Factors affecting survival of hospitalised patients with COPD

Hospitalization with acute exacerbation of chronic obstructive pulmonary disease and associated health resource utilization: a population-based Danish cohort study

OBJECTIVE

Health resource utilization (HRU) and outcomes associated with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) are not well described. Therefore, a population-based cohort study was conducted to characterize patients hospitalized with AECOPD with regard to HRU, mortality, recurrence, and predictors of readmission with AECOPD.

METHODS

Using Danish healthcare databases, this study identified COPD patients with at least one AECOPD hospitalization between 2005-2009 in Northern Denmark. Hospitalized AECOPD patients' HRU, in-hospital mortality, 30-day, 60-day, 90-day, and 180-day post-discharge mortality and recurrence risk, and predictors of readmission with AECOPD in the year following study inclusion were characterized.

RESULTS

This study observed 6612 AECOPD hospitalizations among 3176 prevalent COPD patients. Among all AECOPD hospitalizations, median length of stay was 6 days (interquartile range [IQR] 3-9 days); 5 days (IQR 3-9) among those without ICU stay and 11 days (IQR 7-20) among the 8.6% admitted to the ICU. Mechanical ventilation was provided to 193 (2.9%) and non-invasive ventilation to 479 (7.2%) admitted patients. In-hospital mortality was 5.6%. Post-discharge mortality was 4.2%, 7.8%, 10.5%, and 17.4% at 30, 60, 90, and 180 days, respectively. Mortality and readmission risk increased with each AECOPD hospitalization experienced in the first year of follow-up. Readmission at least twice in the first year of follow-up was observed among 286 (9.0%) COPD patients and was related to increasing age, male gender, obesity, asthma, osteoporosis, depression, myocardial infarction, diabetes I and II, any malignancy, and hospitalization with AECOPD or COPD in the prior year.

LIMITATIONS

The study included only hospitalized AECOPD patients among prevalent COPD patients. Furthermore, information was lacking on clinical variables.

CONCLUSION

These findings indicate that AECOPD hospitalizations are associated with substantial mortality and risk of recurrence.

K. Jindal for the COPD Guidelines Working Group. Guidelines for diagnosis and management of chronic obstructive pulmonary disease: Joint ICS/NCCP (I) recommendations

Chronic obstructive pulmonary disease (COPD) is a major public health problem in India. Although several International guidelines for diagnosis and management of COPD are available, yet there are lot of gaps in recognition and management of COPD in India due to vast differences in availability and affordability of healthcare facilities across the country. The Indian Chest Society (ICS) and the National College of Chest Physicians (NCCP) of India have joined hands to come out with these evidence-based guidelines to help the physicians at all levels of healthcare to diagnose and manage COPD in a scientific manner. Besides the International literature, the Indian studies were specifically analyzed to arrive at simple and practical recommendations. The evidence is presented under these five headings: (a) definitions, epidemiology, and disease burden; (b) disease assessment and diagnosis; (c) pharmacologic management of stable COPD; (d) management of acute exacerbations; and (e) nonpharmacologic and preventive measures. The modified grade system was used for classifying the quality of evidence as 1, 2, 3, or usual practice point (UPP). The strength of recommendation was graded as A or B depending upon the level of evidence.

Day-to-day measurement of patient-reported outcomes in exacerbations of chronic obstructive pulmonary disease

Background

Exacerbations of chronic obstructive pulmonary disease (COPD) are a major burden to patients and to society. Little is known about the possible role of day-to-day patient-reported outcomes during an exacerbation. This study aims to describe the day-to-day course of patient-reported health status during exacerbations of COPD and to assess its value in predicting clinical outcomes.

Methods

Data from two randomized controlled COPD exacerbation trials (n = 210 and n = 45 patients) were used to describe both the feasibility of daily collection of and the day-to-day course of patient-reported outcomes during outpatient treatment or admission to hospital. In addition to clinical parameters, the BORG dyspnea score, the Clinical COPD Questionnaire (CCQ), and the St George’s Respiratory Questionnaire were used in Cox regression models to predict treatment failure, time to next exacerbation, and mortality in the hospital study.

Results

All patient-reported outcomes showed a distinct pattern of improvement. In the multivariate models, absence of improvement in CCQ symptom score and impaired lung function were independent predictors of treatment failure. Health status and gender predicted time to next exacerbation. Five-year mortality was predicted by age, forced expiratory flow in one second % predicted, smoking status, and CCQ score. In outpatient management of exacerbations, health status was found to be less impaired than in hospitalized patients, while the rate and pattern of recovery was remarkably similar.

Conclusion

Daily health status measurements were found to predict treatment failure, which could help decision-making for patients hospitalized due to an exacerbation of COPD.

Chronic Obstructive Pulmonary Disease: Inpatient Management

This article outlines the management of patients with acute exacerbations of chronic obstructive pulmonary disease (COPD), which are common in the course of chronic COPD and are associated with substantial morbidity. There are numerous guidelines, but literature suggests that there is substantial variation in care in patients with acute exacerbations of COPD. Key components of acute therapy for most patients include oral steroids, antibiotics, nebulizers, oxygen, and early consideration of noninvasive ventilation. Adjuvant components of care include venous thromboembolism prophylaxis, appropriate immunizations, counseling for smoking cessation, and consideration of pulmonary rehabilitation.

Do we know the minimal clinically important difference (MCID) for COPD exacerbations?

Frequent exacerbations of COPD are associated with accelerated loss of lung function, declining health status, increased mortality, and increased health care costs. Thus, a key objective in the management of COPD is preventing exacerbations or at least reducing their number and severity. When new interventions are examined, their value is sometimes assessed in reference to the minimal clinically important difference (MCID), a theoretical construct that may be defined and estimated numerically in several different ways. There have been limited attempts to calculate the MCID for COPD exacerbations but a figure of 20% reduction in exacerbation frequency is occasionally cited as the "established" MCID from a single manuscript reviewing six clinical trials. Our review suggests that defining and calculating the MCID for COPD exacerbations is problematic, not only because the methodology around developing endpoints for MCIDs is inconsistent, but because the impact of exacerbation reduction is likely to be influenced dramatically by the definitions of exacerbation severity used and the population's baseline status. Reference to current literature shows that at least one other estimate for exacerbation MCID as low as 4%. MCID is sometimes estimated by expert consensus; a review of articles used to shape COPD guidelines shows frequent reference to articles in which interventions yielded exacerbation differences as low as 11%. We find no evidence of an established MCID but suggest that interventions reducing exacerbations by as little as 11% appear to be regarded widely as clinically important.

