Unilateral Ventilation on Cardiopulmonary Bypass During Cardiac Surgery

Unilateral Ventilation on Cardiopulmonary Bypass During Cardiac Surgery in Patients at Increased Risk for Severe Postoperative Pulmonary Complications

This study investigates if single lung ventilation on cardiopulmonary bypass can mitigate postoperative lung water accumulation determined by lung ultrasound in the ventilated lung as compared to the non-ventilated lung in patients at high-risk for developing severe pulmonary complications after cardiac surgery.

Study Overview

• Status: Not yet recruiting
• Conditions: Cardiopulmonary Bypass; Lung Ultrasound; Electrical Impedance Tomography (EIT); Single-lung Ventilation; Lung Protective Ventilation; Lung Water Assessment; Lung Compliance; Chest X-ray for Clinical Evaluation; Pulmonary Complications in Surgical Patients; Biomarkers of Vascular Endothelial Injury; Oxygenation Indices; High-risk Cardiac Patients
• Intervention / Treatment: Procedure: Ventilated lung; Procedure: Non-ventilated lung.

• Study Type: Interventional
• Enrollment (Estimated): 45
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Martin Dworschak, MD, MBA; Phone Number: 41090 +43-1-40400; Email: martin.dworschak@meduniwien.ac.at
• Study Contact Backup: Name: Edda M. Tschernko, MD, MBA; Phone Number: 41060 +43-1-40400; Email: edda.tschernko@meduniwien.ac.at

Study Locations

• Austria
  • State of Vienna
    • Vienna, State of Vienna, Austria, 1090
      • General Hospital Vienna
      • Contact: Martin Dworschak, MD, MBA; Phone Number: 41090 +43-1-40400; Email: martin.dworschak@meduniwien.ac.at
      • Contact: Edda M. Tschernko, MD, MBA; Phone Number: 41060 +43-1-40400; Email: edda.tschernko@meduniwien.ac.at
      • Principal Investigator: Martin Dworschak, MD, MBA
      • Sub-Investigator: Edda M. Tschernko, MD, MBA
      • Sub-Investigator: Keso Skhirtladze-Dworschak, MD
      • Sub-Investigator: Florentina Zingher, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients at increased risk for postoperative pulmonary complications
• Major elective cardiac surgery
• Prolonged duration of cardiopulmonary bypass
• Patients older than 65 years of age
• Informed consent

Exclusion Criteria:

• Emergency
• Urgent procedures
• Patients with implanted pacemakers
• Patients with internal cardioverter/defibrillators
• Decompensated cardiac disease
• Pulmonary disease
• Recent pneumonia
• Need for temporary perioperative mechanical support
• Patients not willing to participate
• Treatment with inhaled nitric oxide

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Active Comparator: Risk group; Lung ventilated during cardiopulmonary bypass using single-lung ventilation via double-lumen tube.

