Randomized Trial of Nocturnal Oxygen in Chronic Obstructive Pulmonary Disease.

BACKGROUND: Long-term oxygen therapy improves survival in patients with chronic obstructive pulmonary disease (COPD) and chronic severe daytime hypoxemia. However, the efficacy of oxygen therapy for the management of isolated nocturnal hypoxemia is uncertain. METHODS: We designed this double-blind, placebo-controlled, randomized trial to determine, in patients with COPD who have nocturnal arterial oxygen desaturation without qualifying for long-term oxygen therapy, whether nocturnal oxygen provided for a period of 3 to 4 years would decrease mortality or the worsening of disease such that patients meet current specifications for long-term oxygen therapy. Patients with an oxygen saturation of less than 90% for at least 30% of the recording time on nocturnal oximetry were assigned, in a 1:1 ratio, to receive either nocturnal oxygen or ambient air from a sham concentrator (placebo). The primary outcome was a composite of death from any cause or a requirement for long-term oxygen therapy as defined by the Nocturnal Oxygen Therapy Trial (NOTT) criteria in the intention-to-treat population. RESULTS: Recruitment was stopped prematurely because of recruitment and retention difficulties after 243 patients, of a projected 600, had undergone randomization at 28 centers. At 3 years of follow-up, 39.0% of the patients assigned to nocturnal oxygen (48 of 123) and 42.0% of those assigned to placebo (50 of 119) met the NOTT-defined criteria for long-term oxygen therapy or had died (difference, -3.0 percentage points; 95% confidence interval, -15.1 to 9.1). CONCLUSIONS: Our underpowered trial provides no indication that nocturnal oxygen has a positive or negative effect on survival or progression to long-term oxygen therapy in patients with COPD. (Funded by the Canadian Institutes of Health Research; INOX ClinicalTrials.gov number, NCT01044628.).

Early Desaturation During 6-Minute Walk Test is a Predictor of Mortality in COPD.

BACKGROUND: Oxygen desaturation during exercise is mainly observed in severe cases of chronic obstructive pulmonary disease (COPD) and is associated with a worse prognosis, but little is known about the type of desaturation that causes the greatest risk of mortality. MATERIAL AND METHODS: We studied all of the 6-min walk tests performed periodically at a tertiary hospital over a period of 12 years in patients with moderate or severe COPD. We classified patients as non-desaturators if they did not suffer a drop in oxygen saturation (SpO2 < 88%) during the test, early desaturators if the time until desaturation was < 1 min, and non-early desaturators if it was longer than 1 min. The average length of follow-up per patient was 5.6 years. RESULTS: Of the 319 patients analyzed, 126 non-desaturators, 91 non-early desaturators and 102 early desaturators were identified. The mortality analysis showed that early desaturators had a mortality of 73%, while it was 38% for non-early desaturators and 28% for non-desaturators, with a survival of 5.9 years compared to 7.5 years and 9.6 years, respectively (hazard ratio of 3.50; 95% CI 2.3-5.3; p < 0.0001). CONCLUSIONS: The early desaturation seen in patients with chronic obstructive pulmonary disease is associated with greater mortality and is likely responsible for the poor prognosis shown globally in patients who desaturate. The survival of patients with early desaturation is almost 4 years less with respect to non-desaturators, and they, thus, require closer observation.

Trajectories of Severe Exacerbations of Chronic Obstructive Pulmonary Disease and Their Relationship with Mortality Risk.

