Objective. After laryngectomy, the breathing resistance of heat and moisture exchangers may limit exercise capacity. Breathing gas analysis during cardiopulmonary exercise testing is not possible using regular masks. This study tested the feasibility of cardiopulmonary exercise testing with a heat and moisture exchanger in situ, using an in-house designed connector. Additionally, we explored the effect of different heat and moisture exchanger resistances on exercise capacity in this group. Methods. Ten participants underwent two cardiopulmonary exercise tests using their daily life heat and moisture exchanger (0.3 hPa or 0.6 hPa) and one specifically developed for activity (0.15 hPa). Heat and moisture exchanger order was randomised and blinded.Results. All participants completed both tests. No (serious) adverse events occurred. Only four subjects reached a respiratory exchange ratio of more than 1.1 in at least one test. Maximum exercise levels using heat and moisture exchangers with different resistances did not differ. Conclusion. Cardiopulmonary exercise testing in laryngectomees with a heat and moisture exchanger is feasible; however, the protocol does not seem appropriate to reach this group's maximal exercise capacity. Lowering heat and moisture exchanger resistance does not increase exercise capacity in this sample.
No clinical characteristics, particularly not sputum characteristics, can guide antibiotic prescription in patients with mild to severe COPD exacerbations
This study aimed to identify simple rules for allocating chronic obstructive pulmonary disease (COPD) patients to clinical phenotypes identified by cluster analyses.Data from 2409 COPD patients of French/Belgian COPD cohorts were analysed using cluster analysis resulting in the identification of subgroups, for which clinical relevance was determined by comparing 3-year all-cause mortality. Classification and regression trees (CARTs) were used to develop an algorithm for allocating patients to these subgroups. This algorithm was tested in 3651 patients from the COPD Cohorts Collaborative International Assessment (3CIA) initiative.Cluster analysis identified five subgroups of COPD patients with different clinical characteristics (especially regarding severity of respiratory disease and the presence of cardiovascular comorbidities and diabetes). The CART-based algorithm indicated that the variables relevant for patient grouping differed markedly between patients with isolated respiratory disease (FEV1, dyspnoea grade) and those with multi-morbidity (dyspnoea grade, age, FEV1 and body mass index). Application of this algorithm to the 3CIA cohorts confirmed that it identified subgroups of patients with different clinical characteristics, mortality rates (median, from 4% to 27%) and age at death (median, from 68 to 76 years).A simple algorithm, integrating respiratory characteristics and comorbidities, allowed the identification of clinically relevant COPD phenotypes.
