Predictors and changes of physical activity in idiopathic pulmonary fibrosis.

BACKGROUND: Different clinical predictors of physical activity (PA) have been described in idiopathic pulmonary fibrosis (IPF), but studies are lacking evaluating the potential role of muscle strength and anxiety and depression symptoms in PA limitation. Moreover, little is known about the impact of changes in PA in the course of the disease. The aim of the present study was to investigate the relationship between baseline PA and a wide range of variables in IPF, to assess its longitudinal changes at 12 months and its impact on progression free-survival. METHODS: PA was assessed by accelerometer and physiological, clinical, psychological factors and health-related quality of life were evaluated in subjects with IPF at baseline and at 12 month follow-up. Predictors of PA were determined at baseline, evolution of PA parameters was described and the prognostic role of PA evolution was also established. RESULTS: Forty participants with IPF were included and 22 completed the follow-up. At baseline, subjects performed 5765 (3442) daily steps and spent 64 (44) minutes/day in moderate to vigorous PA. Multivariate regression models showed that at baseline, a lower six-minute walked distance, lower quadriceps strength (QMVC), and a higher depression score in the Hospital Anxiety and Depression scale were associated to lower daily step number. In addition, being in (Gender-Age-Physiology) GAP III stage, having a BMI ≥ 25 kg/m2 and lower QMVC or maximum inspiratory pressure were factors associated with sedentary behaviour. Adjusted for age, gender and forced vital capacity (FVC) (%pred.) a lower progression-free survival was evidenced in those subjects that decreased PA compared to those that maintained, or even increased it, at 12 months [HR 12.1 (95% CI, 1.9-78.8); p = 0.009]. CONCLUSION: Among a wide range of variables, muscle strength and depression symptoms have a predominant role in PA in IPF patients. Daily PA behaviour and its evolution should be considered in IPF clinical assessment and as a potential complementary indicator of disease prognosis.

Deficient muscle regeneration potential in sarcopenic COPD patients: Role of satellite cells.

Sarcopenia is a major comorbidity in chronic obstructive pulmonary (COPD). Whether deficient muscle repair mechanisms and regeneration exist in the vastus lateralis (VL) of sarcopenic COPD remains debatable. In the VL of control subjects and severe COPD patients with/without sarcopenia, satellite cells (SCs) were identified (immunofluorescence, specific antibodies, anti-Pax-7, and anti-Myf-5): activated (Pax-7+/Myf-5+), quiescent/regenerative potential (Pax-7+/Myf-5-), and total SCs, nuclear activation (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling [TUNEL]), and muscle fiber type (morphometry and slow- and fast-twitch, and hybrid fibers), muscle damage (hematoxylin-eosin staining), muscle regeneration markers (Pax-7, Myf-5, myogenin, and MyoD), and myostatin levels were identified. Compared to controls, in VL of sarcopenic COPD patients, myostatin content, activated SCs, hybrid fiber proportions, TUNEL-positive cells, internal nuclei, and muscle damage significantly increased, while quadriceps muscle strength, numbers of Pax-7+/Myf-5- and slow- and fast-twitch, and hybrid myofiber areas decreased. In the VL of sarcopenic and nonsarcopenic patients, TUNEL-positive cells were greater, whereas muscle regeneration marker expression was lower than in controls. In VL of severe COPD patients regardless of the sarcopenia level, the muscle regeneration process is triggered as identified by SC activation and increased internal nuclei. Nonetheless, a lower regenerative potential along with significant alterations in muscle phenotype and damage, and increased myostatin were prominently seen in sarcopenic COPD.

Feasibility, tolerability, and effects of exercise-based prehabilitation after neoadjuvant therapy in esophagogastric cancer patients undergoing surgery: an interventional pilot study.

