Influence of Lung Volume Optimization Maneuver on Cardiac Output and Lung Compliance in Ventilated Children With Congenital Heart Disease Undergoing Surgical Repair (ILOCO-CHD)

Influence of Lung Volume Optimization Maneuver on Cardiac Output and Lung Mechanics in Children With Congenital Heart Disease

The aim of this randomized interventional multi-center clinical trial is to determine whether a standardized lung volume optimization maneuver (LVOM), including PEEP titration, improves outcomes in children undergoing biventricular repair for congenital heart disease (CHD) with cardiopulmonary bypass.

The primary hypothesis is that optimizing end-expiratory lung volume through a standardized PEEP titration maneuver improves cardiac performance and lung function.

Secondary objectives are to evaluate whether this strategy reduces duration of mechanical ventilation, improves hemodynamics and ventilation-perfusion matching, and decreases the need for vasopressor support.

Study Overview

• Status: Not yet recruiting
• Conditions: Children; Cardiac Surgery; Cardiopulmonary Bypass; Congenital Heart Disease; Mechanical Ventilation; Hemodynamic Changes; Lung Mechanics; Positive End-expiratory Pressure (PEEP); Lung Volume; Peep Titration in Lung Protective Ventilation
• Intervention / Treatment: Procedure: Standard Care (in control arm); Procedure: End-expiratory lung volume optimization maneuver with PEEP titration

Detailed Description

Cardiopulmonary bypass is associated with interruption of ventilation, leading to atelectasis, reduced end-expiratory lung volume, and increased pulmonary vascular resistance (PVR), which may impair right ventricular (RV) performance and overall cardiac output.

This study investigates whether a structured LVOM strategy can mitigate these effects by improving lung mechanics and cardiopulmonary interactions.

Specific Aims

Aim 1:

To quantify changes in hemodynamics and lung mechanics induced by LVOM under standardized postoperative (closed-chest) conditions.

Aim 2:

To compare individualized PEEP titration versus standard ventilation in terms of effects on hemodynamics and lung mechanics, while maintaining consistent tidal volume targets across groups.

Hypotheses

LVOM will improve lung mechanics and hemodynamic parameters. No significant between-group differences are expected prior to intervention. After PEEP titration, the intervention group will demonstrate superior cardiopulmonary function at moderate PEEP levels, reflecting the U-shaped relationship between lung volume and pulmonary vascular resistance (PVR).

Scientific Rationale

Cardiopulmonary bypass commonly results in atelectasis and loss of end-expiratory lung volume, contributing to increased PVR and RV afterload, with subsequent reduction in cardiac output.

Adult studies suggest that lung volume optimization through PEEP titration after CPB can improve cardiac index and RV performance. However, prospective pediatric data evaluating the interaction between ventilatory strategy, lung mechanics, and hemodynamics remain limited.

Given the central role of the right ventricle in coupling pulmonary and systemic circulation, optimizing lung volume may reduce RV afterload and improve overall cardiac performance.

Importantly, pulmonary vascular resistance follows a U-shaped relationship with lung volume, with increased resistance at both low (atelectasis) and high (overdistension) lung volumes. Individualized PEEP titration may therefore identify an optimal range that minimizes PVR while preserving hemodynamic stability.

This study addresses a critical gap by systematically evaluating cardiopulmonary interactions under contemporary ventilation strategies in pediatric cardiac surgery.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Phase 2; Phase 1

Contacts and Locations

• Study Contact: Name: Jan C Clausen, MD; Phone Number: 00493045932800; Email: jan.clausen@posteo.de

Study Locations

• Germany
  • Berlin, Germany, 13353
    • German Heart Center of the Charité

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Inclusion Criteria
• congenital heart disease
• surgery with cardiopulmonary bypass

Exclusion Criteria:

• single ventricle physiology
• ECMO/VAD
• <36weeks of gestational age
• chronic lung disease
• Endotracheal tube leak > 15%
• lack of informed consent from parents.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Control; This group receives so called standard of care. This includes relatively low levels of PEEP (5cmH2O in case of planned surgery) and no standardized PEEP titration.	Procedure: Standard Care (in control arm); Patients will receive pressure controlled ventilation with target tidal volume of 6ml/kg and PEEP of 5cmH2O. Driving pressures are limited to 15cmH2O. No LVOM will be applied.
Experimental: Treatment; This group receives an individual lung volume optimization maneuver with PEEP titration. PEEP titration is performed while monitoring lung mechanics and EIT indices of overdistension and collapse and regional tidal volume distribution to optimize end-expiratory lung volume and find final "best PEEP". If possible lung perfusion will be assessed with EIT to evaluate V/Q-matching.	Procedure: End-expiratory lung volume optimization maneuver with PEEP titration; PEEP titration (incremental/decremental) will be performed at the end of surgery to optimize lung volume and find levels of PEEP corresponding to the "best" lung compliance and "best" compromise of overdistension and collapse and "best" homogenization of tidal volume distribution assessed with EIT. PEEP levels will be applied based on individual response of patients' lung mechanics and EIT measures. Tidal volume will be kept constant at 6ml/kg in cases and controls. Driving pressures will be limited to 15cmH2O. Balance of CO2 will be guaranteed by adjusting respiratory rate.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cardiac Index (L/min/BSA)	assessed by using POCUS	perioperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
lung mechanics	lung compliance (ml/cmH2O/kg)	perioperatively
right ventricular performance	TAPSE PAAT Strain	perioperatively
ventilation distribution	EIT	perioperatively
lung perfurision	EIT	perioperatively
dead space fraction	pulmonary dead-space fraction (Vd/Vt)	perioperatively
avDO2	difference in arteriovenous oxygen content	perioperatively

Collaborators and Investigators

• Sponsor: Charite University, Berlin, Germany

Publications and helpful links

General Publications

• "Electrical impedance tomography during open heart surgery and on the cardiac icu is feasible to monitor ventilation in children with congenital heart disease" J.-C. Clausen, M. Emeis, M. Kleine-Brueggeney, M.-Y. Cho, M. Kneyber and O. Miera Intensive Care Medicine - Paediatric and Neonatal 2024 Vol. 2 Issue 1 Pages 19 DOI: 10.1007/s44253-024-00043-4
• Clausen JC, Emeis M, Hollander R, Miera O, Kleine-Brueggeney M, Blokpoel RGT, Garfias-Veitl T, Asendorf T, Vadiunec VV, Photiadis J, Berger F, Kneyber MCJ. Effect of Positive End-Expiratory Pressure on Cardiac Index and Right Ventricular Performance in Ventilated Children Post-Cardiac Surgery. Pediatr Crit Care Med. 2026 Feb 1;27(2):176-186. doi: 10.1097/PCC.0000000000003880. Epub 2025 Dec 19.

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): August 31, 2028
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: March 17, 2026
• First Submitted That Met QC Criteria: March 17, 2026
• First Posted (Actual): March 20, 2026

Study Record Updates

• Last Update Posted (Actual): April 30, 2026
• Last Update Submitted That Met QC Criteria: April 26, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: electrical impedance tomography; end-expiratory lung volume; PEEP titration; cardiopulmonary interactions
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Heart Diseases; Congenital Abnormalities; Cardiovascular Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Heart Defects, Congenital; Health Services Administration; Health Care Quality, Access, and Evaluation; Quality of Health Care; Quality Indicators, Health Care; Standard of Care
• Other Study ID Numbers: EA 2025/06/10

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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