Improvements in Lung Diffusion Capacity following Pulmonary Rehabilitation in COPD with and without Ventilation Inhomogeneity.

BACKGROUND: Lung diffusing capacity (DLCO) and lung volume distribution predict exercise performance and are altered in COPD patients. If pulmonary rehabilitation (PR) can modify DLCO parameters is unknown. OBJECTIVES: To investigate changes in DLCO and ventilation inhomogeneity following a PR program and their relation with functional outcomes in patients with COPD. METHODS: This was a prospective, observational, multicentric study. Patients were evaluated before and after a standardized 3-week PR program. Functional assessment included body plethysmography, DLCO, transfer factor (KCO) and alveolar volume (VA), gas exchange, the 6-min walking test (6MWT) and exercise-related dyspnea. Patients were categorized according to the severity of airflow limitation and presence of ventilation inhomogeneity, identified by a VA/TLC <0.8. RESULTS: Two hundred and fifty patients completed the study. Baseline forced expiratory volume in 1 s (FEV1) % predicted (mean ± SD) was 50.5 ± 20.1 (76% males); 137 patients had a severe disease. General study population showed improvements in 6MWT (38 ± 55 m; p < 0.01), DLCO (0.12 ± 0.63 mmol × min-1 kPa-1; p < 0.01), lung function and dyspnea. Comparable improvements in DLCO were observed regardless of the severity of disease and the presence of ventilation inhomogeneity. While patients with VA/TLC <0.8 improved the DLCO increasing their VA (177 ± 69 ml; p < 0.01), patients with VA/TLC >0.8 improved their KCO (8.1 ± 2.8%; p = 0.019). The latter had also better baseline lung function and higher improvements in 6MWT (14.6 ± 6.7 vs. 9.0 ± 1.8%; p = 0.015). Lower DLCO at baseline was associated with lower improvements in 6MWT, the greatest difference being between subjects with very severe and mild DLCO impairment (2.7 ± 7.4 vs. 14 ± 2%; p = 0.049). CONCLUSIONS: In COPD patients undergoing a PR program, different pathophysiological mechanisms may drive improvements in DLCO, while ventilation inhomogeneity may limit improvements in exercise tolerance.

Exercise capacity and comorbidities in patients with obstructive sleep apnea.

STUDY OBJECTIVES: There are few studies evaluating (1) exercise capacity as assessed by the 6-minute walking distance (6MWD) test in large populations with obstructive sleep apnea (OSA); and (2) correlations with patients' comorbidities. METHODS: This study presents a cluster analysis performed on the data of 1,228 patients. Severity of exercise limitation was defined on the basis of 6MWD. RESULTS: Sixty-one percent showed exercise limitation (29.2% and 31.9% mild and severe exercise limitation, respectively). About 60% and 40% of patients were included in cluster 1 (CL1) and 2 (CL2), respectively. CL1 included younger patients with high prevalence of apneas, desaturations, and hypertension with better exercise tolerance. CL2 included older patients, all with chronic obstructive pulmonary disease (COPD), high prevalence of chronic respiratory failure (CRF), fewer apneas but severe mean desaturation, daytime hypoxemia, more severe exercise limitation, and exercise-induced desaturations. Only CRF and COPD significantly (P < .001) correlated with 6MWD < 85% of predicted value. 6MWD correlated positively with apnea-hypopnea index, oxygen desaturation index, nocturnal pulse oxygen saturation (SpO2), resting arterial oxygen tension, mean SpO2 on exercise, and negatively with age, body mass index, time spent during night with SpO2 < 90%, mean nocturnal desaturation, arterial carbon dioxide tension, and number of comorbidities. Patients without severe comorbidities had higher exercise capacity than those with severe comorbidities, (P < .001). Exercise limitation was significantly worse in OSA severity class I when compared to other classes (P < .001). CONCLUSIONS: A large number of patients with OSA experience exercise limitation. Older age, comorbidities such as COPD and CRF, OSA severity class I, severe mean nocturnal desaturation, and daytime hypoxemia are associated with worse exercise tolerance.

Implementation of a real-world based ICF set for the rehabilitation of respiratory diseases: a pilot study.

BACKGROUND: International Classification Functioning (ICF) Core Sets represent a holistic approach to functioning within rehabilitation field. Information-reporting efficacy of a rehabilitation-based Respiratory ICF set applied on a large scale throughout the ICS Maugeri network was tested. METHODS: A prospective multi-center study (May-November 2018) was conducted for all respiratory inpatients consecutively admitted for rehabilitation. Doctors, physiotherapists, psychologists, nurses used an electronic Respiratory ICF set (33 items among the ICF body functions, activity and participations components) at admission and at discharge to assess the disability changes. The ICF report qualifiers, from 0 (no impairment) to 4 (maximum impairment), guided clinical, diagnostic and rehabilitation prescriptions. RESULTS: 1886 patients (69.6±10.8 years; M=1045) were admitted (589 chronic obstructive pulmonary disease, 494 chronic respiratory failure [CRF], 21 prolonged mechanical ventilation [PMV], 496 with other respiratory diseases), of whom 15 died, and 117 were transferred to acute care. The mean length of stay was 23.1±11.8 days (range 1-122). The mean time to fill in the ICF set was 23.16±0.70 min. The rate of filled charts improved from 16% in May to 100% in November. The baseline distribution of the more severe qualifiers (>2) progressively increased from the whole sample to the PMV subgroup. After rehabilitation, in the whole sample and in the CRF and PMV subgroups, the severity qualifiers significantly decreased (P<0.0001), showing a positive effect of the intervention on patients' disability. CONCLUSIONS: Routine use of a Respiratory ICF set for chronic respiratory diseases helps to prepare a personalized rehabilitation program discriminating disability level in different respiratory diseases and assessing disability outcomes pre-post rehabilitation.