Nutritional status and disease severity in patients with chronic obstructive pulmonary disease (COPD)

The purpose of this study was to identify the relationship between nutritional status and the severity of the disease in patients with COPD in South Korea. This study used pretest data from a larger intervention study. Data were collected from March to October 2010, and 251 patients diagnosed with COPD from five hospitals in South Korea were included in the analysis. All participants were interviewed face-to-face. Actual dietary intake was measured by a 24-h dietary recall, and the body mass index (BMI), obstruction of the airway (FEV1% predicted), degree of dyspnea (modified Medical Research Council: MMRC), and exercise capacity (6min walking distance: 6MWD) (BODE) index was calculated to estimate the severity of the condition. Lower BODE index scores indicate lower risk of mortality. The data were analyzed by descriptive statistics, a χ(2) test, t-tests, analysis of variance (ANOVA), Pearson correlation, and hierarchical multiple regression using SPSS 18.0. The mean age of the participants was 66.83 years and 92.4% of the participants were men. The mean total energy intake was 1431.65kcal, and the mean BODE index score was 2.89. Total energy intake significantly explained additional variance in BODE, BMI, the severity of the perceived dyspnea, and the length of 6min walk after controlling for age, duration after diagnosed with COPD, and physical activities. The findings of this study emphasized the importance of calorie intake in the disease severity among COPD patients. Further research on the effects of nutritional intervention on the health outcomes of patients with COPD is warranted.

Chronic bronchial infection in COPD. Is there an infective phenotype?

Microorganisms, particularly bacteria, are frequently found in the lower airways of COPD patients, both in stable state and during exacerbations. The host–pathogen relationship in COPD is a complex, dynamic process characterised by frequent changes in pathogens, their strains and loads, and subsequent host immune responses.

Exacerbations are detrimental events in the course of COPD and evidence suggests that 70% may be caused by microorganisms. When considering bacterial exacerbations, recent findings based on molecular typing have demonstrated that the acquisition of new strains of bacteria or antigenic changes in pre-existing strains are the most important triggers for exacerbation onset.

Even in clinically stable COPD patients the presence of microorganisms in their lower airways may cause harmful effects and induce chronic low-grade airway inflammation leading to increased exacerbation frequency, an accelerated decline in lung function and impaired health-related quality of life. Besides intraluminal localisation in the distal airways, bacteria can be found in the bronchial walls and parenchymal lung tissue of COPD patients. Therefore, the isolation of pathogenic bacteria in stable COPD should be considered as a form of chronic infection rather than colonisation. This new approach may have important implications for the management of patients with COPD.

Predictors of 1-year mortality at hospital admission for acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Acute exacerbations of chronic obstructive pulmonary disease (AE-COPD) are related to high mortality, especially in hospitalized patients. Predictors for severe outcomes are still not sufficiently defined.

OBJECTIVES

To assess the mortality rate and identify potential determinants of mortality in a cohort of patients hospitalized for AE-COPD.

METHODS

A retrospective, observational cohort study including all consecutive patients admitted between January 1, 2009, and April 1, 2010, for AE-COPD. Potential predictors were assessed at initial presentation at the emergency room. The primary outcome was mortality during 1-year follow-up. Univariate and multivariate time-to-event analyses using Cox proportional hazard models were employed for statistical analysis.

RESULTS

A total of 260 patients were enrolled in this study. Mean age was 70.5 ± 10.8 years, 50.0% were male and 63.4% had severe COPD. The in-hospital mortality rate was 5.8% and the 1-year mortality rate was 27.7%. Independent risk factors for mortality were age [hazard ratio (HR) = 1.04; 95% confidence interval (CI) = 1.01-1.07], male sex (HR = 2.00; 95% CI = 1.15-3.48), prior hospitalization for AE-COPD in the last 2 years (HR = 2.56; 95% CI = 1.52-4.30), prior recorded congestive heart failure (HR = 1.75; 95% CI = 1.03-2.97), PaCO₂ ≥6.0 kPa (HR = 2.90; 95% CI = 1.65-5.09) and urea ≥8.0 mmol/l (HR = 2.38; 95% CI = 1.42-3.99) at admission.

CONCLUSIONS

Age, male sex, prior hospitalization for AE-COPD in the last 2 years, prior recorded congestive heart failure, hypercapnia and elevated levels of urea at hospital admission are independent predictors of mortality within the first year after admission.

Long-term survival in patients hospitalized for chronic obstructive pulmonary disease: a prospective observational study in the Nordic countries

Background and aim

Mortality rate is high in patients with chronic obstructive pulmonary disease (COPD). Our aim was to investigate long-term mortality and associated risk factors in COPD patients previously hospitalized for a COPD exacerbation.

Methods

A total of 256 patients from the Nordic countries were followed for 8.7 ± 0.4 years after the index hospitalization in 2000–2001. Prior to discharge, the St George’s Respiratory Questionnaire was administered and data on therapy and comorbidities were obtained. Information on long-term mortality was obtained from national registries in each of the Nordic countries.

Results

In total, 202 patients (79%) died during the follow up period, whereas 54 (21%) were still alive. Primary cause of death was respiratory (n = 116), cardiovascular (n = 43), malignancy (n = 28), other (n = 10), or unknown (n = 5). Mortality was related to older age, with a hazard risk ratio (HRR) of 1.75 per 10 years, lower forced expiratory volume in 1 second (FEV₁) (HRR 0.80), body mass index (BMI) <20 kg/m² (HRR 3.21), and diabetes (HRR 3.02). Older age, lower BMI, and diabetes were related to both respiratory and cardiovascular mortality. An association was also found between lower FEV₁ and respiratory mortality, whereas mortality was not significantly associated with therapy, anxiety, or depression.

Conclusion

Almost four out of five patients died within 9 years following an admission for COPD exacerbation. Increased mortality was associated with older age, lower lung function, low BMI, and diabetes, and these factors should be taken into account when making clinical decisions about patients who have been admitted to hospital for a COPD exacerbation.

Body mass index and mortality in chronic obstructive pulmonary disease: a meta-analysis

Background

The association between body mass index (BMI) and mortality in patients suffering from chronic obstructive pulmonary disease (COPD) has been a subject of interest for decades. However, the evidence is inadequate to draw robust conclusions because some studies were generally small or with a short follow-up.

Methods

We carried out a search in MEDLINE, Cochrane Central Register of Controlled Trials, and EMBASE database for relevant studies. Relative risks (RRs) with 95% confidence interval (CI) were calculated to assess the association between BMI and mortality in patients with COPD. In addition, a baseline risk-adjusted analysis was performed to investigate the strength of this association.

Results

22 studies comprising 21,150 participants were included in this analysis. Compared with patients having a normal BMI, underweight individuals were associated with higher mortality (RR  = 1.34, 95% CI  = 1.01–1.78), whereas overweight (RR  = 0.47, 95% CI  = 0.33–0.68) and obese (RR  = 0.59, 95% CI  = 0.38–0.91) patients were associated with lower mortality. We further performed a baseline risk-adjusted analysis and obtained statistically similar results.

Conclusion

Our study showed that for patients with COPD being overweight or obese had a protective effect against mortality. However, the relationship between BMI and mortality in different classes of obesity needed further clarification in well-designed clinical studies.

Acetazolamide: a second wind for a respiratory stimulant in the intensive care unit?

