Introduction: Digital trials are a promising strategy to increase the evidence base for common interventions and may convey considerable efficiency benefits in trial conduct. Although paediatric intensive care units (PICUs) are rich in routine electronic data, highly pragmatic digital trials in this field remain scarce. There are unmet evidence needs for optimal mechanical ventilation modes in paediatric intensive care. We aim to test the feasibility of a digital PICU trial comparing two modes of invasive mechanical ventilation using carbon dioxide (CO2) control as the outcome measure. Methods and analysis: Single-centre, open-labelled, randomized controlled pilot trial with two parallel treatment arms comparing pressure control (PC) vs pressure-regulated volume control (PRVC). Patients are eligible if aged <18 years, weighing >2 kg, have an arterial line, and require >60 minutes of mechanical ventilation during PICU hospitalization at the University Children's Hospital Zurich. Exclusion criteria include cardiac shunt lesions, pulmonary hypertension under treatment, and intracranial hypertension. CO2 is measured using three methods: end-tidal (continuous), transcutaneous (continuous), and blood gas analyses (intermittent). Baseline, intervention, and outcome data are collected electronically from the patients' routine electronic health records. The primary feasibility outcome is adherence to the assigned ventilation mode, while the primary physiological outcome is the proportion of time spent within the target range of CO2 (end-tidal, normocarbia defined as CO2 ≥ 4.5, ≤ 6 kPa). Both outcomes are captured digitally every minute from randomization until censoring (48 hours after randomization, extubation, discharge, or death, whichever comes first). Analysis will occur on an intention-to-treat basis. We aim to enrol 60 patients in total. Recruitment started in January 2024 and is planned to continue for 6 months. Ethics and dissemination: This study received ethical approval (BASEC 2022-00829). Study results will be disseminated through publication in a peer-reviewed journal and other media like podcasts. Trial registration number: NCT058431

The authors have declared no competing interest.

NCT05843123

Rebeca Mozun and this study is funded by the Children's Research Center of the University Children's Hospital Zurich (FZK Nachwuchsfoerderung grant). Luregn Schlapbach is supported by the grant NDS-2021-911 (SwissPedHealth) from the Swiss Personalized Health Network (SPHN) and the Strategic Focal Area Personalized Health and Related Technologies (PHRT) of the ETH Domain (Swiss Federal Institutes of Technology), by the NOMIS foundation, the Medical Research Future Fund (MRFF), the National Institutes of Health (NIH), the Foundation Sana, the Stiftung fuer naturwissenschaftliche Forschung. Kristen Gibbons is funded by an NHMRC Investigator Grant. Daphne Chopard is funded thorough the grant 2021-911 from the of the Strategic Focal Area Personalized Health and Related Technologies (PHRT) of the ETH Domain (Swiss Federal Institutes of Technology). The funding sources have no involvement in study design, analysis or interpretation of results.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

This study has received ethical approval (ethics committee of the canton of Zurich, BASEC 2022-00829).

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

The research team will have access to the dataset of this study. Anonymized data could be available upon reasonable request after approval from the research committee and sponsoring institution.