PURPOSE: Acute exacerbations of COPD (AECOPD) are important factors contributing to mortality risk. The rate of exacerbations varies overtime. An inconsistent pattern of exacerbation occurrence is a common finding. The mortality risk associated with such a pattern is not entirely clear. Our objective was to assess the risk of mortality associated with various possible patterns of AECOPD trajectories. METHODS: This is a multicenter historical cohort study. Four different exacerbation trajectories were defined according to the incidence of severe AECOPD requiring hospital admission 2 years before and after the date of the first visit to the respiratory clinic-Consistent non-exacerbators (NEx): no AECOPD before or after the index date; consistent exacerbators (Ex): at least one AECOPD both before and after the index date; converters to exacerbators (CONV-Ex): no exacerbations before and at least one AECOPD after the index date; converters to non-exacerbators (CONV-NEx): at least one AECOPD before the index date, and no exacerbations after said date. All-cause mortality risk for these trajectories was assessed. RESULTS: A total of 1713 subjects were included in the study: NEx: 1219 (71.2%), CONV-NEx: 225 (13.1%), CONV-Ex: 148 (8.6%), Ex: 121 (7.1%). After correcting for confounding variables, the group with the highest mortality risk was Ex. The CONV-Ex and CONV-Nex groups had a mortality risk between Ex and NEx, with no significant differences between them. CONCLUSION: Different possible trajectories of severe AECOPD before and after a first specialized consultation are associated with different mortality risks. An inconsistent pattern of exacerbations has a mortality risk between Ex and NEx, with no clear differences between CONV-Ex and CONV-NEx.

Predictive factors over time of health-related quality of life in COPD patients.

BACKGROUND: Health-related quality of life (HRQoL) should be seen as a tool that provides an overall view of the general clinical condition of a COPD patient. The aims of this study were to identify variables associated with HRQoL and whether they continue to have an influence in the medium term, during follow-up. METHODS: Overall, 543 patients with COPD were included in this prospective observational longitudinal study. At all four visits during a 5-year follow-up, the patients completed the Saint George's Respiratory Questionnaire (SGRQ), pulmonary function tests, the 6-min walk test (6MWT), and a physical activity (PA) questionnaire, among others measurements. Data on hospitalization for COPD exacerbations and comorbidities were retrieved from the personal electronic clinical record of each patient at every visit. RESULTS: The best fit to the data of the cohort was obtained with a beta-binomial distribution. The following variables were related over time to SGRQ components: age, inhaled medication, smoking habit, forced expiratory volume in one second, handgrip strength, 6MWT distance, body mass index, residual volume, diffusing capacity of the lung for carbon monoxide, PA (depending on level, 13 to 35% better HRQoL, in activity and impacts components), and hospitalizations (5 to 45% poorer HRQoL, depending on the component). CONCLUSIONS: Among COPD patients, HRQoL was associated with the same variables throughout the study period (5-year follow-up), and the variables with the strongest influence were PA and hospitalizations.

External Validation and Recalculation of the CODEX Index in COPD Patients. A 3CIAplus Cohort Study.

The CODEX index was developed and validated in patients hospitalized for COPD exacerbation to predict the risk of death and readmission within one year after discharge. Our study aimed to validate the CODEX index in a large external population of COPD patients with variable durations of follow-up. Additionally, we aimed to recalculate the thresholds of the CODEX index using the cutoffs of variables previously suggested in the 3CIA study (mCODEX). Individual data on 2,755 patients included in the COPD Cohorts Collaborative International Assessment Plus (3CIA+) were explored. A further two cohorts (ESMI AND EGARPOC-2) were added. To validate the CODEX index, the relationship between mortality and the CODEX index was assessed using cumulative/dynamic ROC curves at different follow-up periods, ranging from 3 months up to 10 years. Calibration was performed using univariate and multivariate Cox proportional hazard models and Hosmer-Lemeshow test. A total of 3,321 (87.8% males) patients were included with a mean ± SD age of 66.9 ± 10.5 years, and a median follow-up of 1,064 days (IQR 25-75% 426-1643), totaling 11,190 person-years. The CODEX index was statistically associated with mortality in the short- (≤3 months), medium- (≤1 year) and long-term (10 years), with an area under the curve of 0.72, 0.70 and 0.76, respectively. The mCODEX index performed better in the medium-term (<1 year) than the original CODEX, and similarly in the long-term. In conclusion, CODEX and mCODEX index are good predictors of mortality in patients with COPD, regardless of disease severity or duration of follow-up.

Predictors of one-year mortality after hospitalization for an exacerbation of COPD.

