Flow Controlled Ventilation in Cardiac Surgery

Flow Controlled Ventilation Versus Pressure Controlled Ventilation in Cardiac Surgery After Cardiopulmonary Bypass Without Ventilation - a Prospective, Randomized Clinical Study

This trial investigates effects of individualized (by compliance guided pressure settings) flow-controlled ventilation compared to best clinical practice pressure controlled ventilation in cardiac surgery requiring cardiopulmonary bypass.

Study Overview

• Status: Completed
• Conditions: Positive-Pressure Respiration; Respiration; Artificial
• Intervention / Treatment: Device: Evone; Device: Primus

Detailed Description

The aim of the study is to investigate flow-controlled ventilation (FCV) during cardiac surgery requiring cardiopulmonary bypass. Previous preclinical trials have already shown improved oxygenation and CO2 removal within a significantly reduced respiratory minute volume as an expression of more efficient gas exchange with FCV compared to volume controlled ventilation (VCV). Preliminary data of our own animal study comparing individualized FCV by compliance guided pressure settings with state-of-the-art low tidal volume pressure controlled ventilation (PCV) confirmed previous findings with a significantly improved oxygenation by 20% while reducing respiratory minute volume. We therefore assume that FCV may be a more lung protective ventilation method.

Open heart surgery requires bridging of the heart and lung function with a cardiopulmonary bypass (CPB) performed by a heart-lung machine. During this time the lung is most frequently not ventilated at all and lies collapsed in the chest for several hours. After weaning from CPB, the lungs must be recruited and ensure sufficient gas exchange of the blood. Not surprisingly, the incidence of postoperative pulmonary complications (PPC) at 20-30% is comparatively high after cardiac surgery and is the leading cause of perioperative mortality. Based on previous trials we expect improved oxygenation and thus arterial partial pressure of oxygen (pO2) is the main primary outcome parameter of this study. Furthermore, we expect improved recruitment of lung tissue due to controlled expiratory flow in FCV without the need of recruitment maneuvers, which may cause deleterious effects on lung tissue. Thus, lung tissue aeration assessed by Hounsfield units analyses of a postoperative computed tomography will be a secondary outcome parameter.

• Study Type: Interventional
• Enrollment (Actual): 54
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Austria
  • Tyrol
    • Innsbruck, Tyrol, Austria, 6020
      • Medical University Innsbruck

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 99 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Male and female subjects >18 years
• Body weight >40 kg
• Elective cardiac surgery with CPB and without ventilation during CPB
• American Society of Anaesthesiologists (ASA) risc classification I-IV
• Written informed consent

Exclusion Criteria:

• Emergency surgery
• Female subjects known to be pregnant
• Known participation in another interventional clinical trial
• High risk cardiac surgery such as double valve surgery, re-cardiac surgery, intraoperative cardiac arrest or pre-existing high grade cardiomyopathy (ejection fraction <30%)
• Closing operation field without chest closure due to hemodynamic instability
• Acute endocarditis under antibiotic treatment
• Minimal invasive valve surgery via thoracotomy (MIC)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: FCV; Artificial ventilation will be performed with individualized flow-controlled ventilation (Evone, Ventinova Medical B.V., Eindhoven, the Netherlands) during cardiac surgery until admission to postoperative ICU. Individualisation will be established by compliance guided end-expiratory and peak pressure setting, flow setting will be adjusted to secure normocapnia and I:E Ratio set to 1:1.	Device: Evone; Airway ventilation device
Active Comparator: PCV; Artificial ventilation will be performed with low tidal volume pressure-controlled ventilation (Primus, Dräger, Lübeck, Germany) during cardiac surgery until admission to postoperative ICU. Peak pressure will be set to achieve a tidal volume of 7ml/kg predicted body weight at a compliance titrated positive end-expiratory pressure. Respiratory rate will be set to maintain normocapnia and I:E ratio set to 1:1.5 except extension of expiration is necessary in order to avoid air trapping.	Device: Primus; Airway ventilation device

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Horowitz Index	arterial partial pressure of Oxygen (paO2) / fraction of inspired Oxygen (FiO2)	15 minutes after chest closure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
lung tissue aeration	Lung tissue aeration assessed by Hounsfield units analysis of computed tomography	immediately postoperative

Collaborators and Investigators

• Sponsor: Medical University Innsbruck
• Investigators: Principal Investigator: Judith Martini, MD, Medical University Innsbruck, Dept. of Anaesthesiology

Publications and helpful links

General Publications

• Schmidt J, Wenzel C, Mahn M, Spassov S, Cristina Schmitz H, Borgmann S, Lin Z, Haberstroh J, Meckel S, Eiden S, Wirth S, Buerkle H, Schumann S. Improved lung recruitment and oxygenation during mandatory ventilation with a new expiratory ventilation assistance device: A controlled interventional trial in healthy pigs. Eur J Anaesthesiol. 2018 Oct;35(10):736-744. doi: 10.1097/EJA.0000000000000819.

Study record dates

Study Major Dates

• Study Start (Actual): March 6, 2020
• Primary Completion (Actual): March 2, 2021
• Study Completion (Actual): March 2, 2021

Study Registration Dates

• First Submitted: March 10, 2020
• First Submitted That Met QC Criteria: March 10, 2020
• First Posted (Actual): March 13, 2020

Study Record Updates

• Last Update Posted (Actual): March 23, 2021
• Last Update Submitted That Met QC Criteria: March 22, 2021
• Last Verified: March 1, 2021

More Information

Terms related to this study

• Keywords: cardiac surgery; pressure controlled ventilation; flow controlled ventilation
• Other Study ID Numbers: 1211/2019

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