Patients with chronic obstructive pulmonary disease (COPD) are affected by episodes of respiratory exacerbations, some of which can be severe and may necessitate respiratory support. Prolonged invasive mechanical ventilation is associated with increased mortality rates. Persistent failure to discontinue invasive mechanical ventilation is a major issue in patients with COPD. Pure or mixed metabolic alkalosis is a common finding in the intensive care unit (ICU) and is associated with a worse outcome. In patients with COPD, the condition is called post-hypercapnic alkalosis and is a complication of mechanical ventilation. Reversal of metabolic alkalosis may facilitate weaning from mechanical ventilation of patients with COPD. Acetazolamide, a non-specific carbonic anhydrase inhibitor, is one of the drugs employed in the ICU to reverse metabolic alkalosis. The drug is relatively safe, undesirable effects being rare. The compartmentalization of the different isoforms of the carbonic anhydrase enzyme may, in part, explain the lack of evidence of the efficacy of acetazolamide as a respiratory stimulant. Recent findings suggest that the usually employed doses of acetazolamide in the ICU may be insufficient to significantly improve respiratory parameters in mechanically ventilated patients with COPD. Randomized controlled trials using adequate doses of acetazolamide are required to address this issue.

Invasive Mechanical Ventilation in Acute Exacerbation of COPD: Prognostic Indicators to Support Clinical Decision Making

Although non-invasive ventilation is the mainstay of management for patients with hypercapnic acute exacerbation of COPD, invasive mechanical ventilation (IMV) still has an important role to play. IMV can be used successfully to reduce mortality and still maintain quality of life in a subset of patients. Despite this, the evidence to support which patients will benefit from IMV is limited. This article reviews the literature available to guide clinician decision-making. Age is not a reliable independent predictor of survival for COPD patients receiving IMV, nor are levels of PaO2, PCO2, or use of long-term oxygen therapy. Body composition and nutritional status are independent predictors of survival and the presence of co-morbidities, such as cor pulmonale, cardiovascular disease and diabetes mellitus are negative prognostic indicators. Length of time in hospital prior to ICU admission also is an adverse prognostic factor. Although scoring systems exist, their ability to predict outcome for individual patients has limitations. Work needs to be done to improve end-of-life planning in COPD with the encouragement of discussion about advance directives when patients are reaching advanced stage of the disease.

Impact of clinical pathway on clinical outcomes in the management of COPD exacerbation

Background

Exacerbations, a leading cause of hospitalization in patients with chronic obstructive pulmonary disease (COPD), affect the quality of life and prognosis. Treatment recommendations as provided in the evidence-based guidelines are not consistently followed, partly due to absence of simplified task-oriented approach to care. In this study, we describe the development and implementation of a clinical pathway (CP) and evaluate its effectiveness in the management of COPD exacerbation.

Methods

We developed a CP and evaluated its effectiveness in a non-randomized prospective study with historical controls on patients admitted for exacerbation of COPD to Universiti Kebangsaan Malaysia Medical Centre (UKMMC). Consecutive patients who were admitted between June 2009 and December 2010 were prospectively recruited into the CP group. Non-CP historical controls were obtained from case records of patients admitted between January 2008 and January 2009. Clinical outcomes were evaluated by comparing the length of stay (LOS), complication rates, readmissions, and mortality rates.

Results

Ninety-five patients were recruited in the CP group and 98 patients were included in the non-CP historical group. Both groups were comparable with no significant differences in age, sex and severity of COPD (p = 0.641). For clinical outcome measures, patients in the CP group had shorter length of stay than the non-CP group (median (IQR): 5 (4–7) days versus 7 (7–9) days, p < 0.001) and 24.1% less complications (14.7% versus 38.8%, p < 0.001). We did not find any significant differences in readmission and mortality rates.

Conclusion

The implementation of CP –reduced the length of stay and complication rates of patients hospitalized for acute exacerbation of COPD.

Systematic review of noncancer presentations with a median survival of 6 months or less

PURPOSE

We report on clinical indicators of 6-month mortality in advanced noncancer illnesses and the effect of treatment on survival.

METHODS

The MEDLINE database was searched comprehensively to find studies evaluating survival for common advanced noncancer illnesses. We retrieved and evaluated studies that reported a median survival of ≤1 year and evaluated prognostic factors or effect of treatment on survival. We extracted data on presentations with median survivals of ≤6 months for heart failure, chronic obstructive pulmonary disease, dementia, geriatric failure to thrive, cirrhosis, and end-stage renal failure. Independent risk factors for survival were combined and included if their combination was associated with a 6-month mortality of ≥50%.

RESULTS

The search identified 1000 potentially relevant studies, of which 475 were retrieved and evaluated, and 74 were included. We report the common clinical presentations that are consistently associated with a 6-month median survival. Even though advanced noncancer syndromes differ clinically, a universal set of prognostic factors signals progression to terminal disease, including poor performance status, advanced age, malnutrition, comorbid illness, organ dysfunction, and hospitalization for acute decompensation. Generally, a 6-month median survival is associated with the presence of 2-4 of these factors. With few exceptions, these terminal presentations are quite refractory to treatment.

CONCLUSION

This systematic review summarizes prognostic factors common to advanced noncancer illness. There is little evidence at present that treatment prolongs survival at these terminal stages.

Anemia is a mortality predictor in hospitalized patients for COPD exacerbation

BACKGROUND

Anemia is a recognized prognostic factor in many chronic illnesses, but there is limited information about its impact on outcomes in patients hospitalized for acute COPD exacerbation (AECOPD).

AIM

To investigate whether anemia exerts an effect on mortality in patients admitted for AECOPD after one year of follow-up. Methods. From November 2007 to November 2009 we recruited 117 patients who required hospitalization due to an AECOPD. Clinical, functional and laboratory parameters on admission were prospectively assessed. Patients were followed up during one year. Mortality and days-to-death were collected.

RESULTS

Mean age 72 (SD ± 9); FEV₁ 37.4 (SD ± 12); mortality after 1 year was 22.2%. Mean survival: 339 days. Comparing patients who died to those who survived we found significant differences (p < 0,000) in hemoglobin (Hb) (12.4 vs 13.8 mg/dl) and hematocrit (Ht) (38 vs 41%). Anemia (Hb < 13 g.dl⁻¹) prevalence was 33%. Those who died had experienced 3.5 exacerbations in previous year vs 1.5 exacerbations in the case of the survivors (p = 0.000). Lung function and nutritional status were similar, except for percentage of muscle mass (%) (35 vs 39%; p = 0.015) and albumin (33 vs 37 mg/dl; p = 0.039). These variables were included in a Multivariate Cox Proportional Hazards Model; anemia and previous exacerbations resulted as independent factors for mortality. Mortality risk for patients with anemia was 5.9(CI: 1.9-19); for patients with > 1 exacerbation in the previous year was 5.9(CI: 1.3-26.5).

CONCLUSION

Anemia and previous exacerbations were independent predictors of mortality after one year in patients hospitalized for AECOPD.