Patients requiring surgery for locally advanced esophagogastric cancer often require neoadjuvant therapy (NAT), which may have a detrimental impact on cardiorespiratory reserve. The aims of this study were to investigate the feasibility and tolerability of a 5-week preoperative high-intensity interval training program after NAT, and to assess the potential effects of the training protocol on exercise capacity, muscle function, and health-related quality of life (HRQL). We prospectively studied consecutive patients with resectable locally advanced esophageal and gastric cancer in whom NAT was planned (chemo- or chemoradiotherapy). Feasibility was assessed with the TELOS (Technological, Economics, Legal, Operational, and Scheduling) components, and data on exercise tolerability (attendance and occurrence of adverse or unexpected events). Exercise capacity was assessed with peak oxygen uptake (VO2peak) in a cardiopulmonary exercise test at baseline, post-NAT, and following completion of a high-intensity interval exercise training (25 sessions). Changes in muscle strength and HRQL were also assessed. Of 33 recruited subjects (mean age 65 years), 17 received chemoradiotherapy and 16 chemotherapy. All the TELOS components were addressed before starting the intervention; from a total of 17 questions considered as relevant for a successful implementation, seven required specific actions to prevent potential concerns. Patients attended a mean of 19.4 (6.4) exercise sessions. The predefined level of attendance (≥15 sessions of scheduled sessions) was achieved in 27 out of 33 (81.8%) patients. Workload progression was adequate in 24 patients (72.7%). No major adverse events occurred. VO2peak decreased significantly between baseline and post-NAT (19.3 vs. 15.5 mL/Kg/min, P < 0.05). Exercise led to a significant improvement of VO2peak (15.5 vs. 19.6 mL/kg/min, P < 0.05). Exercise training was associated with clinically relevant improvements in some domains of HRQL, with the social and role function increasing by 10.5 and 11.6 points, respectively, and appetite loss and fatigue declining by 16 and 10.5, respectively. We conclude that a structured exercise training intervention is feasible and safe following NAT in patients with esophagogastric cancer, and it has positive effects to restore exercise capacity to baseline levels within 5 weeks with some improvements in HRQL.

Ten Research Questions for Improving COPD Care in the Next Decade.

With the 60th anniversary of the CIBA symposium, it is worth evaluating research questions that should be prioritized in the future. Coming research initiatives can be summarized in 10 main areas. (1) From epidemiology the impact of new forms of electronic cigarettes on prevalence and mortality of COPD will be sought. (2) The study of the disease endotypes and its relationship phenotypes will have to be unraveled in the next decade. (3) Diagnosis of COPD faces several challenges opening the possibility of a change in the definition of the disease itself. (4) Patients' classification and risk stratification will need to be clarified and reassessed. (5) The asthma-COPD overlap dilemma will have to be clarified and define whether both conditions represent one only chronic airway disease again. (6) Integrating comorbidities in COPD care will be key in a progressively ageing population to improve clinical care in a chronic care model. (7) Nonpharmacological management have areas for research including pulmonary rehabilitation and vaccines. (8) Improving physical activity should focus research because of the clear prognostic impact. (9). Pharmacological therapies present several challenges including efficacy and safety issues with current medications and the development of biological therapy. (10) The definition, identification, categorization and specific therapy of exacerbations will also be an area of research development. During the next decade, we have a window of opportunity to address these research questions that will put us on the path for precision medicine.

Sex differences in function and structure of the quadriceps muscle in chronic obstructive pulmonary disease patients.

Chronic obstructive pulmonary disease (COPD) is a complex disorder with extrapulmonary manifestations. Even though there is some knowledge regarding sex differences in the lung disease, little is known about extrapulmonary manifestations. Our aim was to analyze the specific profile of muscle dysfunction, structure, and biology in COPD women. Twenty-one women and 19 men with stable COPD as well as 15 controls were included. Nutritional status, physical activity, lung and muscle function, exercise capacity, and quality of life were assessed. In addition, blood, breath condensate, and quadriceps muscle samples were tested for inflammatory markers. Moreover, fiber phenotype, signs of damage-regeneration, and the expression of key genes linked to myogenesis and inflammation were assessed in the muscle. Inflammatory markers were increased in all body compartments but no correlation was found among them. Muscle dysfunction was present in both COPD groups but was more marked in women. The opposite occurred with the increase in the percentage of type II fibers that was lower in women despite a similar level of airway obstruction as in men. Female COPD also showed higher signs of muscle damage than COPD men who, in contrast, exhibited slightly higher signs of regeneration. We conclude that sex influences muscle phenotype and function in COPD.

Quadriceps muscle weakness and atrophy are associated with a differential epigenetic profile in advanced COPD.

