ABSTRACT
Background: Severe coronavirus disease 2019 (COVID-19) may require veno-venous extracorporeal membrane oxygenation (V-V ECMO). While V-V ECMO is offered in severe lung injury to COVID-19, long-term respiratory follow-up in these patients is missing. Therefore, we aimed at providing comprehensive data on the long-term respiratory effects of COVID-19 requiring V-V ECMO support during the acute phase of infection. Methods: In prospective observational cohort study design, patients with severe COVID-19 receiving invasive mechanical ventilation and V-V ECMO (COVID group, n = 9) and healthy matched controls (n = 9) were evaluated 6 months after hospital discharge. Respiratory system resistance at 5 and 19 Hz (R5, R19), and the area under the reactance curve (AX5) was evaluated using oscillometry characterizing total and central airway resistances, and tissue elasticity, respectively. R5 and R19 difference (R5-R19) reflecting small airway function was also calculated. Forced expired volume in seconds (FEV1), forced expiratory vital capacity (FVC), functional residual capacity (FRC), carbon monoxide diffusion capacity (DLCO) and transfer coefficient (KCO) were measured. Results: The COVID group had a higher AX5 and R5-R19 than the healthy matched control group. However, there was no significant difference in terms of R5 or R19. The COVID group had a lower FEV1 and FVC on spirometry than the healthy matched control group. Further, the COVID group had a lower FRC on plethysmography than the healthy matched control group. Meanwhile, the COVID group had a lower DLCO than healthy matched control group. Nevertheless, its KCO was within the normal range. Conclusion: Severe acute COVID-19 requiring V-V ECMO persistently impairs small airway function and reduces respiratory tissue elasticity, primarily attributed to lung restriction. These findings also suggest that even severe pulmonary pathologies of acute COVID-19 can manifest in a moderate but still persistent lung function impairment 6 months after hospital discharge. Trial registration: NCT05812196.
ABSTRACT
OBJECTIVES: Cardiopulmonary exercise test (CPET) is a widely used examination to predict the prognosis of many chronic pulmonary diseases, and it has also been tested in systemic sclerosis (SSc) with a focus on the development of pulmonary hypertension. CPET is a highly informative non-invasive tool that provides a more complex information than conventional lung function tests to predict the course of cardiopulmonary diseases, as it provides a general overview of the aerobic metabolism, influenced by pulmonary, cardiovascular and peripheral muscle function. The purpose of this investigation was to assess if the progression and the development of poor overall disease outcome in SSc can be predicted by this method. METHODS: Twenty-nine SSc patients were investigated prospectively with standard follow-up plus CPET for a mean of 3.7 years to match the results of conventional evaluation modalities and CPET. A composite end-point of several serious outcomes reflecting SSc-related vascular and cardiopulmonary damage was set up, and the predictive value of and correlations between the CPET parameters and resting lung function and echocardiography variables were assessed. RESULTS: None of the clinical parameters, resting lung function or echocardiographic test results proved to be predictive of the development of the endpoint of poor prognosis in this cohort. In contrast, several CPET parameters were found to discriminate between SSc patients with or without adverse outcome. The detection of desaturation (at any CPET test) was associated with a higher risk of poor prognosis (OR:5.265). VO2 and VE/VCO2 at baseline correlated with the annual decrease in FVC, anaerobic threshold with the development of digital ulcers, and VE/VO2 with the increase in pulmonary arterial pressure. CONCLUSIONS: Several CPET parameters obtained at the beginning of follow-up are informative of the appearance of various adverse end-points. CPET is a feasible examination in the care of SSc patients and provides excess information to current standard follow-up examinations.
