background Chronic obstructive pulmonary disease (COPD) is characterized by an incompletely reversible limitation in airflow. A physiological variable — the forced expiratory volume in one second (FEV 1 ) — is often used to grade the severity of COPD. However, patients with COPD have systemic manifestations that are not reflected by the FEV 1 . We hypothesized that a multidimensional grading system that assessed the respiratory and systemic expressions of COPD would better categorize and predict outcome in these patients. methods We first evaluated 207 patients and found that four factors predicted the risk of death in this cohort: the body-mass index (B), the degree of airflow obstruction (O) and dyspnea (D), and exercise capacity (E), measured by the six-minute–walk test. We used these variables to construct the BODE index, a multidimensional 10-point scale in which higher scores indicate a higher risk of death. We then prospectively validated the index in a cohort of 625 patients, with death from any cause and from respiratory causes as the outcome variables. results There were 25 deaths among the first 207 patients and 162 deaths (26 percent) in the validation cohort. Sixty-one percent of the deaths in the validation cohort were due to respiratory insufficiency, 14 percent to myocardial infarction, 12 percent to lung cancer, and 13 percent to other causes. Patients with higher BODE scores were at higher risk for death; the hazard ratio for death from any cause per one-point increase in the BODE score was 1.34 (95 percent confidence interval, 1.26 to 1.42; P<0.001), and the hazard ratio for death from respiratory causes was 1.62 (95 percent confidence interval, 1.48 to 1.77; P<0.001). The C statistic for the ability of the BODE index to predict the risk of death was larger than that for the FEV 1 (0.74 vs. 0.65).

https://www.taiss.com/gepoc/gecarp/gepubli/publdoc/026-026-cellibr-body-mass-index-airflow-obstruction-dyspnea.pdf

The Body-Mass Index, Airflow Obstruction, Dyspnea, and Exercise Capacity Index in Chronic Obstructive Pulmonary Disease

Background: Pulmonary rehabilitation is recognized as a core component of the management of individuals with chronic respiratory disease. Since the 2006 American Thoracic Society (ATS)/European Respiratory Society (ERS) Statement on Pulmonary Rehabilitation, there has been considerable growth in our knowledge of its efficacy and scope.

Purpose: The purpose of this Statement is to update the 2006 document, including a new definition of pulmonary rehabilitation and highlighting key concepts and major advances in the field.

Methods: A multidisciplinary committee of experts representing the ATS Pulmonary Rehabilitation Assembly and the ERS Scientific Group 01.02, “Rehabilitation and Chronic Care,” determined the overall scope of this update through group consensus. Focused literature reviews in key topic areas were conducted by committee members with relevant clinical and scientific expertise. The final content of this Statement was agreed on by all members.

Results: An updated definition of pulmonary rehabilitation is proposed. New data are presented on the science and application of pulmonary rehabilitation, including its effectiveness in acutely ill individuals with chronic obstructive pulmonary disease, and in individuals with other chronic respiratory diseases. The important role of pulmonary rehabilitation in chronic disease management is highlighted. In addition, the role of health behavior change in optimizing and maintaining benefits is discussed.

Conclusions: The considerable growth in the science and application of pulmonary rehabilitation since 2006 adds further support for its efficacy in a wide range of individuals with chronic respiratory disease

Read More: http://www.atsjournals.org/doi/abs/10.1164/rccm.201309-1634ST

/pdf/an-official-american-thoracic-society-european-respiratory-5fbz6s326i.pdf

An official American thoracic society/European respiratory society statement: Key concepts and advances in pulmonary rehabilitation

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterised by both an accelerated decline in lung function and periods of acute deterioration in symptoms termed exacerbations. The aim of this study was to investigate whether these are related. METHODS: Over 4 years, peak expiratory flow (PEF) and symptoms were measured at home daily by 109 patients with COPD (81 men; median (IQR) age 68.1 (63-74) years; arterial oxygen tension (PaO(2)) 9.00 (8.3-9.5) kPa, forced expiratory volume in 1 second (FEV(1)) 1.00 (0.7-1.3) l, forced vital capacity (FVC) 2.51 (1.9-3.0) l); of these, 32 (29 men) recorded daily FEV(1). Exacerbations were identified from symptoms and the effect of frequent or infrequent exacerbations (> or < 2.92 per year) on lung function decline was examined using cross sectional, random effects models. RESULTS: The 109 patients experienced 757 exacerbations. Patients with frequent exacerbations had a significantly faster decline in FEV(1) and peak expiratory flow (PEF) of -40.1 ml/year (n=16) and -2.9 l/min/year (n=46) than infrequent exacerbators in whom FEV(1) changed by -32.1 ml/year (n=16) and PEF by -0.7 l/min/year (n=63). Frequent exacerbators also had a greater decline in FEV(1) if allowance was made for smoking status. Patients with frequent exacerbations were more often admitted to hospital with longer length of stay. Frequent exacerbations were a consistent feature within a patient, with their number positively correlated (between years 1 and 2, 2 and 3, 3 and 4). CONCLUSIONS: These results suggest that the frequency of exacerbations contributes to long term decline in lung function of patients with moderate to severe COPD.