Impact of COPD exacerbations on osteoporosis assessed by chest CT scan

Background: COPD pathology involves not only the lungs but also extrapulmonary abnormalities. Osteoporosis is one of the most important abnormalities because it may cause vertebral compression fractures and deteriorate pulmonary function. COPD patients have many risk factors for osteoporosis, such as low BMI, decreased activity, systemic inflammation, and use of corticosteroids. Some of these factors have been shown to deteriorate with COPD exacerbations. We previously demonstrated the correlation between emphysema and osteoporosis and between emphysema progression and COPD exacerbations. Thus, the hypothesis that exacerbation causes osteoporosis progression in COPD patients was investigated. Methods: Forty-two COPD patients not on osteoporosis treatment for over 2 years were recruited. During follow-up, exacerbations had been prospectively recorded. Thoracic vertebral bone mineral density (BMD) was measured using chest CT, and the annual change in BMD was calculated. The change was compared between patients with and without a history of exacerbations. Results: The decrease in thoracic vertebral BMD was greater in patients with than in those without a history of exacerbations (median ABMD mg/ml year: −3.78 versus −0.30, p = 0.02). Moreover, multivariate regression analysis showed that exacerbations and baseline Pa0₂ were independent predictors of the BMD decrease (R² = 0.20, p = 0.007, and R² = 0.09, p = 0.03, respectively) after adjustment for baseline age, smoking status, and airflow limitation. Conclusions: This is the first longitudinal study to demonstrate that COPD exacerbations are independently associated with osteoporosis progression. Osteoporosis progression should be evaluated in COPD patients, especially in those with a history of frequent exacerbations.

Long-term follow-up of chronic obstructive pulmonary disease patients on long-term oxygen treatment

AIMS

Few studies exist on influence of long-term oxygen treatment (LTOT) on survival of chronic obstructive pulmonary disease (COPD) patients. This study was designed to determine whether LTOT improves survival or not in severely hypoxaemic COPD patients.

MATERIALS

COPD patients prescribed oxygen concentrator were consecutively included. Patients' baseline characteristics were noted. During follow-up, patients were divided into three groups according to LTOT utilisation: (i) non-utilisers, (ii) intermittent utilisers (< 15 h/day) and (iii) true utilisers (≥ 15 h/day). Patients' status (live or death) and, if died, the date of death were checked throughout the study. The factors which might influence mortality during 5-year period were analysed.

RESULTS

Two-hundred and twenty-eight patients completed the study. Of these patients, 55 were in Group 1, 112 were in Group 2 and 61 were in Group 3. Regarding the initial characteristics, there was not any significant difference between groups. Mean follow-up for whole group was 27.8 ± 18.5 months. Median survivals were similar between groups (19.5 ± 5.6, 32.5 ± 4.1 and 30.0 ± 5.7 months respectively) (p > 0.05). Compared with Group 1, survival was improved in Group 2 (p < 0.05) and there was a positive trend for Group 3 during first 2-year period. However, this improvement disappeared during further follow-up. Analysis of multiple factors which might influence mortality during 5-year period did not yield statistically significant parameter.

DISCUSSION AND CONCLUSION

We found that, regarding survival, any kind of LTOT proved to be beneficial over no LTOT only in the first 2 years of follow-up, and that there was not any difference between intermittent and true LTOT utilisation.

Serum albumin and survival in glioblastoma multiforme

Serum albumin is an established predictor of survival in numerous cancers but its prognostic value in central nervous system tumours has not been established. Here we have examined prognostic factors in 685 patients with histologically proven glioblastoma multiforme (GBM), the majority of which (n = 549) had pre-operative serum albumin assayed. Mean serum albumin was 34.7 g/l (SD 5.2). Post-operative survival was significantly less for patients with hypoalbuminaemia (<30 g/l, n = 82) than for patients with normal albumin level (median 2.3 vs. 5.6 months, P < 0.001 Log-rank test). Furthermore, patients with lower normal albumin (30-40 g/l, n = 371) had significantly shorter survival compared against patients with albumin in the upper normal range (40-50 g/l, n = 96; median 5.1 vs. 8.8 months, P < 0.001). Multivariate Cox regression showed the independent predictors of survival were age, debulking surgery, chemoradiotherapy, and serum albumin (Hazard Ratio 0.97 per g/l, P < 0.005). This study suggests pre-operative serum albumin level is a significant predictor of survival in patients with GBM. Further studies are needed to examine the relationship between albumin and other known prognostic factors, and to determine if pre-operative serum albumin is a clinically useful predictor of survival.

Population pharmacodynamic model of bicarbonate response to acetazolamide in mechanically ventilated chronic obstructive pulmonary disease patients

INTRODUCTION

Acetazolamide is commonly given to chronic obstructive pulmonary disease (COPD) patients with metabolic alkalosis. Little is known of the pharmacodynamics of acetazolamide in the critically ill. We undertook the pharmacodynamic modeling of bicarbonate response to acetazolamide in COPD patients under mechanical ventilation.

METHODS

This observational, retrospective study included 68 invasively ventilated COPD patients who received one or multiple doses of 250 or 500 mg of acetazolamide during the weaning period. Among the 68 investigated patients, 207 time-serum bicarbonate observations were available for analysis. Population pharmacodynamics was modeled using a nonlinear mixedeffect model. The main covariates of interest were baseline demographic data, Simplified Acute Physiology Score II (SAPS II) at ICU admission, cause of respiratory failure, co-prescription of drugs interfering with the acid-base equilibrium, and serum concentrations of protein, creatinin, potassium and chloride. The effect of acetazolamide on serum bicarbonate levels at different doses and in different clinical conditions was subsequently simulated in silico.

RESULTS

The main covariates interacting with acetazolamide pharmacodynamics were SAPS II at ICU admission (P = 0.01), serum chloride (P < 0.001) and concomitant administration of corticosteroids (P = 0.02). Co-administration of furosemide significantly decreased bicarbonate elimination. Acetazolamide induced a decrease in serum bicarbonate with a dose-response relationship. The amount of acetazolamide inducing 50% of the putative maximum effect was 117 ± 21 mg. According to our model, an acetazolamide dosage > 500 mg twice daily is required to reduce serum bicarbonate concentrations > 5 mmol/L in the presence of high serum chloride levels or coadministration of systemic corticosteroids or furosemide.

CONCLUSIONS

This study identified several covariates that influenced acetazolamide pharmacodynamics and could allow a better individualization of acetazolamide dosing when treating COPD patients with metabolic alkalosis.