Epigenetic mechanisms regulate muscle mass and function in models of muscle dysfunction and atrophy. We assessed whether quadriceps muscle weakness and atrophy are associated with a differential expression profile of epigenetic events in patients with advanced COPD (chronic obstructive pulmonary disease). In vastus lateralis (VL) of sedentary severe COPD patients (n=41), who were further subdivided into those with (n=25) and without (n=16) muscle weakness and healthy controls (n=19), expression of muscle-enriched miRNAs, histone acetyltransferases (HATs) and deacetylases (HDACs), growth and atrophy signalling markers, total protein and histone acetylation, transcription factors, small ubiquitin-related modifier (SUMO) ligases and muscle structure were explored. All subjects were clinically evaluated. Compared with controls, in VL of all COPD together and in muscle-weakness patients, expression of miR-1, miR-206 and miR-27a, levels of lysine-acetylated proteins and histones and acetylated histone 3 were increased, whereas expression of HDAC3, HDAC4, sirtuin-1 (SIRT-1), IGF-1 (insulin-like growth factor-1) were decreased, Akt (v-akt murine thymoma viral oncogene homologue 1) expression did not differ, follistatin expression was greater, whereas myostatin expression was lower, serum reponse factor (SRF) expression was increased and fibre size of fast-twitch fibres was significantly reduced. In VL of severe COPD patients with muscle weakness and atrophy, epigenetic events regulate muscle differentiation rather than proliferation and muscle growth and atrophy signalling, probably as feedback mechanisms to prevent those muscles from undergoing further atrophy. Lysine-hyperacetylation of histones may drive enhanced protein catabolism in those muscles. These findings may help design novel therapeutic strategies (enhancers of miRNAs promoting myogenesis and acetylation inhibitors) to selectively target muscle weakness and atrophy in severe COPD.

Poor outcomes and satisfaction in adolescent idiopathic scoliosis surgery: the relevance of the body mass index and self-image.

INTRODUCTION AND AIM: The purpose of this study was to evaluate patients with adolescent idiopathic scoliosis (AIS) to determine whether a low body mass index (BMI) influences surgery outcomes and satisfaction. METHODS: There were 39 patients in this prospective 3-year cohort study. The BMI, Cobb angle, the Body Shape Questionnaire 14 (BSQ-14), the Scoliosis Research Society Questionnaire 22 (SRS-22) and eight satisfaction questions results were obtained. Having a BMI greater than or less than 18 kg/m(2) was used as a determiner to allocate patients to groups. As a low BMI is related to the presence of a disturbance in body perception, patients were also dichotomized by using the BSQ-14. RESULTS: All scales were worse in both slimmer patients and the group with a body perception disorder. The group with a BMI <18 kg/m(2) obtained a total of 82.31 points in the SRS-22, and it was 93.45 points for the group with a BMI >18 kg/m(2) (p = 0.001). In terms of satisfaction, the percentage of patients that would undergo surgery again was 30.8 vs 69.2 % (p = 0.054). Patients with an alteration of physical perception obtained a total SRS-22 of 82.90 points versus 96.10 points in the control group (p < 0.001). No differences in terms of the Cobb correction (p = 0.29) or the percentage of correction (p = 0.841) were found in any case. CONCLUSION: The alteration of physical perception and a low BMI negatively affect the outcomes in AIS surgery, regardless of the curve magnitude and the percentage of correction. Considerable care should be taken in recommending surgical correction to these patients.

[National Survey on the Activity of Lung Function Laboratories. Effects During the SARS-COV-2 Pandemic]. / Encuesta sobre la actividad de los laboratorios de función pulmonar. Efectos durante la pandemia por SARS-CoV-2.

Introduction: Following the SARS-CoV-2 pandemic in March 2020, pulmonary function testing (PFT) laboratories underwent a transformation, with a reduction in the number of tests or closure in some cases. The aim of this work was to know the activity of PFT in Spain and the modification of this activity due to the pandemic. Material and methods: A protocolised survey was carried out to members of the PFT laboratories through the Spanish Society of Pneumology and Thoracic Surgery (SEPAR). Results: Thirty-nine hospitals in Spain responded. The pulmonary function tests most frequently performed in the PFT laboratories were forced spirometry with bronchodilator test (100%), body plethysmography (97.4%), CO transfer capacity (97.4%), respiratory muscle strength measured in the mouth (97.4%), 6-minute walking test (94.7%), measurement of exhaled fraction of nitric oxide (92.3%) and incremental exercise test (71.8%).The pandemic led to a significant decrease in the number of tests (35.4%) during 2020 with subsequent recovery in 2021, without reaching pre-pandemic values.The most important changes were increased examination times, working with personal protective equipment and ventilation of the rooms. The performance of the nasopharyngeal swab for SARS-CoV2 testing prior to the tests was not homogeneous in the PFT laboratories. Conclusions: Most hospitals are sufficiently equipped to perform the most common pulmonary function tests. The pandemic resulted in a loss of activity in all hospitals.

