The RELAX study – REcruitment maneuvers to increase Lung volume After birth in eXtremely preterm infants on invasive mechanical ventilation: a randomized crossover study

The RELAX study – REcruitment maneuvers to increase Lung volume After birth in eXtremely preterm infants on invasive mechanical ventilation: a randomized crossover study - RELAX

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

DRKS

Registry ID

DRKS00038222

Enrollment

Registered

2025-10-24

Start date

2026-03-01

Completion date

Unknown

Last updated

2026-03-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Extreme prematurity with respiratory distress syndrome

Interventions

Group 1: Very preterm infants 0.21 can be randomized. The randomization determines the sequence in which infants receive intervention and control period. Intervention period: During the intervention

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: - Born very preterm (i.e. gestational age at birth 0,21 - Invasively ventilated (i.e. conventional, or high-frequency oscillation) at the beginning of the study

Exclusion criteria

Exclusion criteria: - Severe malformation adversely affecting lung aeration or malformations limiting life expectancy - Inability of the parents to understand the study procedures due to cognitive or linguistic reasons - Intraventricular hemorrhage grade III or IV at the time of study - Infant too unstable to perform data recording as per the treating clinician’s discretion

Design outcomes

Primary

Measure	Time frame
Difference in ?EELI (changes in end-expiratory lung impedance) at the end of the respective two-hour timeframe with vs without recurrent recruitment maneuvers. Delta EELI is recorded using electrical impedance tomography via an EIT belt at mamillary level of the infant. EIT data will be recorded in a breath-by-breath analysis continuously for the entire study period and data will be extracted for analysis of the primary outcome at the beginning of the respective period (i.e. first stable breathing after the last nursing care) and at the end of the respective period (i.e. after two hours). Delta EELI is the difference between beginning and end of the respective study period.	—

Measure

Time frame

Difference in ?EELI (changes in end-expiratory lung impedance) at the end of the respective two-hour timeframe with vs without recurrent recruitment maneuvers. Delta EELI is recorded using electrical impedance tomography via an EIT belt at mamillary level of the infant. EIT data will be recorded in a breath-by-breath analysis continuously for the entire study period and data will be extracted for analysis of the primary outcome at the beginning of the respective period (i.e. first stable breathing after the last nursing care) and at the end of the respective period (i.e. after two hours). Delta EELI is the difference between beginning and end of the respective study period.

—

Secondary

Measure	Time frame
Secondary outcomes include various physiological and clinical parameters (heart rate, oxygen saturation, fraction of inspired oxygen, etc.), as well as global and regional EIT data at pre-defined timepoints: During the intervention period: - during the last five minutes before the first recruitment maneuver (=baseline; also before each of the subsequent recruitment maneuvers) - at the end of each five-minute step of the recruitment maneuver - in the first five minutes after the end of the recruitment maneuver (i.e. after switching back to baseline) - in the last five minutes before the end of the intervention period During the control period (to mirror the intervention period) - during the first five minutes after commencement of the study (=baseline) - in the last five minutes before the full hour and the first five minutes after the full hour plus 20 minutes (corresponding to the measurement at the end of the recruitment maneuver in the intervention group) - in the last five minutes before the end of the control period During each of these timeframes, a 30-second interval of artefact-free tidal ventilation will be collected Also, the following clinical outcomes until 72 hours after birth will be collected as safety outcomes: - Need for additional surfactant application, yes/no - Need for intubation and mechanical ventilation, yes/no - Any novel air leak noted after the intervention, yes/no • pneumothorax requiring drainage, yes/no • pulmonary interstitial emphysema, yes/no - Any new/worsening intraventricular hemorrhage (based on Papile criteria) noted after the intervention, yes/no - Maximum grade of IVH	—

Measure

Time frame

Secondary outcomes include various physiological and clinical parameters (heart rate, oxygen saturation, fraction of inspired oxygen, etc.), as well as global and regional EIT data at pre-defined timepoints: During the intervention period: - during the last five minutes before the first recruitment maneuver (=baseline; also before each of the subsequent recruitment maneuvers) - at the end of each five-minute step of the recruitment maneuver - in the first five minutes after the end of the recruitment maneuver (i.e. after switching back to baseline) - in the last five minutes before the end of the intervention period During the control period (to mirror the intervention period) - during the first five minutes after commencement of the study (=baseline) - in the last five minutes before the full hour and the first five minutes after the full hour plus 20 minutes (corresponding to the measurement at the end of the recruitment maneuver in the intervention group) - in the last five minutes before the end of the control period During each of these timeframes, a 30-second interval of artefact-free tidal ventilation will be collected Also, the following clinical outcomes until 72 hours after birth will be collected as safety outcomes: - Need for additional surfactant application, yes/no - Need for intubation and mechanical ventilation, yes/no - Any novel air leak noted after the intervention, yes/no • pneumothorax requiring drainage, yes/no • pulmonary interstitial emphysema, yes/no - Any new/worsening intraventricular hemorrhage (based on Papile criteria) noted after the intervention, yes/no - Maximum grade of IVH

—

Countries

Germany

Contacts

Public ContactVincent Gaertner

Abteilung für Neonatologie, LMU Klinikum

vincent.gaertner@med.lmu.de+89-4400-57783

Outcome results

None listed

Source: DRKS (via WHO ICTRP) · Data processed: Mar 14, 2026