BACKGROUND: Hospitalization for a severe exacerbation of COPD (eCOPD) is an important event in the natural history of COPD. Identifying factors related to mortality 1 year after hospitalization could help determine interventions to reduce mortality. METHODS: In a prospective, observational, multicentre study, we evaluated data from two cohorts: the Spanish audit of hospital COPD exacerbation care (our derivation sample) and the Spanish cohort of the European audit of COPD exacerbation care (our validation sample). The endpoint was all-cause mortality. Mortality was determined by local research managers of the participating hospitals and matched the official national index records in Spain. RESULTS: In the multivariate analysis, factors independently related to an increase in mortality were older age, cardio-cerebro-vascular and/or dementia comorbidities, PaCO2 > 55 mmHg measured at emergency department arrival, hospitalizations for COPD exacerbations in the previous year, and hospital characteristics. The area under the receiver-operating curve for this model was 0.75 in the derivation cohort and 0.76 in the validation cohort. CONCLUSION: One-year mortality following the index hospitalization for an exacerbation of COPD was related to clinical characteristics of the patient and of the index event, previous events of similar severity, and characteristics of the hospital where the patient was treated.

Multi-level differential network analysis of COPD exacerbations.

Patients with chronic obstructive pulmonary disease (COPD) often suffer episodes of exacerbation (ECOPD) that impact negatively the course of their disease. ECOPD are heterogeneous events of unclear pathobiology and non-specific diagnosis. Network analysis is a novel research approach that can help unravelling complex biological systems. We hypothesised that the comparison of multi-level (i.e., clinical, physiological, biological, imaging and microbiological) correlation networks determined during ECOPD and convalescence can yield novel patho-biologic information.In this proof-of-concept study we included 86 patients hospitalised because of ECOPD in a multicentre study in Spain. Patients were extensively characterised both during the first 72 h of hospitalisation and during clinical stability, at least 3 months after hospital discharge.We found that 1) episodes of ECOPD are characterised by disruption of the network correlation observed during convalescence; and 2) a panel of biomarkers that include increased levels of dyspnoea, circulating neutrophils and C-reactive protein (CRP) has a high predictive value for ECOPD diagnosis (AUC 0.97).We conclude that ECOPD 1) are characterised by disruption of network homeokinesis that exists during convalescence; and 2) can be identified objectively by using a panel of three biomarkers (dyspnoea, circulating neutrophils and CRP levels) frequently determined in clinical practice.

A simple algorithm for the identification of clinical COPD phenotypes.

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.

A proposal for the withdrawal of inhaled corticosteroids in the clinical practice of chronic obstructive pulmonary disease.

According to the current clinical practice guidelines for chronic obstructive pulmonary disease (COPD), the addition of inhaled corticosteroids (ICS) to long-acting ß2 agonist therapy is recommended in patients with moderate-to-severe disease and an increased risk of exacerbations. However, ICS are largely overprescribed in clinical practice, and most patients are unlikely to benefit from long-term ICS therapy.Evidence from recent randomized-controlled trials supports the hypothesis that ICS can be safely and effectively discontinued in patients with stable COPD and in whom ICS therapy may not be indicated, without detrimental effects on lung function, health status, or risk of exacerbations. This article summarizes the evidence supporting the discontinuation of ICS therapy, and proposes an algorithm for the implementation of ICS withdrawal in patients with COPD in clinical practice.Given the increased risk of potentially serious adverse effects and complications with ICS therapy (including pneumonia), the use of ICS should be limited to the minority of patients in whom the treatment effects outweigh the risks.

Prognostic assessment in COPD without lung function: the B-AE-D indices.

Several composite markers have been proposed for risk assessment in chronic obstructive pulmonary disease (COPD). However, choice of parameters and score complexity restrict clinical applicability. Our aim was to provide and validate a simplified COPD risk index independent of lung function.The PROMISE study (n=530) was used to develop a novel prognostic index. Index performance was assessed regarding 2-year COPD-related mortality and all-cause mortality. External validity was tested in stable and exacerbated COPD patients in the ProCOLD, COCOMICS and COMIC cohorts (total n=2988).Using a mixed clinical and statistical approach, body mass index (B), severe acute exacerbations of COPD frequency (AE), modified Medical Research Council dyspnoea severity (D) and copeptin (C) were identified as the most suitable simplified marker combination. 0, 1 or 2 points were assigned to each parameter and totalled to B-AE-D or B-AE-D-C. It was observed that B-AE-D and B-AE-D-C were at least as good as BODE (body mass index, airflow obstruction, dyspnoea, exercise capacity), ADO (age, dyspnoea, airflow obstruction) and DOSE (dyspnoea, obstruction, smoking, exacerbation) indices for predicting 2-year all-cause mortality (c-statistic: 0.74, 0.77, 0.69, 0.72 and 0.63, respectively; Hosmer-Lemeshow test all p>0.05). Both indices were COPD specific (c-statistic for predicting COPD-related 2-year mortality: 0.87 and 0.89, respectively). External validation of B-AE-D was performed in COCOMICS and COMIC (c-statistic for 1-year all-cause mortality: 0.68 and 0.74; c-statistic for 2-year all-cause mortality: 0.65 and 0.67; Hosmer-Lemeshow test all p>0.05).The B-AE-D index, plus copeptin if available, allows a simple and accurate assessment of COPD-related risk.

