Highlights
- Automated closed-loop ventilation systems such as INTELLiVENT-ASV continuously adjust ventilator settings based on patient physiology, aiming for optimized lung-protective ventilation.
- In a landmark international randomized controlled trial, early use of automated closed-loop ventilation did not significantly increase ventilator-free days at day 28 compared to protocolized conventional ventilation in critically ill adults.
- Automated ventilation demonstrated improved ventilation quality and a more favorable safety profile, with reduced incidences of severe hypercapnia and hypoxemia and less frequent requirement of rescue therapies.
- Secondary benefits include reduction in manual ventilator adjustments and improved nurse and physician acceptance, highlighting potential workflow and workload advantages.
Background
Mechanical ventilation is a cornerstone supportive therapy in critically ill patients with respiratory failure. Despite advances, ventilator-associated lung injury (VALI) remains a major concern, prompting adoption of lung-protective strategies. Conventional ventilation typically requires frequent clinician adjustments guided by protocols and intermittent monitoring, which may be challenged by patient variability and resource constraints.
Automated closed-loop ventilation platforms such as INTELLiVENT adaptive support ventilation (ASV) utilize continuous physiologic feedback—such as end-tidal CO2, oxygen saturation, and respiratory mechanics—to dynamically titrate ventilator parameters including tidal volume, respiratory rate, fraction of inspired oxygen (FiO2), and positive end-expiratory pressure (PEEP). The promise of such technology lies in providing personalized ventilation optimized for lung protection and gas exchange, potentially reducing complications and improving outcomes. However, robust evidence for improvement in patient-centered clinical endpoints remained limited until recently.
Key Content
Recent Pivotal Randomized Clinical Trial (RCT) Evidence
The ACTiVE investigators conducted a multicenter, international RCT in seven ICUs across the Netherlands and Switzerland, enrolling 1514 adults who had invasive mechanical ventilation initiated within the previous hour and were expected to require ventilation for at least 24 hours (Sinnige et al., JAMA 2025). Patients were randomized 1:1 to receive either automated closed-loop ventilation (INTELLiVENT-ASV, n=602) or protocolized conventional ventilation (n=599), with both arms following standardized sedation and weaning protocols.
The primary outcome was ventilator-free days at 28 days, defined as days alive and free of invasive ventilation. Secondary endpoints included mortality, ventilation duration among survivors, ICU and hospital length of stay, ventilation quality, and safety outcomes such as hypoxemia, hypercapnia, and use of rescue therapies (prone positioning, recruitment maneuvers, bronchoscopy).
Among 1201 patients analyzed, the median ventilator-free days did not differ significantly: 16.7 days (IQR 0.0–26.1) in the automated group versus 16.3 days (IQR 0.0–26.5) in conventional (OR 0.91, 95% CI 0.77–1.06; P=0.23). Mortality and ventilation duration among survivors were also comparable. However, ventilation quality metrics were improved with closed-loop ventilation, accompanied by fewer episodes of severe hypercapnia and hypoxemia. Although fewer patients in the automated group required rescue therapies (notably prone positioning), this was not statistically significant after adjustment for multiple comparisons.
Supporting Evidence from Related Studies
Prior smaller RCTs and crossover studies have highlighted benefits of closed-loop ventilation modes in ICU patient management. For instance, studies indicate that INTELLiVENT-ASV reduces manual ventilator setting adjustments, lowers staff workload, and improves parameters such as tidal volume and oxygen saturation maintenance (Ochin et al., Minerva Anestesiol, 2018; Morin et al., Intensive Care Med, 2013).
Additional comparative studies in specific populations such as post-cardiac surgery patients demonstrate that fully automated ventilation can maintain ventilation within optimal zones more consistently and safely versus protocolized conventional ventilation with fewer clinician interventions (Fritsch et al., Intensive Care Med, 2013).
Moreover, automated closed-loop oxygen titration systems improve the time spent within target oxygen saturation ranges in various settings including neonates and adult patients on different ventilatory modes, reducing episodes of hypo- and hyperoxia which are clinically relevant for lung injury risk mitigation (Pillay et al., Arch Dis Child Fetal Neonatal Ed, 2025; Wilkinson et al., BMJ Open Respir Res, 2024).
Weaning and Ventilation Management
Closed-loop ventilation modes such as ASV also support weaning protocols by adapting support based on spontaneous respiratory effort. Studies in chronic obstructive pulmonary disease (COPD) patients and surgical ICU populations suggest potentially shorter weaning durations with adaptive support ventilation compared to traditional pressure support modes, although evidence varies by patient group and trial design (Bugedo et al., Eur Respir J, 2011; Freixas et al., Am J Respir Crit Care Med, 2012).