Body mass index and prognosis in patients hospitalized with acute exacerbation of chronic obstructive pulmonary disease

BACKGROUND: Nutritional status, weight loss and cachexia have important prognostic implications in patients with chronic obstructive pulmonary disease (COPD). Body mass index (BMI) has been implicated in COPD risk assessment, but information is mostly limited to composite scores or to patients with stable disease. We aimed to analyse the association between BMI and mortality in acute exacerbation of COPD. METHODS: This retrospective survey included 968 patients hospitalized due to acute exacerbation of COPD at the University Clinic Golnik from February 2002 to June 2007. Vital status was ascertained with Central Population Registry, and database was censored on November 1, 2008. RESULTS: Median BMI was 25.08 kg/m(2) (interquartile range, 21.55-29.05 kg/m(2)) and 210 patients (22%) had BMI < 21 kg/m(2). During median follow-up of 3.26 years (1.79-4.76 years), 430 patients (44%) died. Lowest mortality was found for BMI 25.09-29.05 kg/m(2). When divided per BMI decile, mortality was lowest for BMI 25.09-26.56 kg/m(2) (33%). In univariate analysis, BMI per quartile and BMI per unit increase were predictive for all-cause mortality. In an adjusted model, BMI per 1 kg/m(2) unit increase was associated with 5% less chance of death (hazard ratio 0.95, 95% confidence interval 0.93-0.97). CONCLUSIONS: Low BMI < 21 kg/m(2) is frequent in patients hospitalized due to acute exacerbation of COPD. Higher BMI was independently predictive of better long-term survival. A better outcome in obese patients compared to normal weight is in contrast to primary prevention data but concurs with observations of an obesity paradox in other cardiovascular diseases.

Routine laboratory tests can predict in-hospital mortality in acute exacerbations of COPD

Chronic obstructive pulmonary disease (COPD) has a rising global incidence and acute exacerbation of COPD (AECOPD) carries a high health-care economic burden. Classification and regression tree (CART) analysis is able to create decision trees to classify risk groups. We analysed routinely collected laboratory data to identify prognostic factors for inpatient mortality with AECOPD from our large district hospital. Data from 5,985 patients with 9,915 admissions for AECOPD over a 7-year period were examined. Randomly allocated training (n = 4,986) or validation (n = 4,929) data sets were developed and CART analysis was used to model the risk of all-cause death during admission. Inpatient mortality was 15.5%, mean age was 71.5 (±11.5) years, 56.2% were male, and mean length of stay was 9.2 (±12.2) days. Of 29 variables used, CART analysis identified three (serum albumin, urea, and arterial pCO(2)) to predict in-hospital mortality in five risk groups, with mortality ranging from 3.0 to 23.4%. C statistic indices were 0.734 and 0.701 on the training and validation sets, respectively, indicating good model performance. The highest-risk group (23.4% mortality) had serum urea >7.35 mmol/l, arterial pCO(2) >6.45 kPa, and normal serum albumin (>36.5 g/l). It is possible to develop clinically useful risk prediction models for mortality using laboratory data from the first 24 h of admission in AECOPD.

[Cardiovascular comorbidity in COPD]

The presence of cardiovascular alterations in patients with chronic obstructive pulmonary disease (COPD) is no coincidence. Smoking, a risk factor for both entities, could partly explain the strength of the association; however, there are data that suggest that other determining factors such as systemic inflammation, oxidative stress, hypoxemia, endothelial dysfunction and even aging could also be involved. Prognosis is worse in patients with both entities. Cardiovascular disease (CVD) contributes to hospitalization in patients with COPD and to mortality. Approximately one out of every four patients with COPD dies from cardiovascular causes. Equally, COPD exacerbation also leads to a greater number of cardiovascular events and an increase in mortality has even been found among patients with CVD and COPD compared with controls without COPD. These determining factors underline the need to develop a comprehensive view for the early detection of at-risk individuals and use of appropriate therapeutic measures. Vasodilators, statins and beta-blockers may improve morbidity and mortality in patients with COPD, possibly because these drugs maximize control of the underlying CVD. Nevertheless, the antiinflammatory potential of statins could be of interest. Inhaled corticosteroids and even some bronchodilators could also decrease cardiovascular morbidity. These data are from observational studies and should be interpreted with caution but are nevertheless sufficiently interesting to warrant the enormous interest aroused by the interaction between the two most prevalent chronic diseases in the western world, COPD and CVD.

Antibiotic therapy for exacerbations of chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD) is already the world's fourth most common cause of mortality and likely to become the third in a few year's time. Because it is an inflammatory airway disease with altered host immune response, infectious complications are frequent. Acute exacerbations of COPD (AECOPD) significantly worsen the patient's general health, accelerating disability. Each exacerbation leads progressively to further deterioration of lung function. Among the various causes of AECOPD, including viruses, bacteria and air pollution, a bacterial etiology is most common (50-69%). The management of AECOPD remains extremely challenging and places a heavy economic burden on health care institutions. The decision to administer antibiotics in AECOPD is multifactorial, the most important considerations being severity of the COPD stage and patient performance status, clinical symptoms (increased dyspnea, sputum volume and sputum purulence), severity of current and previous exacerbations, comorbidity and current smoking. Exacerbations which require hospital admission are associated with significant in-patient mortality. AECOPD patients presenting with worsening dyspnea, increased sputum volume and purulence should be offered antimicrobial therapy. If treating with antibiotics, treatment must include coverage for Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis in all cases, but other bacteria (such as Gram-negatives) may need to be covered depending on the condition of the patient. Antibiotics, particularly macrolides and fluoroquinolones, when administered under suitable conditions, shorten the clinical course and prevent severe deterioration. possible complications resulting from untreated severe AECOPD surpass the potential risks from the use of antibiotic therapy. Additional anti-inflammatory and immunomodulatory actions of some antibiotics may contribute to their efficacy in AECOPD.

COPD exacerbation: mortality prognosis factors in a respiratory care unit

OBJECTIVE

The aim of our study was to investigate the mortality predictive factors after a severe exacerbations of COPD admitted to a Spanish respiratory intermediate care unit (IRCU).

PATIENTS AND METHODS

Prospective observational 2 years study, where we included all episodes of acute exacerbations of COPD with hypercapnic respiratory failure admitted in an IRCU. We analyzed different sociodemographic, functional and clinical variables including physical activity.

RESULTS

We collected data from 102 consecutive episodes admitted to IRCU (90.1% men). Mean age was 69.4±10.6. The mean APACHE II was 19.6±5.0 and 9.5% presented a failure of other non respiratory organ. Non invasive ventilation was applied in 75.3% of the episodes and this treatment failed in 11.6% of them. The duration of stay in the IRCU was 3.5±2.1 days and 8.0±5.3 days in the hospital. The hospital mortality rate was 6.9%, and another 12.7% after 90 days of discharged. In order to predict hospital mortality, multivariant statistics identified a model with AUC of 0.867, based in 3 variables: the number of previous year admission for COPD exacerbation (p=0,048), the respiratory rate after 2 hours of treatment in the IRCU (p=0.0484) and the severity of the disease established with ADO score (p=0.0241).

CONCLUSIONS

The number of previous year admission for COPD exacerbation, the severity of the disease established with ADO score, the respiratory rate after 2 hours of treatment, allow us to identify what patients with a COPD exacerbation admitted in a IRCU can die during this episode.

WITHDRAWN: Antibiotics for exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Most patients with an exacerbation of chronic obstructive pulmonary disease (COPD) are treated with antibiotics. However the value of their use remains uncertain. Some controlled trials of antibiotics have shown benefit (Berry 1960; Pines 1972) while others have not (Elmes 1965b; Nicotra 1982).