Noninvasive ventilation for severely acidotic patients in respiratory intermediate care units : Precision medicine in intermediate care units.

BACKGROUND: Severe acidosis can cause noninvasive ventilation (NIV) failure in chronic obstructive pulmonary disease (COPD) patients with acute hypercapnic respiratory failure (AHRF). NIV is therefore contraindicated outside of intensive care units (ICUs) in these patients. Less is known about NIV failure in patients with acute cardiogenic pulmonary edema (ACPE) and obesity hypoventilation syndrome (OHS). Therefore, the objective of the present study was to compare NIV failure rates between patients with severe and non-severe acidosis admitted to a respiratory intermediate care unit (RICU) with AHRF resulting from ACPE, COPD or OHS. METHODS: We prospectively included acidotic patients admitted to seven RICUs, where they were provided NIV as an initial ventilatory support measure. The clinical characteristics, pH evolutions, hospitalization or RICU stay durations and NIV failure rates were compared between patients with a pH ≥ 7.25 and a pH < 7.25. Logistic regression analysis was performed to determine the independent risk factors contributing to NIV failure. RESULTS: We included 969 patients (240 with ACPE, 540 with COPD and 189 with OHS). The baseline rates of severe acidosis were similar among the groups (45 % in the ACPE group, 41 % in the COPD group, and 38 % in the OHS group). Most of the patients with severe acidosis had increased disease severity compared with those with non-severe acidosis: the APACHE II scores were 21 ± 7.2 and 19 ± 5.8 for the ACPE patients (p < 0.05), 20 ± 5.7 and 19 ± 5.1 for the COPD patients (p < 0.01) and 18 ± 5.9 and 17 ± 4.7 for the OHS patients, respectively (NS). The patients with severe acidosis also exhibited worse arterial blood gas parameters: the PaCO2 levels were 87 ± 22 and 70 ± 15 in the ACPE patients (p < 0.001), 87 ± 21 and 76 ± 14 in the COPD patients, and 83 ± 17 and 74 ± 14 in the OHS patients (NS)., respectively Further, the patients with severe acidosis required a longer duration to achieve pH normalization than those with non-severe acidosis (patients with a normalized pH after the first hour: ACPE, 8 % vs. 43 %, p < 0.001; COPD, 11 % vs. 43 %, p < 0.001; and OHS, 13 % vs. 51 %, p < 0.001), and they had longer RICU stays, particularly those in the COPD group (ACPE, 4 ± 3.1 vs. 3.6 ± 2.5, NS; COPD, 5.1 ± 3 vs. 3.6 ± 2.1, p < 0.001; and OHS, 4.3 ± 2.6 vs. 3.7 ± 3.2, NS). The NIV failure rates were similar between the patients with severe and non-severe acidosis in the three disease groups (ACPE, 16 % vs. 12 %; COPD, 7 % vs. 7 %; and OHS, 11 % vs. 4 %). No common predictive factor for NIV failure was identified among the groups. CONCLUSIONS: ACPE, COPD and OHS patients with AHRF and severe acidosis (pH ≤ 7.25) who are admitted to an RICU can be successfully treated with NIV in these units. These results may be used to determine precise RICU admission criteria.

Predictors of Change in Dyspnea Level in Acute Exacerbations of COPD.

