Metastatic Cancer)
• Intervention / Treatment: Drug: normal saline inhalation; Drug: iloprost inhalation

• Study Type: Interventional
• Enrollment (Actual): 78
• Phase: Not Applicable

Contacts and Locations

Study Locations

• South Korea
  • Seoul, South Korea
    • Severance Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. scheduled for VATS lobectomy
2. 40 < age < 80
3. American Society of Anaesthesiologists(ASA) physical status classification I~III
4. BMI > 30 kg /m2

Exclusion Criteria:

1. American Society of Anaesthesiologists(ASA) physical status classification IV or more
2. NYHA class III~IV
3. Severe obstructive lung disease and/or restrictive lung disease patients
4. patients with end-organ diseases (i.e. heart failure, respiratory failure, hepatic failure, renal failure)
5. arrhythmia
6. pregnant women
7. pulmonary edema or pulmonary arterial hypertension
8. cerebrovascular disease
9. unstable angina or myocardial infarction within 6 months
10. patients with allergic reaction at iloprost

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: placebo; normal saline inhalation group	Drug: normal saline inhalation; When anesthesia induction finishes, change patients' position from supine to lateral position and measure ABGA, VBGA while two lung is ventilated (T0). After 20 minutes of applying one-lung ventilation, measure ABGA and VBGA (T1). Apply normal saline inhalation for control group and measure ABGA at the time of 20 min after normal saline inhalation has finished (T2).
Experimental: iloprost group; iloprost inhalation group	Drug: iloprost inhalation; When anesthesia induction finishes, change patients' position from supine to lateral position and measure ABGA, VBGA while two lung is ventilated (T0). After 20 minutes of applying one-lung ventilation, measure ABGA and VBGA (T1). Apply iloprost inhalation for iloprost group and measure ABGA at the time of 20 min after iloprost inhalation has finished (T2).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Result of arterial blood gas analysis : partial pressure of oxygen(PaO2)	20 minutes after iloprost inhalation (T2)
Result of arterial blood gas analysis : partial pressure of oxygen in the arterial blood(PaO2)/Fraction of inspired oxygen(FiO2) ratio (P/F ratio)	20 minutes after iloprost inhalation (T2)
Result of arterial blood gas analysis : Oxygen saturation in arterial blood(SaO2)	20 minutes after iloprost inhalation (T2)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
deadspace	Dead space ventilation was calculated with Paco2 and end-tidal carbon dioxide (Etco2) according to the Hardman and Aitkenhead equation [1.14 × (Paco2- Etco2)/Paco2 - 0.005].	20 minutes after iloprost inhalation (T2)
intrapulmonary shunt	-Shunt fraction (Qs/Qt) was calculated using the following formula: Qs/Qt = (CcO2-CaO2)/(CcO2-CvO2), (1) -whereby: CaO2 = (PaO2 x 0.0031) + (Hemoglobin x 1.36 x SaO2), (2); CvO2 = (PvO2 x 0.0031) + (Hemoglobin x 1.36 x SvO2), (3); CcO2 = ([FiO2 x (PB - PH2O) - PaCO2/Respiratory quotient] x 0.0031) + (Hemoglobin x 1.36), (4); PB is the barometric pressure (760 mmHg), the PH2O is 47 mmHg	20 minutes after iloprost inhalation (T2)

Collaborators and Investigators

• Sponsor: Yonsei University
• Investigators: Principal Investigator: Young Jun Oh, Severance Hospital

Study record dates

Study Major Dates

• Study Start (Actual): November 2, 2020
• Primary Completion (Actual): September 26, 2025
• Study Completion (Actual): September 26, 2025

Study Registration Dates

• First Submitted: September 17, 2020
• First Submitted That Met QC Criteria: October 4, 2020
• First Posted (Actual): October 12, 2020

Study Record Updates

• Last Update Posted (Actual): December 1, 2025
• Last Update Submitted That Met QC Criteria: November 28, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Respiratory Tract Diseases; Lung Diseases; Respiratory Tract Neoplasms; Thoracic Neoplasms; Lung Neoplasms; Vasodilator Agents; Platelet Aggregation Inhibitors; Iloprost
• Other Study ID Numbers: 4-2020-0722

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No