OBJECTIVES

To conduct a systematic review of the literature estimating the value of antibiotics in the management of acute COPD exacerbations.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2005, issue 4) which contains the Acute Respiratory Infections Group's Specialized Register; MEDLINE (1966 to December 2005); EMBASE (1974 to December 2005); Web of Science (December 2005), and other electronically available databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in patients with acute COPD exacerbations comparing antibiotic (for a minimum of five days) and placebo.

DATA COLLECTION AND ANALYSIS

Data were analysed using Review Manager software. Continuous data were analysed using weighted mean differences (WMD) and 95% confidence intervals (CI). Relative risks (RR) (and 95% CI) were calculated for all dichotomous data. Where appropriate, number needed to treat to benefit (NNT) and 95% CI were calculated.

MAIN RESULTS

Eleven trials with 917 patients were included. Ten trials used increased cough, sputum volume and purulence diagnostic criteria for COPD exacerbation. Eight-hundred and fifty-seven patients provided data for outcomes including mortality, treatment failure, increased sputum volume, sputum purulence, PaCO(2), PaO(2), peak flow and adverse events. Antibiotic therapy regardless of antibiotic choice significantly reduced mortality (RR 0.23; 95% CI 0.10 to 0.52 with NNT of 8; 95% CI 6 to 17), treatment failure (RR 0.47; 95% CI 0.36 to 0.62 with NNT of 3; 95% CI 3 to 5) and sputum purulence (RR 0.56; 95% CI 0.41 to 0.77 with NNT of 8; 95% CI 6 to 17). There was a small increase in risk of diarrhoea with antibiotics (RR 2.86; 95% CI 1.06 to 7.76). Antibiotics did not improve arterial blood gases and peak flow.

AUTHORS' CONCLUSIONS

This review shows that in COPD exacerbations with increased cough and sputum purulence antibiotics, regardless of choice, reduce the risk of short-term mortality by 77%, decrease the risk of treatment failure by 53% and the risk of sputum purulence by 44%; with a small increase in the risk of diarrhoea. These results should be interpreted with caution due to the differences in patient selection, antibiotic choice, small number of included trials and lack of control for interventions that influence outcome, such as use of systemic corticosteroids and ventilatory support. Nevertheless, this review supports antibiotics for patients with COPD exacerbations with increased cough and sputum purulence who are moderately or severely ill.

The impact of care pathways for exacerbation of Chronic Obstructive Pulmonary Disease: rationale and design of a cluster randomized controlled trial

BACKGROUND

Hospital treatment of chronic obstructive pulmonary disease (COPD) frequently does not follow published evidences. This lack of adherence can contribute to the high morbidity, mortality and readmissions rates. The European Quality of Care Pathway (EQCP) study on acute exacerbations of COPD (NTC00962468) is undertaken to determine how care pathways (CP) as complex intervention for hospital treatment of COPD affects care variability, adherence to evidence based key interventions and clinical outcomes.

METHODS

An international cluster Randomized Controlled Trial (cRCT) will be performed in Belgium, Italy, Ireland and Portugal. Based on the power analysis, a sample of 40 hospital teams and 398 patients will be included in the study. In the control arm of the study, usual care will be provided. The experimental teams will implement a CP as complex intervention which will include three active components: a formative evaluation of the quality and organization of care, a set of evidence based key interventions, and support on the development and implementation of the CP. The main outcome will be six-month readmission rate. As a secondary endpoint a set of clinical outcome and performance indicators (including care process evaluation and team functioning indicators) will be measured in both groups.

DISCUSSION

The EQCP study is the first international cRCT on care pathways. The design of the EQCP project is both a research study and a quality improvement project and will include a realistic evaluation framework including process analysis to further understand why and when CP can really work.

TRIAL REGISTRATION NUMBER

NCT00962468.

Predicting outcomes following hospitalization for acute exacerbations of COPD

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are a frequent cause of hospital admission and are associated with significant morbidity, mortality, high readmission rates and high resource utilization. More accurate prediction of survival and readmission in patients hospitalized with AECOPD should help to optimize clinical management and allocation of resources, including targeting of palliative care and strategies to reduce readmissions. We have reviewed the published retrospective and prospective studies in this field to identify the factors most likely to be of value in predicting in-hospital and post-discharge mortality, and readmission of patients hospitalized for AECOPD. The prognostic factors which appear most important vary with the particular outcome under consideration. In-hospital mortality is related most clearly to the patient's acute physiological state and to the development of acute comorbidity, while post-discharge mortality particularly reflects the severity of the underlying COPD, as well as specific comorbidities, especially cardiac disease. Important factors influencing the frequency of readmission include functional limitation and poor health-related quality of life. Large prospective studies which incorporate all the potentially relevant variables are required to refine prediction of the important outcomes of AECOPD and thus to inform clinical decision making, for example on escalation of care, facilitated discharge and provision of palliative care.

Effect of high flow oxygen on mortality in chronic obstructive pulmonary disease patients in prehospital setting: randomised controlled trial

OBJECTIVES

To compare standard high flow oxygen treatment with titrated oxygen treatment for patients with an acute exacerbation of chronic obstructive pulmonary disease in the prehospital setting.

DESIGN

Cluster randomised controlled parallel group trial.

SETTING

Ambulance service in Hobart, Tasmania, Australia.

PARTICIPANTS

405 patients with a presumed acute exacerbation of chronic obstructive pulmonary disease who were treated by paramedics, transported, and admitted to the Royal Hobart Hospital during the trial period; 214 had a diagnosis of chronic obstructive pulmonary disease confirmed by lung function tests in the previous five years.

INTERVENTIONS

High flow oxygen treatment compared with titrated oxygen treatment in the prehospital (ambulance/paramedic) setting.

MAIN OUTCOME MEASURE

Prehospital or in-hospital mortality.

RESULTS

In an intention to treat analysis, the risk of death was significantly lower in the titrated oxygen arm compared with the high flow oxygen arm for all patients (high flow oxygen n=226; titrated oxygen n=179) and for the subgroup of patients with confirmed chronic obstructive pulmonary disease (high flow n=117; titrated n=97). Overall mortality was 9% (21 deaths) in the high flow oxygen arm compared with 4% (7 deaths) in the titrated oxygen arm; mortality in the subgroup with confirmed chronic obstructive pulmonary disease was 9% (11 deaths) in the high flow arm compared with 2% (2 deaths) in the titrated oxygen arm. Titrated oxygen treatment reduced mortality compared with high flow oxygen by 58% for all patients (relative risk 0.42, 95% confidence interval 0.20 to 0.89; P=0.02) and by 78% for the patients with confirmed chronic obstructive pulmonary disease (0.22, 0.05 to 0.91; P=0.04). Patients with chronic obstructive pulmonary disease who received titrated oxygen according to the protocol were significantly less likely to have respiratory acidosis (mean difference in pH 0.12 (SE 0.05); P=0.01; n=28) or hypercapnia (mean difference in arterial carbon dioxide pressure -33.6 (16.3) mm Hg; P=0.02; n=29) than were patients who received high flow oxygen.