https://thorax.bmj.com/content/thoraxjnl/57/10/847.full.pdf

Relationship between exacerbation frequency and lung function decline in chronic obstructive pulmonary disease

Relationship between exacerbation frequency and lung function decline in chronic obstructive pulmonary disease (vol 57, pg 847, 2002)

Background: Patients with chronic obstructive pulmonary disease (COPD) often present with severe acute exacerbations requiring hospital treatment. However, little is known about the prognostic consequences of these exacerbations. A study was undertaken to investigate whether severe acute exacerbations of COPD exert a direct effect on mortality. 

Methods: Multivariate techniques were used to analyse the prognostic influence of acute exacerbations of COPD treated in hospital (visits to the emergency service and admissions), patient age, smoking, body mass index, co-morbidity, long term oxygen therapy, forced spirometric parameters, and arterial blood gas tensions in a prospective cohort of 304 men with COPD followed up for 5 years. The mean (SD) age of the patients was 71 (9) years and forced expiratory volume in 1 second was 46 (17)%. 

Results: Only older age (hazard ratio (HR) 5.28, 95% CI 1.75 to 15.93), arterial carbon dioxide tension (HR 1.07, 95% CI 1.02 to 1.12), and acute exacerbations of COPD were found to be independent indicators of a poor prognosis. The patients with the greatest mortality risk were those with three or more acute COPD exacerbations (HR 4.13, 95% CI 1.80 to 9.41). 

Conclusions: This study shows for the first time that severe acute exacerbations of COPD have an independent negative impact on patient prognosis. Mortality increases with the frequency of severe exacerbations, particularly if these require admission to hospital.

https://thorax.bmj.com/content/thoraxjnl/60/11/925.full.pdf

Severe acute exacerbations and mortality in patients with chronic obstructive pulmonary disease

Background: Exacerbations of chronic obstructive pulmonary disease (COPD) are a leading cause of admission to hospital among men in many countries, although the factors causing exacerbations are largely unknown. The association between readmission for a COPD exacerbation and a wide range of modifiable potential risk factors, after adjusting for sociodemographic and clinical factors, has been assessed. Methods: Three hundred and forty patients with COPD recruited during an admission for an exacerbation in four tertiary hospitals in the Barcelona area of Spain were followed for a mean period of 1.1 years. Information on potential risk factors, including clinical and functional status, medical care and prescriptions, medication adherence, lifestyle, health status, and social support, was collected at the recruitment admission. A Cox’s proportional hazards model was used to obtain independent relative risks of readmission for COPD. Results: During the follow up period 63% of patients were readmitted at least once, and 29% died. The final multivariate model showed the following risk (or protective) factors: ⩾3 admissions for COPD in the year before recruitment (hazard ratio (HR)=1.66, 95% CI 1.16 to 2.39), forced expiratory volume in 1 second (FEV 1 ) percentage predicted (0.97, 95% CI 0.96 to 0.99), oxygen tension (0.88, 95% CI 0.79 to 0.98), higher levels of usual physical activity (0.54, 95% CI 0.34 to 0.86), and taking anticholinergic drugs (1.81, 95% 1.11 to 2.94). Exposure to passive smoking was also related to an increased risk of readmission with COPD after adjustment for clinical factors (1.63, 95% CI 1.04 to 2.57) but did not remain in the final model. Conclusions: This is the first study to show a strong association between usual physical activity and reduced risk of readmission to hospital with COPD, which is potentially relevant for rehabilitation and other therapeutic strategies.

https://thorax.bmj.com/content/thoraxjnl/58/2/100.full.pdf

Risk factors of readmission to hospital for a COPD exacerbation: a prospective study

