Background: Prognosis in chronic obstructive pulmonary disease (COPD) is poorly predicted by indices of air flow obstruction, because other factors that reflect the systemic nature of the disease also influence prognosis. Objective: To test the hypothesis that a reduction in quadriceps maximal voluntary contraction force (QMVC) is a useful predictor of mortality in patients with COPD. Methods: A mortality questionnaire was sent to the primary care physician of 184 patients with COPD who had undergone quadriceps strength measurement over the past 5 years. QMVC was expressed as a percentage of the patient's body mass index. The end point measured was death or lung transplantation, and median (range) follow-up was 38 (1-54) months. Results: Data were obtained for 162 patients (108 men and 54 women) with a mean (SD) percentage of forced expiratory volume in 1 s (FEV 1 ) predicted of 35.6 (16.2), giving a response rate of 88%. Transplantfree survival of the cohort was 93.5% at 1 year and 87.1% at 2 years. Cox regression models showed that the mortality risk increased with increasing age and with reducing QMVC. Only age (HR 1.72 (95% CI 1.14 to 2.6); p = 0.01) and QMVC (HR 0.91 (95% CI 0.83 to 0.99); p = 0.036) continued to be significant predictors of mortality when controlled for other variables in the multivariate analysis. Conclusion: QMVC is simple and provides more powerful prognostic information on COPD than that provided by age, body mass index and forced expiratory volume in 1 s. C hronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the world, 1 but prognosis is only poorly predicted by indices of air flow obstruction. Given this limitation, a new severity classification, the Body Mass Index, Airflow Obstruction, Dyspnoea and Exercise Capacity (BODE) Index, 2 has been proposed that takes into account the multicomponent nature of COPD with considerable emphasis being placed on the body mass index (BMI) as an indicator of poor prognosis.3-6 However, many investigators consider that it is, more specifically, the loss of skeletal muscle mass which confers a poorer prognosis in patients with COPD. 7-10Muscle mass depletion is associated with reduced exercise performance, 11 12 increased dyspnoea 13 and worse health-related quality of life.14 Similarly, skeletal muscle weakness is a common finding in COPD and is associated with reduced exercise capacity. [15][16][17] As exercise capacity is thought to be an important factor in determining mortality in COPD, 18 it perhaps follows that muscle weakness should also predict mortality.In a recent paper by Marquis et al, 7 CT scanning was used to measure the mid-thigh cross-sectional area (MTCSA CT ) in patients with COPD. This radiological measure of quadriceps bulk was shown to predict mortality better than BMI, and this was particularly so in patients with more severe COPD (forced expiratory volume in 1 s, (FEV 1 ) ,50%). This measure is attractive as a single reproducible predictor of mortality from COPD, but some obvious drawbacks limi...

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Quadriceps strength relates to exercise capacity and prognosis in chronic obstructive pulmonary disease (COPD). We wanted to quantify the prevalence of quadriceps weakness in COPD and hypothesised that it would not be restricted to patients with severe airflow obstruction or dyspnoea.Predicted quadriceps strength was calculated using a regression equation (incorporating age, sex, height and fat-free mass), based on measurements from 212 healthy subjects. The prevalence of weakness (defined as observed values 1.645 standardised residuals below predicted) was related to Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage and Medical Research Council (MRC) dyspnoea score in two cohorts of stable COPD outpatients recruited from the UK (n5240) and the Netherlands (n5351).32% and 33% of UK and Dutch COPD patients had quadriceps weakness. A significant proportion of patients in GOLD stages 1 and 2, or with an MRC dyspnoea score of 1 or 2, had quadriceps weakness (28 and 26%, respectively). These values rose to 38% in GOLD stage 4, and 43% in patients with an MRC Score of 4 or 5.Quadriceps weakness was demonstrable in one-third of COPD patients attending hospital respiratory outpatient services. Quadriceps weakness exists in the absence of severe airflow obstruction or breathlessness.