Body composition in adolescent idiopathic scoliosis.

STUDY DESIGN: A controlled prospective cross-sectional case study. OBJECTIVE: To investigate body mass index (BMI) and corporal composition in girls with adolescent idiopathic scoliosis (AIS) and compare them with a normal population matched by sex and age. There is controversy as to whether there are real anthropometric alterations in patients with AIS. Relative to the weight or the BMI, some studies find differences and other studies do not detect them. AIS and anorexia nervosa (AN) make their debut during adolescence and both may be associated with an alteration of their subjective physical perception. Some authors propose a link between AIS and AN supported both by an alteration of physical perception and lower BMI. No studies on body composition in AIS have been published. METHODS: Adolescent idiopathic scoliosis patient surgery candidates during 2008 were studied. Body composition was evaluated using the bioelectrical impedance analysis (Bodystat, Isle of Man, UK). A study population of more than 5,000 patients that was published by Kyle et al. (Nutrition 17:534-541, 2001) was chosen as a control (group 1). Another control group (group 2) of healthy volunteers matched by sex and age was selected among a school age and university population in Barcelona, Spain. A variance analysis was used to analyze differences between the mean values of the control group 1, the European control group, and the AIS patient surgery candidates (Epiinfo 6.2001). Comparisons between the AIS patients and control group 2 were performed with the T Student test of unpaired samples using the SPSS 15.0 (Statistical Package Social Science) software. RESULTS: Twenty-seven women with a mean age of 17.4 years. BMI was 18.9 kg/m(2) (SD 1.7; 95 % CI 18.31-19.73). In the variance analysis, a significant difference between AIS and group 1 in BMI was observed (21.0 vs. 18.9, p = 0.000004); fat-free mass (FFM = 42.6 vs. 38.9, p = 0.0000009) and fat mass (FM = 15.6 vs. 13.7, p = 0.03). Significant differences in BMI (22.13 vs. 18.9, p = 0.001; 95 % CI difference 1.85-4.60), fat mass index (FMi = 7.17 vs. 4.97, p = 0.000; 95 % CI difference 1.36-3.05) and fat-free mass index (FFMi = 14.95 vs. 13.09, p = 0.001; 95 % CI difference 0.26-1.86) between AIS and group 2 were also seen. CONCLUSION: The conclusion is that there is a real alteration of body composition in AIS. The BMI, FFMi and FMi are lower than in the general population in the series under study.

Injury of peripheral muscles in smokers with chronic obstructive pulmonary disease.

Muscle injury has clinical relevance in diseased individuals because it is associated with muscle dysfunction in terms of decreased strength and/or endurance. This study was aimed at answering three questions: whether the presence of chronic obstructive pulmonary disease (COPD) is associated with peripheral muscle injury; whether muscle injury is associated with some of the relevant functional impairment in the muscles; and whether muscle injury can be solely justified by deconditioning. Twenty-one male COPD patients were eligible for the study. Seven healthy volunteers recruited from the general population were included as controls. Function of the quadriceps muscle was assessed through specific single-leg exercise (strength and endurance). Cellular (light microscopy) and subcellular (electron microscopy) techniques were used to evaluate muscle injury on biopsies from the vastus lateralis muscle. Signs of injury were found in muscles from both control and COPD patients, not only in cases showing severe airflow obstruction but also in the mild or moderate stages of the disease. Current smoking and presence of COPD were significantly associated with increased injury of the muscle as assessed by light and electron microscopy techniques. The authors conclude that peripheral muscle injury is evident in mild, moderate, and severe stages of COPD even in the absence of respiratory failure, hypercapnia, chronic steroid treatment, low body weight, or some coexisting disease. These findings support the theory that systemic factors with deleterious effect are acting on peripheral muscles of smokers with COPD, increasing the susceptibility of the muscle fibers to membrane and sarcomere injury.