CONCLUSIONS

Titrated oxygen treatment significantly reduced mortality, hypercapnia, and respiratory acidosis compared with high flow oxygen in acute exacerbations of chronic obstructive pulmonary disease. These results provide strong evidence to recommend the routine use of titrated oxygen treatment in patients with breathlessness and a history or clinical likelihood of chronic obstructive pulmonary disease in the prehospital setting.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Register ACTRN12609000236291.

Impact of tiotropium on the course of moderate-to-very severe chronic obstructive pulmonary disease: the UPLIFT trial

The Understanding Potential Long-term Improvements in Function with Tiotropium (UPLIFT) trial was a global 4-year randomized placebo-controlled clinical trial that evaluated the long-term impact of tiotropium bromide 18 microg once daily on the accelerated age-related decline in pre- and post-bronchodilator forced expiratory volume in 1 s (FEV(1); co-primary end points). Secondary end points included lung function at serial clinic visits, health-related quality of life, exacerbations, exacerbation-related hospitalizations, mortality, safety and tolerability. The study was carried out in 5992 patients (75% male, mean age 65 years, 30% current smokers) with moderate-to-very severe chronic obstructive pulmonary disease who were permitted to receive prescribed treatment with long-acting beta(2)-agonists and/or inhaled corticosteroids in addition to the study drug. While the results failed to show an effect of tiotropium on the primary end points (rate of decline in pre- and post-bronchodilator FEV(1)), they did show improvements in lung function and health-related quality of life that were maintained throughout the study and a reduction in the risk of exacerbations and related hospitalizations. Tiotropium also reduced all-cause mortality in patients on treatment over the 4-year trial period and reduced lower respiratory and cardiovascular morbidity, including respiratory failure and myocardial infarction. Adverse events were consistent with the drug's known anticholinergic pharmacology.

Low inspiratory capacity to total lung capacity ratio is a risk factor for chronic obstructive pulmonary disease exacerbation

INTRODUCTION

Air trapping because of chronic obstructive pulmonary disease (COPD) leads to a reduction in inspiratory capacity/total lung capacity (IC/TLC) ratio. We hypothesize that COPD patients with a low IC/TLC ratio suffer more frequent COPD exacerbations.

METHODS

Retrospective cohort study of patients with COPD, aged 30 years or older with forced expiratory volume in 1 second <70% predicted and forced expiratory volume in 1 second/forced expiratory volume (FEV1/FVC) ratio <70% treated in our ambulatory care clinic for 3 years (2003-2006). Patients were divided in 2 groups, either IC/TLC ratio less than or greater than 25%.

RESULTS

Charts of 350 patients with COPD were reviewed. Of the 77 patients who met inclusion criteria, 28 patients (20 women and 8 men) had IC/TLC ratio <25% (low group) and 49 patients (25 women and 24 men) had IC/TLC ratio >25% (high group). Average number of exacerbations per person in the low group was 3.5 (0-10), significantly higher than in the high group, which was 2.2 (0-10; P = 0.01). Visits for COPD exacerbations were analyzed based on treatment site namely, office, emergency room (ER), and hospital. The per person office visits were 1.96 (0-10) in the low group and 0.80 (0-3) in the high group (P = 0.002). ER visits were similar, 0.57 (0-3) in the low group and 0.38 (0-3) in the high group (P = 0.15), as were hospital visits, 0.96 (0-8) in the low group and 1.06 (0-5) in the high group (P = 0.81).

CONCLUSION

COPD patients in the low group experienced significantly more unscheduled office visits because of exacerbations, suggesting they need early identification and closely monitored therapy.

Preventing and managing exacerbations in COPD--critical appraisal of the role of tiotropium

The course of COPD is punctuated by acute exacerbations that are associated with an increase in the morbidity and mortality related to this chronic disease and may contribute to its rate of progression. Therefore, preventing and treating exacerbations are major goals of COPD management. The role of tiotropium in the prevention of exacerbations has been investigated in several placebo-controlled randomized clinical trials varying in duration from 3 months to 4 years in patients with moderate to very severe COPD. In all of these trials, tiotropium has uniformly reduced the proportion of patients experiencing at least one exacerbation and delayed the time to the first exacerbation compared with placebo. In the longer trials (> or =6 months' duration) tiotropium has also reduced the exposure-adjusted incidence rate of exacerbations. In trials of at least 1 year in duration, tiotropium either significantly reduced the risk of hospitalization for an exacerbation and/or the proportion of patients with an exacerbation-related hospitalization. In a meta-analysis that included 15 trials of tiotropium vs either placebo (n = 13) and/or a long-acting beta-agonist (LABA; n = 4), tiotropium significantly reduced the odds of experiencing an exacerbation compared to placebo as well as a LABA. The potential additive benefits of tiotropium to those of a LABA and/or inhaled corticosteroid in reducing exacerbations require further investigation. The mechanism whereby tiotropium reduces exacerbations is not due to an anti-inflammatory effect but more likely relates to its property of causing a sustained increase in airway patency and reduction in hyperinflation, thereby counteracting the tendency for respiratory insults to worsen airflow obstruction and hyperinflation. For the management of acute exacerbations, an increase in short-acting inhaled bronchodilators is recommended as needed, while the potential role of long-acting bronchodilators, such as tiotropium, in conjunction with short-acting agents, is unclear and warrants further study.

Inhospital management of COPD exacerbations: a systematic review of the literature with regard to adherence to international guidelines

Rationale Chronic obstructive pulmonary disease (COPD) exacerbations are a leading cause of hospitalization. Suboptimal inhospital management is expected to lead to more frequent exacerbations and recurrent hospital admission, and is associated with increased mortality. Aims To explore inhospital management of COPD and to compare the results with recommendations from international guidelines. Methods A literature search was carried out for relevant articles published 2000-2009 in the databases Medline, Cochrane Library, Cumulative Index for Nursing and Allied Health Literature and Invert. In addition, the reference lists of the selected articles were examined. Main inclusion criteria were as follows: COPD, exacerbation, hospitalization, description of inpatient management, and clinical trials. Assessment and treatment strategies in different studies were analysed and compared with American Thoracic Society-European Respiratory Society and Global Initiative for Chronic Obstructive Lung Disease guidelines. Outcomes were analysed. Results Seven eligible studies were selected. Non-pharmacological treatment was infrequently explored. When compared with international guidelines, diagnostic assessment and therapy were suboptimal, especially non-pharmacological treatment. Respiratory physicians were more likely to perform recommended interventions than non-respiratory physicians. Conclusions Adherence to international guidelines is low for inhospital management of COPD exacerbations, especially in terms of non-pharmacological treatment. Further investigation is recommended to explore strategies like care pathways that improve performance of recommended interventions.

Predictors of outcome after exacerbation of chronic obstructive pulmonary disease

BACKGROUND

The outcome after hospitalization for an exacerbation of chronic obstructive pulmonary disease (COPD) is unfavorable and uncertainty exists about factors predicting short and long-term prognosis.

OBJECTIVE

To identify clinical predictors of length of hospital stay (LOS) and three-year mortality after COPD exacerbations requiring hospitalization.