Background Exacerbations of chronic obstructive pulmonary disease (COPD) are characterised by increased dyspnoea, reduced quality of life and muscle weakness. Re-exacerbation and hospital admission are common. Pulmonary rehabilitation (PR) administered after hospital admission for an exacerbation can improve quality of life and exercise capacity. Objective To determine whether outpatient postexacerbation PR (PEPR) could reduce subsequent hospital admission episodes. Methods Patients admitted to hospital for an exacerbation of COPD were randomised to receive either usual follow-up care (UC) or PEPR after discharge. Hospital admission and emergency department attendances for COPD exacerbations were recorded over a 3-month period and analysed on an intention-to-treat basis. Secondary outcomes included exercise capacity and quadriceps strength. Results 60 patients underwent concealed randomisation at the time of their hospital discharge (UC: n¼30, mean (SD) age 65 (10) years, forced expiratory volume in 1 s (FEV 1 ) 52 (22)% predicted; PEPR: n¼30, 67(10) years, 52 (20)% predicted). The proportion of patients readmitted to hospital with an exacerbation was 33% in the UC group compared with 7% in those receiving PEPR (OR 0.15, 95% CI 0.03 to 0.72, p¼0.02). The proportion of patients that experienced an exacerbation resulting in an unplanned hospital attendance (either admission or review and discharge from the emergency department) was 57% in the UC group and 27% in those receiving PEPR (OR 0.28, 95% CI 0.10 to 0.82, p¼0.02). Conclusions Post-exacerbation rehabilitation in COPD can reduce re-exacerbation events that require admission or hospital attendance over a 3-month period. Clinical Trials Registration Number NCT00557115.

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People with advanced chronic obstructive pulmonary disease (COPD) have distressing physical and psychological symptoms, often have limited understanding of their disease, and infrequently discuss end-of-life issues in routine clinical care. These are strong indicators for expert multidisciplinary palliative care, which incorporates assessment and management of symptoms and concerns, patient and caregiver education, and sensitive communication to elicit preferences for care towards the end of life. The unpredictable course of COPD and the difficulty of predicting survival are barriers to timely referral and receipt of palliative care. Early integration of palliative care with respiratory, primary care, and rehabilitation services, with referral on the basis of the complexity of symptoms and concerns, rather than prognosis, can improve patient and caregiver outcomes. Models of integrated working in COPD could include: services triggered by troublesome symptoms such as refractory breathlessness; short-term palliative care; and, in settings with limited access to palliative care, consultation only in specific circumstances or for the most complex patients.

Background: Respiratory muscle weakness is an important clinical problem. Tests of varying complexity and invasiveness are available to assess respiratory muscle strength. The relative precision of different tests in the detection of weakness is less clear, as is the value of multiple tests. Methods: The respiratory muscle function tests of clinical referrals who had multiple tests assessed in our laboratories over a 6-year period were analysed. Thresholds for weakness for each test were determined from published and in-house laboratory data. The patients were divided into three groups: those who had all relevant measurements of global inspiratory muscle strength (group A, n = 182), those with full assessment of diaphragm strength (group B, n = 264) and those for whom expiratory muscle strength was fully evaluated (group C, n = 60). The diagnostic outcome of each inspiratory, diaphragm and expiratory muscle test, both singly and in combination, was studied and the impact of using more than one test to detect weakness was calculated. Results: The clinical referrals were primarily for the evaluation of neuromuscular diseases and dyspnoea of unknown cause. A low maximal inspiratory mouth pressure (PImax) was recorded in 40.1% of referrals in group A, while a low sniff nasal pressure (Sniff Pnasal) was recorded in 41.8% and a low sniff oesophageal pressure (Sniff Poes) in 37.9%. When assessing inspiratory strength with the combination of all three tests, 29.6% of patients had weakness. Using the two non-invasive tests (PImax and Sniff Pnasal) in combination, a similar result was obtained (low in 32.4%). Combining Sniff Pdi (low in 68.2%) and Twitch Pdi (low in 67.4%) reduced the diagnoses of patients with diaphragm weakness to 55.3% in group B. 38.3% of the patients in group C had expiratory muscle weakness as measured by maximum expiratory pressure (PEmax) compared with 36.7% when weakness was diagnosed by cough gastric pressure (Pgas), and 28.3% when assessed by Twitch T10. Combining all three expiratory muscle tests reduced the number of patients diagnosed as having expiratory muscle weakness to 16.7%. Conclusion: The use of single tests such as PImax, PEmax and other available individual tests of inspiratory, diaphragm and expiratory muscle strength tends to overdiagnose weakness. Combinations of tests increase diagnostic precision and, in the population studied, they reduced the diagnosis of inspiratory, specific diaphragm and expiratory muscle weakness by 19-56%. Measuring both PImax and Sniff Pnasal resulted in a relative reduction of 19.2% of patients falsely diagnosed with inspiratory muscle weakness. The addition of Twitch Pdi to Sniff Pdi increased diagnostic precision by a smaller amount (18.9%). Having multiple tests of respiratory muscle function available both increases diagnostic precision and makes assessment possible in a range of clinical circumstances.

The excellent compliance with wearing a physical activity monitor irrespective of study site and consistent associations with relevant disease characteristics support the use of activity monitoring as a valid outcome in multi-center studies.