The aim of this study was to identify factors related to changes in dyspnoea level in the acute and short-term periods after acute exacerbation of chronic obstructive pulmonary disease. This was a prospective cohort study of patients with symptoms of acute chronic obstructive pulmonary disease exacerbation who attended one of 17 hospitals in Spain between June 2008 and September 2010. Clinical data and patient reported measures (dyspnoea level, health-related quality of life, anxiety and depression levels, capacity to perform physical activity) were collected from arrival to the emergency department up to a week after the visit in discharged patients and to discharge in admitted patients (short term). Main outcomes were time course of dyspnoea over the acute (first 24 hours) and short-term periods, mortality and readmission within 2 months of the index episode. Changes in dyspnoea in both periods were related capacity to perform physical activity as well as clinical variables. Short-term changes in dyspnoea were also related to dyspnoea at 24 hours after the ED visit, and anxiety and depression levels. Dyspnoea worsening or failing to improve over the studied periods was associated with poor clinical outcomes. Patient-reported measures are predictive of changes in dyspnoea level.

One-year Mortality in COPD After an Exacerbation: The Effect of Physical Activity Changes During the Event.

Mortality is one of the most important outcomes in patients with chronic obstructive pulmonary disease (COPD). Different predictors have been associated with mortality, including the patient's level of physical activity (PA). The objective of this work was to establish the relationship between changes in PA during a moderate-to-severe COPD exacerbation (eCOPD) and 1-year mortality after the index event. This was a prospective observational cohort study with recruitment of 2,484 patients with an eCOPD attending the emergency department (ED) of 16 participating hospitals. Variables recorded included clinical and sociodemographic data from medical records, dyspnea, health-related quality of life, and PA before the index eCOPD and 2 months after the hospital or ED discharge, as reported by the patient. In the multivariate analysis worsening changes in PA from baseline to 2 months after the ED index visit [odds ratio (ORs) from 2.78 to 6.31] was related to 1-year mortality, using the age-adjusted Charlson comorbidity index (OR: 1.22), and previous use of long-term domiciliary oxygen therapy or non-invasive mechanical ventilation at home (OR: 1.68). The same variables were also predictive in the validation sample. Areas under the receiver operating characteristic curve in the derivation and validation sample were 0.79 and 0.78, respectively. In conclusion, PA is the strongest predictor of dying in the following year, i.e., those with worsened PA from baseline to 2 months after an eCOPD or with very low PA levels have a higher risk.

A decision tree to assess short-term mortality after an emergency department visit for an exacerbation of COPD: a cohort study.

BACKGROUND: Creating an easy-to-use instrument to identify predictors of short-term (30/60-day) mortality after an exacerbation of chronic obstructive pulmonary disease (eCOPD) could help clinicians choose specific measures of medical care to decrease mortality in these patients. The objective of this study was to develop and validate a classification and regression tree (CART) to predict short term mortality among patients evaluated in an emergency department (ED) for an eCOPD. METHODS: We conducted a prospective cohort study including participants from 16 hospitals in Spain. COPD patients with an exacerbation attending the emergency department (ED) of any of the hospitals between June 2008 and September 2010 were recruited. Patients were randomly divided into derivation (50%) and validation samples (50%). A CART based on a recursive partitioning algorithm was created in the derivation sample and applied to the validation sample. RESULTS: Two thousand four hundred eighty-seven patients, 1252 patients in the derivation sample and 1235 in the validation sample, were enrolled in the study. Based on the results of the univariate analysis, five variables (baseline dyspnea, cardiac disease, the presence of paradoxical breathing or use of accessory inspiratory muscles, age, and Glasgow Coma Scale score) were used to build the CART. Mortality rates 30 days after discharge ranged from 0% to 55% in the five CART classes. The lowest mortality rate was for the branch composed of low baseline dyspnea and lack of cardiac disease. The highest mortality rate was in the branch with the highest baseline dyspnea level, use of accessory inspiratory muscles or paradoxical breathing upon ED arrival, and Glasgow score <15. The area under the receiver-operating curve (AUC) in the derivation sample was 0.835 (95% CI: 0.783, 0.888) and 0.794 (95% CI: 0.723, 0.865) in the validation sample. CART was improved to predict 60-days mortality risk by adding the Charlson Comorbidity Index, reaching an AUC in the derivation sample of 0.817 (95% CI: 0.776, 0.859) and 0.770 (95% CI: 0.716, 0.823) in the validation sample. CONCLUSIONS: We identified several easy-to-determine variables that allow clinicians to classify eCOPD patients by short term mortality risk, which can provide useful information for establishing appropriate clinical care. TRIAL REGISTRATION: NCT02434536.