Respiratory and Peripheral Muscle Weakness and Body Composition Abnormalities in Non-Cystic Fibrosis Bronchiectasis Patients: Gender Differences.

As demonstrated in COPD, bronchiectasis patients may experience respiratory and peripheral muscle dysfunction. We hypothesized that respiratory and peripheral (upper and lower limbs) muscle function and nutritional status may be more significantly altered in female than in males for identical age and disease severity. In mild-to-moderate bronchiectasis patients (n = 150, 114 females) and 37 controls (n = 37, 21 females), radiological extension, maximal inspiratory and expiratory pressures (MIP and MEP), sniff nasal inspiratory pressure (SNIP), hand grip and quadriceps muscle strengths, body composition, and blood analytical biomarkers were explored. Compared to the controls, in all bronchiectasis patients (males and females), BMI, fat-free mass index (FFMI), fat tissue, upper and lower limb muscle strength, and respiratory muscle strength significantly declined, and FFMI, fat tissue, and quadriceps muscle function were significantly lower in female than male patients. In patients with mild-to-moderate bronchiectasis, respiratory and peripheral muscle function is significantly impaired and only partly related to lung disease status. Quadriceps muscle strength was particularly weakened in the female patients and was negatively associated with their exercise tolerance. Muscle weakness should be therapeutically targeted in bronchiectasis patients. Body composition and peripheral muscle function determination should be part of the comprehensive clinical assessment of these patients.

Higher mortality and intubation rate in COVID-19 patients treated with noninvasive ventilation compared with high-flow oxygen or CPAP.

The effectiveness of noninvasive respiratory support in severe COVID-19 patients is still controversial. We aimed to compare the outcome of patients with COVID-19 pneumonia and hypoxemic respiratory failure treated with high-flow oxygen administered via nasal cannula (HFNC), continuous positive airway pressure (CPAP) or noninvasive ventilation (NIV), initiated outside the intensive care unit (ICU) in 10 university hospitals in Catalonia, Spain. We recruited 367 consecutive patients aged ≥ 18 years who were treated with HFNC (155, 42.2%), CPAP (133, 36.2%) or NIV (79, 21.5%). The main outcome was intubation or death at 28 days after respiratory support initiation. After adjusting for relevant covariates and taking patients treated with HFNC as reference, treatment with NIV showed a higher risk of intubation or death (hazard ratio 2.01; 95% confidence interval 1.32-3.08), while treatment with CPAP did not show differences (0.97; 0.63-1.50). In the context of the pandemic and outside the intensive care unit setting, noninvasive ventilation for the treatment of moderate to severe hypoxemic acute respiratory failure secondary to COVID-19 resulted in higher mortality or intubation rate at 28 days than high-flow oxygen or CPAP. This finding may help physicians to choose the best noninvasive respiratory support treatment in these patients.Clinicaltrials.gov identifier: NCT04668196.

[Could Inspiratory Muscle Function Be an Equivalent of Lung Hyperinflation in COPD Patients?] / ¿La función muscular inspiratoria podría ser un equivalente de la insuflación pulmonar en los pacientes con EPOC?

Introduction: Chronic obstructive pulmonary disease (COPD) is the respiratory disease that causes the greatest morbidity and mortality worldwide. Lung function parameters and systemic manifestations have been defined as prognostic factors; however, they have limitations. The aim of this study was to analyze whether inspiratory muscle strength could reflect lung hyperinflation, and therefore serve as a prognostic factor in COPD patients. Method: We selected COPD patients who had performed a non-invasive respiratory muscle strength assessment and lung function testing between January 2015 and October 2017. Mortality was subsequently followed up until March 1, 2020. Results: We included 140 COPD patients (GOLD stage I 5%, II 73.4%, and III 21.6%), of whom 10% died during follow-up. Bronchial obstruction, defined by FEV1, was a good predictor of mortality (p = 0.004). Lung hyperinflation, defined as inspiratory capacity (IC)/total lung capacity less than 25 and IC less than 65% of predicted increased mortality in COPD patients (p = 0.001 and p = 0.06, respectively). In this cohort, inspiratory muscle strength, measured by SNIP, was not a prognostic factor (p = 0.629). Conclusion: In COPD patients, lung hyperinflation is a prognostic factor, but inspiratory muscle function is not. Inspiratory muscle function in COPD patients depends not only on lung mechanics but also on intrinsic muscle factors.