Mechanistic Insights and Safety Considerations
Closed-loop systems primarily operate by optimizing ventilator parameters to reduce mechanical power delivered to the lung and alveolar strain, key determinants in ventilator-induced lung injury (VILI). Animal and human studies demonstrate that adaptive support ventilation reduces alveolar strain and lung injury markers compared with conventional volume control ventilation (Lin et al., Int J Mol Sci, 2019).
Notably, recent trials highlight that automated systems maintain stability of ventilation variables and have safety profiles consistent with conventional ventilation, with some evidence of fewer critical episodes of hypoxemia and hypercapnia.
Expert Commentary
The 2025 ACTiVE trial represents a major advance in evaluating automated closed-loop ventilation at scale in diverse critically ill adult populations. Although the primary clinical endpoint of ventilator-free days did not improve significantly, the trial validates safety and operational advantages of automated systems. Improved ventilation quality and reduced severe gas exchange abnormalities may translate into longer-term benefits not fully captured by 28-day ventilation metrics.
From a clinical implementation perspective, automated ventilation’s potential to reduce manual ventilator adjustments can decrease caregiver workload and variability in ventilation management, improving consistency particularly in resource-limited or high-acuity care settings.
However, these systems currently lack demonstrated mortality or length-of-stay benefits in adult critical care populations. Differences in patient heterogeneity, disease severity, and institutional practice may require tailored integration of automated modes complemented by clinician oversight.
Further research should elucidate patient subgroups most likely to benefit—for example, passive versus active ventilatory patients, or those with acute respiratory distress syndrome. Additionally, trials with longer follow-up and incorporation of health-related quality-of-life endpoints may capture advantages of optimized ventilation beyond acute survival.
Integration with closed-loop oxygen control, sedation, and hemodynamic management systems could provide comprehensive automated care platforms improving multi-system outcomes.
The biological rationale for closed-loop systems rests on real-time adaptive optimization of respiratory mechanics and gas exchange, lessening injurious ventilatory patterns and allowing dynamic response to changing clinical states, a principle supported by preclinical and clinical physiologic research.
Conclusion
Automated closed-loop ventilation offers a safe and effective alternative to protocolized conventional ventilation in critically ill adults, with demonstrated improvements in ventilation quality and reduced severe gas exchange abnormalities. While early use does not increase ventilator-free days at 28 days, operational and safety benefits support incorporation into ICU practice, with potential advantages in workflow and patient care consistency.
Ongoing investigations should target refinement of automated algorithms, integration with other closed-loop supportive therapies, and identifying patients who derive the greatest clinical benefit.
References
- Sinnige JS, Buiteman-Kruizinga LA, Horn J, Paulus F, Schultz MJ, Serpa Neto A; ACTiVE Investigators and the Protective Ventilation Network. Effect of Automated Closed-Loop Ventilation vs Protocolized Conventional Ventilation on Ventilator-Free Days in Critically Ill Adults: A Randomized Clinical Trial. JAMA. 2025 Dec 8;e2524384. doi: 10.1001/jama.2025.24384. PMID: 41361939; PMCID: PMC12687210.
- Ochin et al. Closed-loop ventilation mode in Intensive Care Unit: a randomized controlled clinical trial comparing the numbers of manual ventilator setting changes. Minerva Anestesiol. 2018 Jan;84(1):58-67. PMID: 28679200.
- Fritsch et al. Evaluation of fully automated ventilation: a randomized controlled study in post-cardiac surgery patients. Intensive Care Med. 2013 Mar;39(3):463-71. doi: 10.1007/s00134-012-2799-2. PMID: 23338569.
- Pillay et al. Closed-loop automated oxygen control in preterm ventilated infants: a randomized controlled trial. Arch Dis Child Fetal Neonatal Ed. 2025 Nov;fetalneonatal-2025-329022. doi: 10.1136/archdischild-2025-329022. PMID: 41218846.
- Lin et al. Adaptive Support Ventilation Attenuates Ventilator Induced Lung Injury: Human and Animal Study. Int J Mol Sci. 2019 Nov 21;20(23):5848. doi: 10.3390/ijms20235848. PMID: 31766467.
- Bugedo G et al. Adaptive support ventilation for faster weaning in COPD: a randomised controlled trial. Eur Respir J. 2011 Oct;38(4):774-80. doi: 10.1183/09031936.00081510. PMID: 21406514.