Predictors of Hospital Length of Stay in Patients with Exacerbations of COPD: A Cohort Study.

BACKGROUND: Various studies have tried to delimit the predictors of hospital length of stay (LOS) for patients with exacerbated chronic obstructive pulmonary disease (eCOPD), but have been disadvantaged by certain limiting factors. OBJECTIVE: Our goal was to prospectively identify predictors of LOS in these patients and to validate our results. DESIGN: This was a prospective cohort study. PARTICIPANTS: Subjects were patients with eCOPD who visited 16 hospital emergency departments (EDs) and who were admitted to the hospital. MAIN MEASURES: Data were recorded on possible predictor variables at the ED visit, on admission and 24 hours later, during hospitalization, and on discharge. LOS and prolonged LOS (≥ 9 days, considering the 75th percentile of LOS in our sample) were the outcomes of interest. Multivariate multilevel linear and logistic regression models were employed. RESULTS: A total of 1,453 patients were equally divided between derivation and validation samples. The hospital variable was the best predictor of LOS. Multivariate predictors of LOS, as log-transformed variables, were the hospital, baseline dyspnea and physical activity levels and fatigue at 24 hours, intensive care or intensive respiratory care unit admission, the need for antibiotics, and complications during hospitalization. Predictors of prolonged LOS were also the hospital, baseline dyspnea and fatigue at 24 hours, ICU or IRCU admission, and complications during hospitalization (AUC: 0.77). Models were validated in the validation sample (AUC: 0.75). CONCLUSIONS: We identified a number of modifiable factors, including baseline dyspnea, physical activity level, and hospital variability, that influenced the LOS of patients with eCOPD who were admitted to the hospital.

The Use of Pulse Oximetry to Determine Hypoxemia in Acute Exacerbations of COPD.

BACKGROUND: There is little evidence that the guideline-recommended oxygen saturation of 92% is the best cut-off point for detecting hypoxemia in COPD exacerbations. OBJECTIVE: To detect and validate pulse oximetry oxygen saturation cut-off values likely to detect hypoxemia in patients with aeCOPD, to explore the correlation between oxygen saturation measured by pulse oximetry and hypoxemia or hypercapnic respiratory failure. METHODOLOGY: Cross-sectional study nested in the IRYSS-COPD study with 2,181 episodes of aeCOPD recruited between 2008 and 2010 in 16 hospitals belonging to the Spanish Public Health System. Data collected include determination of oxygen saturation by pulse oximetry upon arrival in the emergency department (ED), first arterial blood gasometry values, sociodemographic information, background medical history and clinical variables upon ED arrival. Logistic regression models were performed using as the dependent variables hypoxemia (PaO2 < 60 mmHg) and hypercapnic respiratory failure (PaO2 < 60 mmHg and PaCO2 > 45). Optimal cut-off points were calculated. RESULTS: The correlation coefficient between oxygen saturation and pO2 measured by arterial blood gasometry was 0.89. The area under the curve (AUC) for the hypoxemia model was 0.97 (0.96-0.98) and the optimal cut-off point for hypoxemia was an oxygen saturation of 90%. The AUC for hypercapnic respiratory failure was 0.90 (0.87-0.92) and the optimal cut-off point was an oxygen saturation of 88%. CONCLUSIONS: Our results support current recommendations for ordering blood gasometry based on pulse oximetry oxygen saturation cut-offs for hypoxemia. We also provide easy to use formulae to calculate pO2 from oxygen saturation measured by pulse oximetry.

Predictive score for mortality in patients with COPD exacerbations attending hospital emergency departments.

