Closed-loop oxygen usage during invasive mechanical ventilation of pediatric patients (CLOUDIMPP): a randomized controlled cross-over study

Abstract

Background: The aim of this study is the evaluation of a closed-loop oxygen control system in pediatric patients undergoing invasive mechanical ventilation (IMV).

Methods: Cross-over, multicenter, randomized, single-blind clinical trial. Patients between the ages of 1 month and 18 years who were undergoing IMV therapy for acute hypoxemic respiratory failure (AHRF) were assigned at random to either begin with a 2-hour period of closed-loop oxygen control or manual oxygen titrations. By using closed-loop oxygen control, the patients' SpO₂ levels were maintained within a predetermined target range by the automated adjustment of the FiO₂. During the manual oxygen titration phase of the trial, healthcare professionals at the bedside made manual changes to the FiO₂, while maintaining the same target range for SpO₂. Following either period, the patient transitioned to the alternative therapy. The outcomes were the percentage of time spent in predefined SpO₂ ranges ±2% (primary), FiO₂, total oxygen use, and the number of manual adjustments.

Findings: The median age of included 33 patients was 17 (13-55.5) months. In contrast to manual oxygen titrations, patients spent a greater proportion of time within a predefined optimal SpO₂ range when the closed-loop oxygen controller was enabled (95.7% [IQR 92.1-100%] vs. 65.6% [IQR 41.6-82.5%]), mean difference 33.4% [95%-CI 24.5-42%]; P < 0.001). Median FiO₂ was lower (32.1% [IQR 23.9-54.1%] vs. 40.6% [IQR 31.1-62.8%]; P < 0.001) similar to total oxygen use (19.8 L/h [IQR 4.6-64.8] vs. 39.4 L/h [IQR 16.8-79]; P < 0.001); however, median SpO₂/FiO₂ was higher (329.4 [IQR 180-411.1] vs. 246.7 [IQR 151.1-320.5]; P < 0.001) with closed-loop oxygen control. With closed-loop oxygen control, the median number of manual adjustments reduced (0.0 [IQR 0.0-0.0] vs. 1 [IQR 0.0-2.2]; P < 0.001).

Conclusion: Closed-loop oxygen control enhances oxygen therapy in pediatric patients undergoing IMV for AHRF, potentially leading to more efficient utilization of oxygen. This technology also decreases the necessity for manual adjustments, which could reduce the workloads of healthcare providers.

Clinical trial registration: This research has been submitted to ClinicalTrials.gov (NCT05714527).

Keywords: automation; closed-loop; hypoxemia; intensive care; invasive mechanical ventilation; oxygen controller; oxygen therapy; pediatrics.

Figure 1

Trial profile.

Figure 2

Time spent in optimal, suboptimal and unacceptable SpO₂ ranges.

Figure 3

Effect of closed-loop control on time spent in optimum SpO₂ zone, total oxygen use, manual FiO₂ adjustments and SpO₂/FiO_2. The left panels collectively illustrate the effectiveness of the closed-loop system compared to manual adjustments across several parameters. The time spent in the optimum SpO₂ zone is generally higher and more consistent with the closed-loop system, as indicated by the individual data points and box plots. Additionally, total oxygen use is lower with the closed-loop system, reflecting its efficiency in oxygen utilization. The need for manual FiO₂ adjustments is significantly reduced when using the closed-loop system, highlighting its automation advantage. Furthermore, the SpO₂/FiO₂ ratio is higher and more stable with the closed-loop system, demonstrating better oxygenation efficiency. These findings suggest that the closed-loop system provides superior control and management of oxygen levels in patients. The right panels depict the differences between the closed-loop and manual methods for each parameter through density plots and scatter plots. For time spent in the optimum SpO₂ zone, the closed-loop system shows a higher and more consistent distribution compared to manual adjustments. The total oxygen use is clearly lower with the closed-loop system, indicating its greater efficiency. The need for manual FiO₂ adjustments is considerably fewer with the closed-loop system, as shown by the shift toward fewer adjustments. Lastly, the SpO₂/FiO₂ ratio is maintained at a higher level with the closed-loop system, reflecting better overall oxygenation. These visualizations confirm the advantages of the closed-loop system in providing efficient and effective oxygen management.