The level of partial pressure of carbon dioxide affects respiratory effort in COVID-19 patients undergoing pressure support ventilation with extracorporeal membrane oxygenation.

"Declarations Ethics approval and consent to participateThe study was performed based on the Declaration of Helsinki. All experiments were performed in accordance with relevant guidelines and regulations. The ethics committee of Peking Union Medical College Hospital approved this study (Ethics certificate number: K23C1385). Written informed consent was provided from the patients and from the next of kin of all enrolled patients. Consent for publicationNot applicable. Competing interestsThe authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article. Competing interests The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article."

"Funding This work was supported by the National High-Level Hospital Clinical Research Funding(2022-PUMCH-A-216), Central University Education and Teaching Reform Special Funding of Peking Union Medical College in 2023(2023zlgl022), the National High-Level Hospital Clinical Research Funding (2022-PUMCH-B-115)."