Abstract
Introduction Hypoxaemia and hyperoxaemia may occur after surgery, with related complications. This multicentre randomised trial evaluated the impact of automated closed-loop oxygen administration after high-risk abdominal or thoracic surgeries in terms of optimising the oxygen saturation measured by pulse oximetry time within target range.
Methods After extubation, patients with an intermediate to high risk of post-operative pulmonary complications were randomised to “standard” or “automated” closed-loop oxygen administration. The primary outcome was the percentage of time within the oxygenation range, during a 3-day frame. The secondary outcomes were the time with hypoxaemia and hyperoxaemia under oxygen.
Results Among the 200 patients, time within range was higher in the automated group, both initially (≤3 h; 91.4±13.7% versus 40.2±35.1% of time, difference +51.0% (95% CI −42.8–59.2%); p<0.0001) and during the 3-day period (94.0±11.3% versus 62.1±23.3% of time, difference +31.9% (95% CI 26.3–37.4%); p<0.0001). Periods of hypoxaemia were reduced in the automated group (≤3 days; 32.6±57.8 min (1.2±1.9%) versus 370.5±594.3 min (5.0±11.2%), difference −10.2% (95% CI −13.9–−6.6%); p<0.0001), as well as hyperoxaemia under oxygen (≤3 days; 5.1±10.9 min (4.8±11.2%) versus 177.9±277.2 min (27.0±23.8%), difference −22.0% (95% CI −27.6–−16.4%); p<0.0001). Kaplan–Meier analysis depicted a significant difference in terms of hypoxaemia (p=0.01) and severe hypoxaemia (p=0.0003) occurrence between groups in favour of the automated group. 25 patients experienced hypoxaemia for >10% of the entire monitoring time during the 3 days within the standard group, as compared to the automated group (p<0.0001).
Conclusion Automated closed-loop oxygen administration promotes greater time within the oxygenation target, as compared to standard manual administration, thus reducing the occurrence of hypoxaemia and hyperoxaemia.
Abstract
Following high-risk surgery, automated closed-loop oxygen administration promotes a higher time within range as compared to standard manual administration https://bit.ly/2ZPHT5Y
Footnotes
This article has supplementary material available from erj.ersjournals.com
This study is registered at Clinicaltrials.gov with identifier NCT02546830.
Data availability: Study protocol, SAP, informed consent, and study report will be available to anyone who wishes to access the data on individual demand to the promoter.
Author contributors: E. L'Her and F. Lellouche designed this study, drafted the manuscript of the protocol and critically revised the manuscript. E. L'Her, S. Jaber, D. Verzilli, C. Jacob, B. Huiban, E. Futier, T. Kerforne, V. Pateau, P-A. Bouchard, M. Consigny and F. Lellouche participated in the conduct of the study. M. Consigny and E. Nowak participated in the protocol methodological assessment and statistical plan. All authors read and approved the final manuscript.
Ethics approval: The institutional review board of the University Hospital of Brest (France) approved the trial for all French centres (IDRCB RB14-060). The institutional review board from the Québec Heart and Lung Institute (Canada) approved the trial for their own centre. Any protocol modification will be submitted for review and approval by the ethics committee. The FreeO2 Post-Op study is conducted in accordance with the declaration of Helsinki and was registered on September 11, 2015 at http://www.clinicaltrials.gov with trial identification number NCT02546830. First patient inclusion was performed on January 14, 2016.
Conflict of interest: E. L'Her reports other from Oxynov, during the conduct of the study; personal fees from Smiths Medical, personal fees and other from GE Healthcare, grants and personal fees from Sedana Medical, outside the submitted work. In addition, E. L'Her has a patent Method and device for delivering oxygen licensed to Oxynov.
Conflict of interest: S. Jaber reports personal fees from Drager, Fisher-Paykel, Baxter, Fresenius-Xenios and Medtronic, during the conduct of the study.
Conflict of interest: D. Verzilli has nothing to disclose.
Conflict of interest: C. Jacob has nothing to disclose.
Conflict of interest: B. Huiban has nothing to disclose.
Conflict of interest: E. Futier reports consulting fees from Drager Medical, GE Healthcare, Orion Pharma and Edwards Lifesciences, lecture fees from Fresenius Kabi and Getinge, and non-financial support from Fisher and Paykel Healthcare, during the conduct of the study.
Conflict of interest: T. Kerforne has nothing to disclose.
Conflict of interest: V. Pateau reports other from OxyNov, during the conduct of the study.
Conflict of interest: P-A. Bouchard has nothing to disclose.
Conflict of interest: M. Consigny has nothing to disclose.
Conflict of interest: F. Lellouche reports other from Oxynov, during the conduct of the study.
Support statement: This trial was funded by the French Ministry of Health obtained in 2014 from a regional hospital clinical research programme (Programme Hospitalier de Recherche Clinique Interrégional HUGO 2012-199). The sponsors had no role in the study design and conduct; the collection, management, analysis and interpretation of the data; or the preparation and approval of the manuscript. Funding information for this article has been deposited with the Crossref Funder Registry.
- Received January 30, 2020.
- Accepted July 17, 2020.
- Copyright ©ERS 2021
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