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.
MULTIFILE
Objectives Patients who underwent corrective surgery for tetralogy of Fallot (TOF) have increased long-term risk of cardiovascular morbidity and mortality. Yet, limited information is available on how to evaluate the risk in this population. Therefore, the aim of this study was to investigate the prognostic value of aerobic exercise capacity, along with other related parameters, at medium-term follow-up in adult patients with tetralogy of Fallot. Methods and results Between 2000 and 2003, 92 adults (age 26.2 ± 7.8 years; 63 male) with corrected TOF or TOF-type morphology underwent a cardiopulmonary exercise test (CPET) until exhaustion and echocardiography. During a mean follow-up of 7.3 ± 1.2 years (range 0.9 to 9.3 years), 2 patients died and 26 patients required at least 1 cardiac-related intervention at a mean age of 28.9 ± 7.9 years. Event-free survival tended to be higher in patients with the classical type of TOF (P = 0.061). At multivariate Cox analysis, age at CPET [hazard ratio (HR): 1.13, P = 0.006], age at correction (HR: 0.82, P = 0.037), right ventricular (RV) function (HR: 4.94, P = 0.001), QRS duration (HR: 1.02, P = 0.007), percentage of predicted peak oxygen uptake (peak VO2%) (HR: 0.96, P = 0.029) and ventilatory effi ciency slope (VE/VCO2 slope) (HR: 1.13, P = 0.021) were signifi cantly related to the incidence of death/cardiac-related intervention during medium follow-up. Conclusions Early corrective surgery and a well-preserved RV are associated with a better outcome in adults with corrected TOF. Furthermore, CPET provides important prognostic information; peak VO2% and VE/VCO2 slope are independent predictors for event-free survival in patients with corrected TOF.
Background: The coronavirus disease 2019 (COVID-19) pandemic is rapidly expanding across the world, with more than 100,000 new cases each day as of end-June 2020. Healthcare workers are struggling to provide the best care for COVID-19 patients. Approaches for invasive ventilation vary widely between and within countries and new insights are acquired rapidly. We aim to investigate invasive ventilation practices and outcome in COVID-19 patients in the Netherlands.Methods: PRoVENT-COVID ('study of PRactice of VENTilation in COVID-19') is an investigator-initiated national, multicenter observational study to be undertaken in intensive care units (ICUs) in The Netherlands. Consecutive COVID-19 patients aged 18 years or older, who are receiving invasive ventilation in the participating ICUs, are to be enrolled during a 10-week period, with a daily follow-up of 7 days. The primary outcome is ventilatory management (including tidal volume expressed as mL/kg predicted body weight and positive end-expiratory pressure expressed as cmH2O) during the first 3 days of ventilation. Secondary outcomes include other ventilatory variables, use of rescue therapies for refractory hypoxemia such as prone positioning and extracorporeal membrane oxygenation, use of sedatives, vasopressors and inotropes; daily cumulative fluid balances; acute kidney injury; ventilator-free days and alive at day 28 (VFD-28), duration of ICU and hospital stay, and ICU, hospital and 90-day mortality.Discussion: PRoVENT-COVID will be the largest observational study to date, with high density ventilatory data and major outcomes. There is urgent need for a better understanding of ventilation practices, and the effects of ventilator settings on outcomes in COVID-19 patients. The results of PRoVENT-COVID will be rapidly disseminated through electronic presentations, such as webinars and electronic conferences, and publications in international peer-reviewed journals. Access to source data will be made available through local, regional and national anonymized datasets on request, and after agreement of the PRoVENT-COVID steering committee.Trial Registration: PRoVENT-COVID is registered at clinicaltrials.gov (identifier NCT04346342).