Incidence of pulmonary embolism in patients with non-invasive respiratory support during COVID-19 outbreak.

While the incidence of thrombotic complications in critically ill patients is very high, in patients under non-invasive respiratory support (NIS) is still unknown. The specific incidence of thrombotic events in each of the clinical scenarios within the broad spectrum of severity of COVID-19, is not clearly established, and this has not allowed the implementation of thromboprophylaxis or anticoagulation for routine care in COVID-19. Patients admitted in a semi-critical unit treated initially with NIS, especially Continuous-Positive Airway Pressure (CPAP), were included in the study. The cumulative incidence of pulmonary embolism was analyzed and compared between patients with good response to NIS and patients with clinical deterioration that required orotracheal intubation. 93 patients were included and 16% required mechanical ventilation (MV) after the NIS. The crude cumulative incidence of the PE was 14% (95%, CI 8-22) for all group. In patients that required orotracheal intubation and MV, the cumulative incidence was significantly higher [33% (95%, CI 16-58)] compared to patients that continued with non-invasive support [11% (CI 5-18)] (Log-Rank, p = 0.013). Patients that required mechanical ventilation were at higher risk of PE for a HR of 4.3 (95%CI 1.2-16). In conclusion, cumulative incidence of PE is remarkably higher in critically patients with a potential impact in COVID-19 evolution. In this context, patients under NIS are a very high-risk group for developing PE without a clear strategy regarding thromboprophylaxis.

Respiratory muscle senescence in ageing and chronic lung diseases.

Ageing is a progressive condition that usually leads to the loss of physiological properties. This process is also present in respiratory muscles, which are affected by both senescent changes occurring in the whole organism and those that are more specific for muscles. The mechanisms of the latter changes include oxidative stress, decrease in neurotrophic factors and DNA abnormalities. Ageing normally coexists with comorbidities, including respiratory diseases, which further deteriorate the structure and function of respiratory muscles. In this context, changes intrinsic to ageing become enhanced by more specific factors such as the impairment in lung mechanics and gas exchange, exacerbations and hypoxia. Hypoxia in particular has a direct effect on muscles, mainly through the expression of inducible factors (hypoxic-inducible factor), and can result in oxidative stress and changes in DNA, decrease in mitochondrial biogenesis and defects in the tissue repair mechanisms. Intense exercise can also cause damage in respiratory muscles of elderly respiratory patients, but this can be followed by tissue repair and remodelling. However, ageing interferes with muscle repair by tampering with the function of satellite cells, mainly due to oxidative stress, DNA damage and epigenetic mechanisms. In addition to the normal process of ageing, stress-induced premature senescence can also occur, involving changes in the expression of multiple genes but without modifications in telomere length.

Is iron deficiency modulating physical activity in COPD?

There is evidence that iron plays a key role in the adequate functioning of skeletal muscle. While it has been demonstrated that nonanemic iron deficiency (NAID) affects exercise tolerance and response to exercise training in patients with COPD, the impact on daily physical activities (DPAs) remains unknown. Eighteen COPD patients with NAID (ferritin <100 ng/mL or ferritin 100-299 ng/mL with a transferrin saturation <20%) and 18 COPD patients without this abnormality, matched for age, gender, and the degree of airflow limitation (control group), were enrolled to the study. The primary outcome was the level of DPA assessed by accelerometers. Patients were (mean [SD]) 66 (7) years and were mostly male (70%) and former smokers (52%). Their forced expiratory volume at 1 second was 41 (16)% predicted, carbon monoxide diffusing capacity was 47 (14)% predicted and oxygen arterial pressure reached 70 (11) mmHg. DPA and the number of steps per day were lower in NAID COPD patients compared with controls (physical activity level 1.39 vs 1.59, P<0.05; and 4,402 vs 6,975 steps/day, P<0.05, respectively). The percentage of patients with increased time spent sitting per day (>6 hours) was higher in patients with NAID compared with controls (73% vs 37%, P<0.05). In addition, the percentage of patients doing moderate to vigorous physical activity per day (>3 metabolic equivalents of task, at least 30 minutes) was lower in this group (66% vs 100%, P<0.05). The presence of iron deficiency was associated with reduced DPA in COPD patients. Further studies are needed to evaluate iron reposition and their impact on the level of physical activity in these patients.

