Dead space estimates may not be independently associated with 28-day mortality in COVID-19 ARDS


    Research output: Contribution to journalArticleAcademicpeer-review


    Background: Estimates for dead space ventilation have been shown to be independently associated with an increased risk of mortality in the acute respiratory distress syndrome and small case series of COVID-19-related ARDS. Methods: Secondary analysis from the PRoVENT-COVID study. The PRoVENT-COVID is a national, multicenter, retrospective observational study done at 22 intensive care units in the Netherlands. Consecutive patients aged at least 18 years were eligible for participation if they had received invasive ventilation for COVID-19 at a participating ICU during the first month of the national outbreak in the Netherlands. The aim was to quantify the dynamics and determine the prognostic value of surrogate markers of wasted ventilation in patients with COVID-19-related ARDS. Results: A total of 927 consecutive patients admitted with COVID-19-related ARDS were included in this study. Estimations of wasted ventilation such as the estimated dead space fraction (by Harris–Benedict and direct method) and ventilatory ratio were significantly higher in non-survivors than survivors at baseline and during the following days of mechanical ventilation (p < 0.001). The end-tidal-to-arterial PCO2 ratio was lower in non-survivors than in survivors (p < 0.001). As ARDS severity increased, mortality increased with successive tertiles of dead space fraction by Harris–Benedict and by direct estimation, and with an increase in the VR. The same trend was observed with decreased levels in the tertiles for the end-tidal-to-arterial PCO2 ratio. After adjustment for a base risk model that included chronic comorbidities and ventilation- and oxygenation-parameters, none of the dead space estimates measured at the start of ventilation or the following days were significantly associated with 28-day mortality. Conclusions: There is significant impairment of ventilation in the early course of COVID-19-related ARDS but quantification of this impairment does not add prognostic information when added to a baseline risk model. Trial registration: ISRCTN04346342. Registered 15 April 2020. Retrospectively registered.
    Original languageEnglish
    Article number171
    Number of pages13
    JournalCritical Care
    Issue number1
    Early online date17 May 2021
    Publication statusPublished - 1 Dec 2021


    • adults
    • biomarkers
    • covid-19
    • female
    • male
    • intensive care units
    • prognosis
    • patient acuity
    • roc curve
    • artificial respiration
    • dead space
    • respiratory distress syndrome
    • etiology
    • respiratory function tests
    • respiratory mechanics


    Dive into the research topics of 'Dead space estimates may not be independently associated with 28-day mortality in COVID-19 ARDS'. Together they form a unique fingerprint.

    Cite this