DESIGN

Retrospective analysis of prospectively collected data.

PARTICIPANTS AND METHODS

All consecutive patients hospitalized with COPD exacerbation were enrolled. Disease severity was estimated by FEV(1,) body mass index (BMI), Medical Research Council (MRC) chronic dyspnoea scale, previous hospitalizations, need for long-term oxygen treatment (LTOT), arterial oxygen and carbon dioxide partial pressures (PaO(2) and PaCO(2)), pH and respiratory rate. Outcome was assessed by LOS and three-year mortality.

MAIN RESULTS

Out of 81 patients enrolled, three-year mortality data were available for 61. LOS was related to BMI, MRC scale and respiratory rate. Three-year mortality was related to FEV(1), BMI, MRC scale, LTOT, and PaCO(2). Multiple logistic regression analysis demonstrated that MRC scale was the only independent determinant of LOS, [p = 0.001, odds ratio (OR) 7.67 (95% CI 2.50-23.41)], whereas MRC scale and BMI predicted three-year mortality, [p = 0.001, OR 8.28 (95% CI 2.25-30.47) and p = 0.006, OR 6.91 (95% CI 1.74-27.48), respectively]. Cox regression analysis demonstrated identical results. Using receiver-operator-optimized thresholds for these variables (MRC > 2 and BMI < 25 kg/m(2)), we propose a prediction model that accurately determines three-year mortality risk.

CONCLUSIONS

In this study, MRC scale and BMI predicted outcome after COPD hospitalization. Pending further validation, this predictive model may contribute to identify patients with poor outcome even when spirometric data are unavailable.

Defining disease modification in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a debilitating condition characterized by airflow limitation that is not fully reversible. It is a major cause of morbidity and mortality and represents substantial economic and social burden throughout the world. A range of interventions has been developed that decrease symptoms and address complications associated with COPD. However, to date few interventions have been unequivocally demonstrated to modify disease progression. Assessment of the potential for interventions to modify disease progression is complicated by the lack of a clear definition of disease modification and disagreement over appropriate markers by which modification should be evaluated. To clarify these issues, a working group of physicians and scientists from the USA, Canada and Europe was convened. The proposed working definition of disease modification resulting from the group discussions was "an improvement in, or stabilization of, structural or functional parameters as a result of reduction in the rate of progression of these parameters which occurs whilst an intervention is applied and may persist even if the intervention is withdrawn". According to this definition, pharmacologic interventions may be considered disease-modifying if they provide consistent and sustained improvements in structural and functional parameters. Smoking cessation and lung volume reduction surgery would both qualify as disease-modifying interventions.

Characteristics of patients admitted for the first time for COPD exacerbation

BACKGROUND

This study describes the characteristics of a large sample of patients hospitalised for the first time for a chronic obstructive pulmonary disease (COPD) exacerbation.

METHODS

All subjects first admitted for a COPD exacerbation to nine teaching Spanish hospitals during January 2004-March 2006, were eligible. COPD diagnosis was confirmed by spirometry under stability. At admission, sociodemographic data, lifestyle, previous treatment and diagnosis of respiratory disease, lung function and Charlson index of co-morbidity were collected. A comprehensive assessment, including dyspnea, lung function, six-minute walking test, and St. George's Respiratory Questionnaire (SGRQ), was completed 3 months after admission, during a clinically stable disease period.

RESULTS

Three-hundred and forty-two patients (57% of the eligible) participated in the study: 93% males, mean (SD) age 68 (9) years, 42% current smokers, 50% two or more co-morbidities, 54% mild-to-moderate dyspnea, post-bronchodilator FEV(1) 52 (16)% of predicted (54% mild-to-moderate COPD in ATS/ERS stages), 6-min walking distance 440 m, total SGRQ score 37 (18), and 36% not report respiratory disease. The absence of a previous COPD diagnosis, positive bronchodilator test, female gender, older age, higher DLco and higher BMI were independently associated with less severe COPD.

CONCLUSIONS

We show that the patients admitted after presenting with their first COPD exacerbation have a wide range of severity, with a large proportion of patients in the less advanced COPD stages.

[Causes of death and risk factors for mortality in patients with severe chronic obstructive pulmonary disease]

OBJECTIVE

The objective of this study was to assess the causes of death and risk factors for mortality in a cohort of patients with severe chronic obstructive pulmonary disease (COPD).

PATIENTS AND METHODS

We studied 203 patients with severe COPD (forced expiratory volume in 1 second [FEV(1)] <50%), who were attended in our respiratory department day hospital (2001-2006). Clinical variables were recorded on inclusion, and clinical course and causes of death were retrospectively reviewed.

RESULTS

The mean (SD) age of patients was 69 (8) years and the mean FEV(1) was 30.8% (8.2%). One-hundred and nine patients died (53.7%); death was attributed to respiratory causes in 72 (80.9%), with COPD exacerbation being the most frequent specific cause within this category (48.3%). During follow-up, 18.7% required admission to the intensive care unit (ICU). Survival at 1, 3, and 5 years was 80%, 53%, and 26%, respectively. The multivariate analysis showed that mortality was associated with age, stage IV classification according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD), cor pulmonale, and hospital admission during the year prior to inclusion. Need for admission to the ICU during follow-up was a factor independently associated with higher mortality.

CONCLUSIONS

Mortality in patients with severe COPD was high and exacerbation of the disease was one of the most frequent causes of death. Age, GOLD stage, cor pulmonale, prior admission to hospital, and need for admission to the ICU during follow-up were independent predictors of mortality.

C-reactive protein and other predictors of poor outcome in patients hospitalized with exacerbations of chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVE

CRP is elevated in patients with acute exacerbations of COPD (AECOPD), but there is little information on whether this biomarker can help to identify adverse short-term clinical outcomes.

METHODS

A 6-month prospective study of all patients with AECOPD requiring hospital admission. Clinical, laboratory (including plasma CRP levels at admission) and functional data were recorded. The outcome variable (the adverse outcome) consisted of: (i) death in hospital or within 15 days of discharge, (ii) transfer to the intensive care unit, or (iii) development of acute heart failure during hospitalization.

RESULTS

Data from 147 patients with a total of 160 admissions were recorded. During follow up, 38 (23.7%) adverse outcomes were observed, including 13 (8.8%) and 8 (5.4%) patients who died during hospitalization or within 15 days of discharge, respectively. CRP at a level of 50 mg/L was related to an adverse outcome (OR 4.9, 95% CI: 1.92-12.6, P < 0.01), although by itself it was neither sensitive nor specific (area under the receiver operating characteristic curve (AUC) 0.69, 95% CI: 0.60-0.77). However, a risk score derived from the combination of CRP with other variables, such as 'current smoker', 'at least two comorbidities' and 'confusion,' at admission showed good predictive ability to identify an adverse outcome (AUC of 0.80, 95% CI: 0.72-0.88).

CONCLUSIONS

Plasma CRP in combination with other variables obtained at admission may assist identification of high-risk patients with AECOPD.