Effect of a systematic lung-protective protocol for COVID-19 pneumonia requiring invasive ventilation: A single center retrospective study

The benefits of introducing a systematic lung-protective protocol for coronavirus disease 2019 (COVID-19) pneumonia requiring invasive ventilation in the intensive care unit (ICU) are unknown. Herein, we aimed to evaluate the clinical effects of introducing such a protocol in terms of mortality, duration of ventilation, and length of ICU stay. In this single-centre, retrospective, quality comparison study, we identified patients with COVID-19 pneumonia who received invasive ventilation in our ICU between February 2020 and October 2021. We established a systematic lung-protective protocol for the pre-introduction group until March 2021 and the post-introduction group after April 2021. Patients who did not receive invasive ventilation and who underwent veno-venous extracorporeal membrane oxygenation in a referring hospital were excluded. We collected patient characteristics at the time of ICU admission, including age, sex, body mass index (BMI), comorbidities, sequential organ failure assessment (SOFA) score, acute physiology and chronic health evaluation II (APACHE II) score, and Murray score. The study outcomes were ICU mortality, length of ICU stay, and duration of ventilation. The pre-introduction and post-introduction groups included 18 and 50 patients, respectively. No significant differences were observed in sex, BMI, SOFA score, APACHE II score, and Murray score; however, age was lower in the post-introduction group (70 vs. 56, P = 0.003). The introduction of this protocol did not improve ICU mortality. However, it reduced the ICU length of stay (26 days vs. 11 days, P = 0.003) and tended to shorten the duration of ventilation (15 days vs. 10 days, P = 0.06). The introduction of the protocol was associated with a decrease in the length of ICU stay and duration of ventilation; however, it did not change mortality. The application of the protocol could improve the security of medical resources during the COVID-19 pandemic. Further prospective multicentre studies are needed.