Procedure: Ventilated lung; This lung will be ventilated during cardiopulmonary bypass using volume-controlled ventilation with a tidal volume of 3 mL/kg ideal body weight, a PEEP of 5 cmH2O, a respiratory rate of 10/min, and a fraction of inspired oxygen of 30%.; Procedure: Non-ventilated lung.; The contralateral lung will not be ventilated during cardiopulmonary bypass and will be allowed to collapse.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Lung aeration score of both lungs.	The aeration score of each lung is the sum of the aeration scores determined in each of six lung quadrants in each lung, which can range from 0 (normal ventilation) to 3 (atelectasis/consolidation).	Lung ultrasound investigations will be performed at baseline, i.e., before surgery, on the day of surgery, and on day 1 and 2 after surgery in the intensive care unit.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Radiologic assessment of Kerley B lines as indicators of lung edema.	Number of Kerley B lines in both lungs determined by chest x-ray where stage 1 (no Kerley B lines) reflects best outcome, stage 2 (Kerley B lines become visible) indicates interstitial edema, and stage 3 (increased number of Kerley B lines also in non-dependent areas and partially obscured in dependent parts of the lung) are a sign of alveolar edema.	Performed on the day of surgery and on day 1 and 2 after surgery on the intensive care unit.
Presence of pleural effusion in chest x-ray.	Severity assessment will be semi-quantitative with 0 = no effusion, 1 = small effusion (with blunting of the basal lung segments and the costophrenic angle), 2 = moderate effusion (fluid extents to the mid-hemithorax creating a "meniscus sign"), and 3 = massive effusion (the whole lung appears opaque with displacement of the heart to the contralateral side if located unilaterally).	Performed on the day of surgery and on day 1 and 2 after surgery on the intensive care unit.
Determination of the Global Inhomogeneity (GI) index in both lungs separately by thoracic Electrical Impedance Tomography (EIT).	Global inhomogeneity is calculated as the sum of the absolute differences between the median value of tidal variation and every single pixel value, divided by the sum of all impedance values, to normalize the calculated values. A GI index closer to 0 represents highly homogeneous (even) ventilation. Higher values (i.e., > 0.5) indicate that some parts of the lung are over-distended while others are poorly aerated or collapsed (atelectasis).	On the day of surgery and on day 1 and 2 after surgery in the intensive care unit.
Worst oxygenation (Horowitz) index measured per day during routine blood gas checks.	The Horowitz index (HI) is calculated by diving arterial oxygen partial pressure determined in the blood gas by the fraction of inspired oxygen. It will be assessed after each blood gas check and the lowest HI during one day will be entered for further statistical analysis. The degree of impaired lung function will be determined as follows: HI > 300 mmHg (healthy lung function), HI between 201-300 mmHg (mild lung injury), HI between 101-200 mmHg (moderately severely impaired lung function), and HI < 100 mmHg (severe lung injury, ARDS).	Assessed on the day of surgery and on day 1 and 2 after surgery.
Static lung compliance determined in each lung separately.	Static lung compliance of the ventilated and the non-ventilated lung will be determined twice for each patient. Static compliance in healthy adults ranges between 60 and 100 mL/cm H₂O. Values below 50 mL/cm H₂O would be considered abnormally low.	On the day of surgery in the operating room before and after cardiac surgery on cardiopulmonary bypass when the patient is still ventilated via double lumen tube.
Amount of released immune modulators.	Serum levels for HSP70, MMP-8, MMP-9, TIMP-1, and Lipocalin-2 will be determined in patients' blood samples, with normal values ranging from 0.2-3 ng/mL for HSP70, 0.3-1.2 ng/mL for MMP-8, 14-100 ng/mL for MMP-9, 80-150 ng/mL for TIMP-1, and 20-130 ng/mL for Lipocalin-2, respectively.	Determined on the day of surgery as well as on day 1, 2, 3, and 4 after surgery.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Length of ICU and hospital stay.	The duration from transfer to the intensive care unit until discharge to a step-down unit and the duration of hospitalization of the patient will be determined in days.	These variables will be censored at study completion, on average 30 days.
In-hospital mortality.	It will be recorded if the patient has been discharged from the hospital alive.	In-hospital mortality will be censored at study completion, on average 30 days.
Duration on respiratory support via endotracheal tube.	The hours between arrival of the intubated patient on the intensive care unit until extubation will be determined.	The time until extubation will be censored at study completion, on average 30 days.
Postoperative complications.	Any complication that poses a risk for the patient occurring during the hospital stay and having been documented in the patient's file will be retrieved by carefully reviewing the files and recorded.	All complications will be censored at study completion, on average 30 days.

Collaborators and Investigators

• Sponsor: Medical University of Vienna
• Investigators: Principal Investigator: Martin Dworschak, MD, MBA, Medical University of Vienna

Study record dates

Study Major Dates

• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): July 31, 2029

Study Registration Dates

• First Submitted: April 4, 2026
• First Submitted That Met QC Criteria: May 24, 2026
• First Posted (Actual): May 29, 2026

Study Record Updates

• Last Update Posted (Actual): May 29, 2026
• Last Update Submitted That Met QC Criteria: May 24, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: EK Nr: 1250/2021

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The primary reason for not sharing IPD is the protection of patient privacy.

Drug and device information, study documents

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