[Short-stay respiratory unit: a new option for inpatient care]. / Unidad neumológica de estancia corta: un nuevo dispositivo asistencial de hospitalización.

OBJECTIVE: The current pressure on conventional inpatient care units represents a very serious problem for respiratory medicine departments. The aim of this study was to analyze the impact of a new instrument --a short-stay respiratory unit-- on the quality of care delivered by the respiratory medicine department of a tertiary care hospital. MATERIAL AND METHODS: The short-stay respiratory unit consisted of 4 conventional hospital beds managed by a pulmonologist. The beds were only used to treat patients diagnosed with exacerbation of chronic obstructive pulmonary disease or bronchial asthma, community-acquired pneumonia, or suspected lung cancer, and stays were intended to only last for up less than to 4 days. Analyzing a range of healthcare quality variables, we compared the quality of care delivered during the first 6 months the unit was in operation (October 2005 to March 2006) to that delivered in the same period 12 months earlier. RESULTS: The study included 147 patients admitted to the short-stay unit. The mean (SD) age of the patients was 64 (17) years and 79% were men. The mean length of stay was 3.3 (1.6) days--only 1.4% of patients stayed for longer than 4 days--and the readmission rate was 2.7%. There were no deaths. The existence of the short-stay respiratory unit led to a 30% decrease in the overall mean length of stay in the respiratory medicine department (11.8 [4.6] vs 8.3 [2.6] days; P< .001), and the readmission rate fell from 21% to 15% (P< .05). While there were no differences in mortality between the 2 periods, the complexity of diseases treated by the respiratory medicine department showed an increase of 9.2% (P< .001). CONCLUSIONS: A short-stay respiratory unit can improve the efficiency of care delivered by a respiratory medicine department by reducing both the mean duration of hospitalization and the readmission rate, without a reduction in the complexity of diseases treated or a need for additional resources.

[Activation of satellite cells in the intercostal muscles of patients with chronic obstructive pulmonary disease]. / Activación de células satélite en el músculo intercostal de pacientes con EPOC.

OBJECTIVE: The respiratory muscles of patients with chronic obstructive pulmonary disease (COPD) display evidence of structural damage in parallel with signs of adaptation. We hypothesized that this can only be explained by the simultaneous activation of satellite cells. The aim of this study was to analyze the number and activation of those cells along with the expression of markers of microstructural damage that are frequently associated with regeneration. PATIENTS AND METHODS: The study included 8 patients with severe COPD (mean [SD] forced expiratory volume in 1 second, 33% [9%] of predicted) and 7 control subjects in whom biopsies were performed of the external intercostal muscle. The samples were analyzed by light microscopy to assess muscle fiber phenotype, electron microscopy to identify satellite cells, and real-time polymerase chain reaction to analyze the expression of the following markers: insulin-like growth factor 1, mechano growth factor, and embryonic and perinatal myosin heavy chains (MHC) as markers of microstructural damage; Pax-7 and m-cadherin as markers of the presence and activation of satellite cells, respectively; and MHC-I, IIa, and IIx as determinants of muscle fiber phenotype. RESULTS: The patients had larger fibers than healthy subjects (54 [6] vs 42 [4] microm(2); P< .01) with a similar or slightly increased proportion of satellite cells, as measured by ultrastructural analysis (4.3% [1%] vs 3.7% [3.5%]; P>.05) or expression of Pax-7 (5.5 [4.1] vs 1.6 [0.8] arbitrary units [AU]; P< .05). In addition, there was greater activation of satellite cells in the patients, as indicated by increased expression of m-cadherin (3.8 [2.1] vs 1.0 [1.2] AU; P=.05). This was associated with increased expression of markers of microstructural damage: insulin-like growth factor 1, 0.35 (0.34) vs 0.09 (0.08) AU (P< .05); mechano growth factor, 0.45 (0.55) vs 0.13 (0.17) AU (P=.05). CONCLUSIONS: The intercostal muscles of patients with severe COPD show indirect signs of microstructural damage accompanied by satellite cell activation. This suggests the presence of ongoing cycles of lesion and repair that could partially explain the maintenance of the structural properties of the muscle.