Objective Evaluation of pulmonary function impairment after COVID-19 in persistently symptomatic and asymptomatic patients of all disease severities and characterisation of risk factors. Methods Patients with confirmed SARS-CoV-2 infection underwent prospective follow-up with pulmonary function testing and blood gas analysis during steady-state cycle exercise 4 months after acute illness. Pulmonary function impairment (PFI) was defined as reduction below 80% predicted of DLCOcSB, TLC, FVC, or FEV1. Clinical data were analyzed to identify risk factors for impaired pulmonary function. Results 76 patients were included, hereof 35 outpatients with mild disease and 41 patients hospitalized due to COVID-19. Sixteen patients had critical disease requiring mechanical ventilation, 25 patients had moderate–severe disease. After 4 months, 44 patients reported persisting respiratory symptoms. Significant PFI was prevalent in 40 patients (52.6%) occurring among all disease severities. The most common cause for PFI was reduced DLCOcSB (n = 39, 51.3%), followed by reduced TLC and FVC. The severity of PFI was significantly associated with mechanical ventilation (p < 0.001). Further risk factors for DLCO impairment were COPD (p < 0.001), SARS-CoV-2 antibody-Titer (p = 0.014) and in hospitalized patients CT score. A decrease of paO2 > 3 mmHg during cycle exercise occurred in 1/5 of patients after mild disease course. Conclusion We characterized pulmonary function impairment in asymptomatic and persistently symptomatic patients of different severity groups of COVID-19 and identified further risk factors associated with persistently decreased pulmonary function. Remarkably, gas exchange abnormalities were revealed upon cycle exercise in some patients with mild disease courses and no preexisting pulmonary condition.

Background: Several studies have assessed predictors of weaning and extubation outcome in short-term mechanically ventilated patients, but there are only few studies on predictors of weaning from prolonged mechanical ventilation. Methods: Retrospective, single-center, observational study at a specialized national weaning center in Germany. Patients' medical records were reviewed to obtain data on demographics, comorbidities, respiratory indices, and the result of a prospectively documented, standardized spontaneous breathing trial (SBT) upon admission to the weaning center. Respiratory indices assessed were the ventilatory ratio (VR) and parameters derived from calculated mechanical power (MP). Predictors associated with failure of prolonged weaning and failure of the SBT were assessed using a binary logistic regression model. Results: A total of 263 prolonged mechanically ventilated, tracheotomized patients, treated over a 5-year period were analyzed. After 3 weeks of mechanical ventilation, patients with unsuccessful weaning failed a SBT more frequently and showed significantly increased values for inspiratory positive airway pressure, driving pressure, VR, absolute MP, and MP normalized to predicted body weight and dynamic lung-thorax compliance (LTC-MP). In the logistic regression analyses, variables independently correlated with weaning failure were female gender (adjusted odds ratio 0.532 [95% CI 0.291-0.973]; p = 0.040), obesity (body mass index ≥ 30 kg/m 2 ) (2.595 [1.210-5.562]; p = 0.014), COPD (3.209 [1.563-6.589]; p = 0.002), LTC-MP (3.470 [1.067-11.284]; p = 0.039), P a CO 2 on mechanical ventilation (1.101 [95% CI 1.034-1.173]; p = 0.003), and failure of the SBT (4.702 [2.250-9.825]; p < 0.001). In addition, female gender (0.401 [0.216-0.745]; p = 0.004), ; p = 0.046), and P a CO 2 on mechanical ventilation (1.157 [1.083-1.235]; p < 0.001) were independent risk factors for an unsuccessful SBT. Conclusions: In the present study, the derived predictors of weaning point to a crucial role of the workload imposed on respiratory muscles during spontaneous breathing. Mechanical power normalized to lung-thorax compliance was independently correlated with weaning outcome and may identify patients at high risk for weaning failure.

Background Mechanical power (MP) of artificial ventilation, the energy transferred to the respiratory system, is a chief determinant of adequate oxygenation and decarboxylation. Calculated MP, the product of applied airway pressure and minute ventilation, may serve as an estimate of respiratory muscle workload when switching to spontaneous breathing. The aim of the study was to assess MP’s discriminatory performance in predicting successful weaning from prolonged tracheostomy ventilation. Methods Prospective, observational study in 130 prolonged mechanically ventilated, tracheotomized patients in a specialized weaning center. Predictive weaning outcome ability of arterial blood gas analyses and indices derived from calculated MP at beginning and end of weaning was determined in terms of area under receiver operating characteristic curve (AUROC) and measures derived from k-fold cross-validation (likelihood ratios, diagnostic odds ratio, F1 score, and Matthews correlation coefficient [MCC]). Results Forty-four (33.8%) patients experienced weaning failure. Absolute MP showed poor discrimination in predicting outcome; whereas specific MP (MP normalized to dynamic lung-thorax compliance, LTCdyn-MP) had moderate diagnostic accuracy (MCC 0.38; AUROC 0.79, 95%CI [0.71‒0.86], p < 0.001), further improved by correction for corresponding mechanical ventilation PaCO2 (termed the power index of the respiratory system [PIrs]: MCC 0.52; AUROC 0.86 [0.79‒0.92], p < 0.001). Diagnostic performance of MP indices increased over the course of weaning, with maximum accuracy immediately before completion (LTCdyn-MP: MCC 0.49; AUROC 0.86 [0.78‒0.91], p < 0.001; PIrs: MCC 0.68; AUROC 0.92 [0.86‒0.96], p < 0.001). Conclusions MP normalized to dynamic lung-thorax compliance, a surrogate for applied power per unit of ventilated lung volume, accurately discriminated between low and high risk for weaning failure following prolonged mechanical ventilation.

Background Interstitial lung [ILD] disease and granulomatous lung disease [GLD] are rare respiratory disorders that have been associated with inflammatory bowel disease [IBD]. Clinical presentation is polymorphic and aetiology is unclear. Methods This was an ECCO-CONFER project. Cases of concomitant ILD or GLD and IBD, or drug-induced ILD/GLD, were collected. The criteria for diagnosing ILD and GLD were based on definitions from the American Thoracic Society and the European Respiratory Society and on the discretion of reporting clinician. Results We identified 31 patients with ILD. The majority had ulcerative colitis [UC] [n = 22]. Drug-related ILD was found in 64% of these patients, 25 patients [80.6%] required hospitalisation, and one required non-invasive ventilation. The causative drug was stopped in all drug-related ILD, and 87% of patients received systemic steroids. At follow-up, 16% of patients had no respiratory symptoms, 16% had partial improvement, 55% had ongoing symptoms, and there were no data in 13%. One patient was referred for lung transplantation, and one death from lung fibrosis was reported. We also identified 22 GLD patients: most had Crohn’s disease [CD] [n = 17]. Drug-related GLD was found in 36% of patients and 10 patients [45.4%] required hospitalisation. The causative drug was stopped in all drug-related GLD, and 81% of patients received systemic steroids. Remission of both conditions was achieved in almost all patients. Conclusions ILD and GLD, although rare, can cause significant morbidity. In our series, over half of cases were drug-related and therefore focused pharmacovigilance is needed to identify and manage these cases.