BACKGROUND: Limited information is available about predictors of short-term outcomes in patients with exacerbation of chronic obstructive pulmonary disease (eCOPD) attending an emergency department (ED). Such information could help stratify these patients and guide medical decision-making. The aim of this study was to develop a clinical prediction rule for short-term mortality during hospital admission or within a week after the index ED visit. METHODS: This was a prospective cohort study of patients with eCOPD attending the EDs of 16 participating hospitals. Recruitment started in June 2008 and ended in September 2010. Information on possible predictor variables was recorded during the time the patient was evaluated in the ED, at the time a decision was made to admit the patient to the hospital or discharge home, and during follow-up. Main short-term outcomes were death during hospital admission or within 1 week of discharge to home from the ED, as well as at death within 1 month of the index ED visit. Multivariate logistic regression models were developed in a derivation sample and validated in a validation sample. The score was compared with other published prediction rules for patients with stable COPD. RESULTS: In total, 2,487 patients were included in the study. Predictors of death during hospital admission, or within 1 week of discharge to home from the ED were patient age, baseline dyspnea, previous need for long-term home oxygen therapy or non-invasive mechanical ventilation, altered mental status, and use of inspiratory accessory muscles or paradoxical breathing upon ED arrival (area under the curve (AUC) = 0.85). Addition of arterial blood gas parameters (oxygen and carbon dioxide partial pressures (PO2 and PCO2)) and pH) did not improve the model. The same variables were predictors of death at 1 month (AUC = 0.85). Compared with other commonly used tools for predicting the severity of COPD in stable patients, our rule was significantly better. CONCLUSIONS: Five clinical predictors easily available in the ED, and also in the primary care setting, can be used to create a simple and easily obtained score that allows clinicians to stratify patients with eCOPD upon ED arrival and guide the medical decision-making process.

An official European Respiratory Society statement on physical activity in COPD.

This European Respiratory Society (ERS) statement provides a comprehensive overview on physical activity in patients with chronic obstructive pulmonary disease (COPD). A multidisciplinary Task Force of experts representing the ERS Scientific Group 01.02 "Rehabilitation and Chronic Care" determined the overall scope of this statement through consensus. Focused literature reviews were conducted in key topic areas and the final content of this Statement was agreed upon by all members. The current knowledge regarding physical activity in COPD is presented, including the definition of physical activity, the consequences of physical inactivity on lung function decline and COPD incidence, physical activity assessment, prevalence of physical inactivity in COPD, clinical correlates of physical activity, effects of physical inactivity on hospitalisations and mortality, and treatment strategies to improve physical activity in patients with COPD. This Task Force identified multiple major areas of research that need to be addressed further in the coming years. These include, but are not limited to, the disease-modifying potential of increased physical activity, and to further understand how improvements in exercise capacity, dyspnoea and self-efficacy following interventions may translate into increased physical activity. The Task Force recommends that this ERS statement should be reviewed periodically (e.g. every 5-8 years).

Influence of changes in physical activity on frequency of hospitalization in chronic obstructive pulmonary disease.

BACKGROUND AND OBJECTIVE: To evaluate whether changes in regular physical activity (PA) in patients with chronic obstructive pulmonary disease (COPD) affect the rate of hospitalizations for COPD exacerbation (eCOPD). METHODS: Five hundred forty-three ambulatory clinic patients being treated for COPD were prospectively identified. PA was self-reported by patients, and the level was established by the distance they walked (km/day) at least 3 days per week. Hospitalizations were recorded from hospital databases. All patients with at least a 2-year follow-up after enrollment were included in the analysis. The response variable was the number of hospitalizations for eCOPD within the 3-year period from 2 to 5 years after study enrollment. RESULTS: Three hundred ninety-one survivors were studied. Mean forced expiratory volume in 1 s was 52% (±14%) of the predicted value. Patients who maintained a lower level of PA had an increased rate of hospitalization (odds ratio 1.901; 95% confidence interval 1.090-3.317). After having had the highest level of PA, those patients who decreased their PA in the follow-up showed an increasing rate of hospitalizations (odds ratio 2.134; 95% confidence interval 1.146-3.977). CONCLUSIONS: Patients with COPD with a low level of PA or who reduced their PA over time were more likely to experience a significant increase in the rate of hospitalization for eCOPD. Changes to a higher level of PA or maintaining a moderate or high level of PA over time, with a low intensity activity such as walking for at least 3-6 km/day, could reduce the rate of hospitalizations for eCOPD.