Related Experiment Video
Updated: Jun 3, 2025

Combining Volumetric Capnography And Barometric Plethysmography To Measure The Lung Structure-function Relationship
Published on: January 8, 2019
Comparison of carbon dioxide control during pressure controlled versus pressure-regulated volume controlled
Rebeca Mozun1, Daphné Chopard2,3, Florian Zapf2
1Department of Intensive Care and Neonatology and Children's Research Center, University of Zurich, University Children's Hospital Zürich, Zurich, Zurich, Switzerland rebeca.mozuntorrico@kispi.uzh.ch.
Insights
This pilot trial tested a digital approach for comparing mechanical ventilation in paediatric intensive care. The study assessed feasibility and carbon dioxide control, paving the way for future digital critical care research.
Area of Science:
- Critical Care Medicine
- Digital Health Technologies
- Paediatric Respiratory Support
Background:
- Paediatric intensive care units (PICUs) have extensive electronic data, yet digital trials for mechanical ventilation are limited.
- Optimal mechanical ventilation strategies in PICUs require further evidence.
- Digital trials offer efficiency benefits and can expand the evidence base for interventions.
Purpose of the Study:
- To test the feasibility of a digital paediatric intensive care unit (PICU) trial.
- To compare two invasive mechanical ventilation modes using carbon dioxide (CO2) control.
- To evaluate adherence and time within target CO2 range in critically ill children.
Main Methods:
- A single-centre, open-label, randomised pilot trial comparing pressure control and pressure-regulated volume control ventilation.
- Inclusion criteria: <18 years, >2kg, arterial line, >60 min ventilation; Exclusion criteria: cardiac shunt, pulmonary hypertension, intracranial hypertension.
- CO2 monitoring via continuous end-tidal/transcutaneous and intermittent blood gas analysis; data collected from electronic health records.
Main Results:
- Primary feasibility outcome: adherence to assigned ventilation mode.
- Primary physiological outcome: proportion of time within target CO2 range (normocarbia).
- Data captured digitally every minute; intention-to-treat analysis planned for 60 enrolled patients.
Conclusions:
- This digital trial design is feasible for assessing mechanical ventilation in critically ill children.
- The study provides a foundation for larger, pragmatic digital trials in paediatric critical care.
- Findings will inform optimal CO2 management strategies during mechanical ventilation in PICU settings.
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, randomised controlled pilot trial with two parallel treatment arms comparing pressure control versus pressure-regulated volume control. Patients are eligible if aged <18 years, weighing >2 kg, have an arterial line and require >60 min of mechanical ventilation during PICU hospitalisation 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 and ≤ 6 kPa). Both primary outcomes are captured digitally every minute from randomisation until censoring (at 48 hours after randomisation, 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 continued for 9 months.
Ethics And Dissemination:
This study received ethical approval from the Cantonal Ethics Commission of Zurich (identification number: 2022-00829). Study results will be disseminated through publication in a peer-reviewed journal and other media like podcasts.
Trial Registration Number:
NCT05843123.
Related Concept Videos
Mechanical Ventilation II: Invasive Ventilation
Negative-Pressure Ventilators
Negative-pressure ventilators create a vacuum around the chest or body to draw air into the lungs, simulating breathing. This method does not require an...
Physiological Control of Respiration
Breathing, a seemingly passive process, is regulated by the respiratory center in the brainstem. This center coordinates the involuntary control of respirations, which means it occurs without conscious effort, ensuring a smooth and uninterrupted pattern.
Regulation of Ventilation
The body maintains ventilation by monitoring levels of carbon dioxide (CO2), oxygen (O2), and hydrogen ion concentration (pH) in the arterial blood. Among these factors, the level of CO2 plays a crucial...
Mechanical Ventilation I: Indication and Settings
Ventilatory Modes
There are three ventilatory modes: full support, partial support, and spontaneous. These are described below.
Full Support Modes
Full support modes include controlled mechanical ventilation, continuous mandatory...
Factors Affecting Pulmonary Ventilation
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...
Respiratory Volumes
Tidal Volume (TV) Tidal volume (TV) is the air inhaled or exhaled in a...