To assess whether generic and specific health-related quality of life (HRQL) are independently associated with total and specific mortality in patients with chronic obstructive pulmonary disease (COPD), we followed until 1999 a cohort of 321 male patients with COPD, recruited in 1993-1994 at outpatient respiratory clinics. Baseline characteristics recorded under stable clinical conditions included forced spirometry, arterial blood gas tensions, dyspnea scales, 11 comorbid conditions, St. George's Respiratory Questionnaire (SGRQ), and SF-36 Health Survey. Vital status was assessed through reinterviews, the Mortality Register, and clinical records. Subjects who died (106) were older (69.8 versus 62.5 years) (p < 0.001), had lower body mass index (BMI) (25.4 versus 27.1) (p < 0.01), were more impaired in the clinical characteristics studied (%FEV(1), 34.0 versus 51.0) (p < 0.001), and had long-term oxygen therapy more frequently (31% versus 7%) (p < 0.001). Survival was shorter when worse HRQL was reported. SGRQ total and SF-36 physical summary scores were independently associated with total and respiratory mortality in Cox models, including age, FEV(1), and BMI. The total mortality-standardized hazard ratios for both HRQL measures were 1.3, whereas those for FEV(1) were 1.6. HRQL measures provide independent and relevant information on the health status of male patients with COPD. Their use should be considered for a more thorough evaluation and staging of patients with COPD.

/pdf/health-related-quality-of-life-and-mortality-in-male-3zolz62gxp.pdf

Health-related Quality of Life and Mortality in Male Patients with Chronic Obstructive Pulmonary Disease

Although exacerbation of chronic obstructive pulmonary disease (COPD) is important in terms of health and costs, there is little information about which are the risk factors. We estimated the association between modifiable and nonmodifiable potential risk factors of exacerbation and the admission for a COPD exacerbation, using a case-control approach. Cases were recruited among admissions for COPD exacerbation during 1 yr in four tertiary hospitals of the Barcelona area. Control subjects were recruited from hospital's register of discharges, having coincided with the referent case in a previous COPD admission but being clinically stable when the referent case was hospitalized. All patients completed a questionnaire and performed spirometry, blood gases, and physical examination. Information about potential risk factors was collected, including variables related to clinical status, characteristics of medical care, medical prescriptions, adherence to medication, lifestyle, quality of life, and social support. A total of 86 cases and 86 control subjects were included, mean age 69 yr, mean FEV(1) 39% of predicted. Multivariate logistic regression showed the following risk (or protective) factors of COPD hospitalization: three or more COPD admissions in the previous year (odds ratio [OR] 6.21, p = 0.008); FEV(1) (OR 0.96 per percentual unit, p < 0.0005); underprescription of long-term oxygen therapy (LTOT) (OR 22.64, p = 0.007); and current smoking (OR 0.30, p = 0.022). Among a wide range of potential risk factors we have found that only previous admissions, lower FEV(1), and underprescription of LTOT are independently associated with a higher risk of admission for a COPD exacerbation.

https://www.atsjournals.org/doi/pdf/10.1164/ajrccm.164.6.2006012

Risk factors for hospitalization for a chronic obstructive pulmonary disease exacerbation. EFRAM study.

Nasal prongs (NP) connected to a pressure transducer have been suggested as a useful alternative for measuring nasal flow in sleep apnea/hypopnea patients However, flow measured with NP is expected to be nonlinear The aim of the present study was to analyze and correct the nonlinearity of nasal flow measurements with NP (VNP) Nasal flow was simultaneously measured with a pneumotachograph (PNT; V) and (NP; VNP) in six healthy subjects during 60 s of breathing at different tidal volumes Nonlinearity of VNP was assessed by fitting separately, for inspiration and expiration, a Rorher-model equation (VNP x K1 x V + K2 x V2) In addition, we fitted the data to a simpler nonlinear quadratic model (P = K x V2) The main findings were: (1) an excellent fit of the Rorher equation to measured data in all cases; (2) although differences in the Rorher equation coefficients between inspiration and expiration were observed, they were not statistically significant; (3) a substantial intersubject variability was found; and finally, (4) the square root of VNP acceptably fitted the nasal flow data measured by PNT (V) in most cases We conclude that in order to quantitatively assess nasal flow with NP, data should be corrected for their nonlinear pressure-flow relationships and, that the square root of the flow signal measured with NP is the simplest method of correcting for the observed nonlinearity

Evaluation of nasal prongs for estimating nasal flow.

Background:Patients with chronic obstructive pulmonary disease (COPD) have a limited exercise capacity. Surprisingly, little is known about their levels of physical activity practice. We assessed the levels and determinants of physical activity practice in severe COPD patients.Methods:A cros

M A Félez

Papers

Risk factors of readmission to hospital for a COPD exacerbation: a prospective study

Health-related Quality of Life and Mortality in Male Patients with Chronic Obstructive Pulmonary Disease

Risk factors for hospitalization for a chronic obstructive pulmonary disease exacerbation. EFRAM study.

Evaluation of nasal prongs for estimating nasal flow.

Physical activity and its determinants in severe chronic obstructive pulmonary disease.