Respiratory Medicine: COPD Update最新文献

Lung volume reduction surgery (LVRS) improves the fit of severely hyperinflated emphysematous lungs to the surrounding chest cavity and thereby improves respiratory mechanics and expiratory airflow. LVRS is a potent and life extending therapy for some patients with severe emphysema and has a low associated operative mortality. The national emphysema treatment trial (NETT) identified characteristics of patients for whom LVRS improves survival, function and health-related quality of life and characteristics of patients who should not have surgery. Patients with upper-lobe predominant distribution of emphysema on high-resolution computed tomogram are most likely to benefit from LVRS vs. optimal medical therapy and rehabilitation. At long-term follow-up, the survival and functional benefits derived from LVRS are durable. In efforts to make lung volume reduction safer and more broadly accessible physician-scientists have developed bronchoscopic lung volume reduction (BLVR) procedures. Early clinical trials of BLVR performed with endobronchial valves (EVB) and sclerosant biogels demonstrate their safety. The ability of BLVR EBV techniques to produce desired atelectasis and lung volume loss is likely limited in those patients with collateral ventilation, incomplete fissures and those unable to achieve complete lobar exclusion. Results from a phase III BLVR EBV trial are in analysis.

Objective

To determine whether clinicians’ prognoses in patients with severe acute exacerbations of obstructive lung disease admitted to intensive care match observed outcomes in terms of survival.

Design

Prospective cohort study.

Setting

92 intensive care units and three respiratory high dependency units in the United Kingdom.

Participants

832 patients aged 45 years and older with breathlessness, respiratory failure, or change in mental status because of an exacerbation of COPD, asthma, or a combination of the two.

Main outcome measures

Outcome predicted by clinicians. Observed survival at 180 days.

Results

517 patients (62%) survived to 180 days. Clinicians’ prognoses were pessimistic, with a mean predicted survival of 49% at 180 days. For the fifth of patients with the poorest prognosis according to the clinician, the predicted survival rate was 10% and the actual rate was 40%. Information from a database covering 74% of intensive care units in the UK suggested no material difference between units that participated and those that did not. Patients recruited were similar to those not recruited in the same units.

Conclusions

Because decisions on whether to admit patients with COPD or asthma to intensive care for intubation depend on clinicians’ prognoses, some patients who might otherwise survive are probably being denied admission because of unwarranted prognostic pessimism.

Reproduced with permission from BMJ Publishing Group Ltd.

The aim of the present study was to determine the external validity of a recently developed questionnaire for the identification of patients at increased risk of airflow limitation in smokers from the general population in the provinces of Dutch and Belgian Limburg (regions surrounding Maastricht, the Netherlands). As part of a study on the early detection of airflow limitation and subsequent smoking cessation treatment (International Standard Randomised Controlled Trial Number: 64481813), the recently developed chronic obstructive pulmonary disease (COPD) diagnostic questionnaire was used in current smokers aged 40–70 yrs, with a smoking history of >or=10 pack-yrs, who reported one or more respiratory symptom (cough, sputum production or dyspnoea), but who had no diagnosis of a respiratory disease (COPD or asthma). Spirometry performed according to American Thoracic Society/European Respiratory Society criteria served as a reference test. Of the 676 subjects who entered the analyses, 398 showed normal lung function and 278 had a diagnosis of COPD (post-bronchodilator forced expiratory volume in one second/forced vital capacity of <0.70). The ability of the COPD diagnostic questionnaire to discriminate between subjects with and without COPD was poor (area under the receiver operating characteristic curve of 0.65). In a high-risk population consisting of middle-aged current smokers with a smoking history of >or=10 pack-yrs, the chronic obstructive pulmonary disease diagnostic questionnaire is probably not useful as a diagnostic tool for the identification of patients with an increased risk of airflow limitation.

Reproduced with permission from European Respiratory Society Journals Ltd.

The present study assessed the impact of computerised spirometry interpretation expert support on the diagnostic achievements of general practitioners (GPs), and on GPs’ decision making in diagnosing chronic respiratory disease. A cluster-randomised controlled trial was performed in 78 GPs who each completed 10 standardised paper case descriptions. Intervention consisted of support for GPs’ spirometry interpretation either by an expert system (expert support group) or by sham information (control group). Agreement of GPs’ diagnoses was compared with an expert panel judgement, which served as the primary outcome. Secondary outcomes were: additional diagnostic test rates; width of differential diagnosis; certainty of diagnosis; estimated severity of disease; referral rate; and medication or nonmedication changes. Effects were expressed as odds ratios (ORs) with 95% confidence intervals (CIs). There were no differences between the expert support and control groups in the agreement between GPs and expert panel diagnosis of chronic obstructive pulmonary disease (OR (95% CI) 1.08 (0.70–1.66)), asthma (1.13 (0.70–1.80)), and absence of respiratory disease (1.32 (0.61–2.86)). A higher rate of additional diagnostic tests was observed in the expert support group (2.5 (1.17–5.35)). Computerised spirometry expert support had no detectable benefit on general practitioners’ diagnostic achievements and the decision-making process when diagnosing chronic respiratory disease.

Reproduced with permission from European Respiratory Society Journals Ltd.

Background

Together with smoking, the lung function attained in early adulthood is one of the strongest predictors of chronic obstructive pulmonary disease. We aimed to investigate whether lung function in early adulthood is, in turn, affected by airway function measured shortly after birth.

Methods

Non-selected infants were enrolled at birth in the Tucson Children's Respiratory Study between 1980 and 1984. We measured maximal expiratory flows at functional residual capacity (Vmax(FRC)) in 169 of these infants by the chest compression technique at a mean of 2.3 months (SD 1.9). We also obtained measurements of lung function for 123 of these participants at least once at ages 11, 16, and 22 years. Indices were forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and forced expiratory flow between 25% and 75% of FVC (FEF25-75), both before and after treatment with a bronchodilator (180 microg of albuterol).

Findings

Participants who had infant Vmax(FRC) in the lowest quartile also had lower values for the FEV1/FVC ratio (−5.2%, p<0.0001), FEF25-75 (−663 mL/s, p<0.0001), and FEV1 (−233 mL, p=0.001) up to age 22, after adjustment for height, weight, age, and sex, than those in the upper three quartiles combined. The magnitude and significance of this effect did not change after additional adjustment for wheeze, smoking, atopy, or parental asthma.

Interpretation

Poor airway function shortly after birth should be recognised as a risk factor for airflow obstruction in young adults. Prevention of chronic obstructive pulmonary disease might need to start in fetal life.

©2007 Published by Elsevier Ltd

Pulmonary emphysema is characterized by persistent inflammation and progressive alveolar destruction. The keratinocyte growth factor (KGF) favorably influences alveolar maintenance and repair and possesses anti-inflammatory properties. We aimed to determine whether exogenous KGF prevented or corrected elastase-induced pulmonary emphysema in vivo. Treatment with 5 mg kg⁻¹ day⁻¹ KGF before elastase instillation prevented pulmonary emphysema. This effect was associated with 1) a sharp reduction in bronchoalveolar lavage fluid total protein and inflammatory cell recruitment, 2) a reduction in the pulmonary expression of the chemokines CCL2 (or monocyte chemoattractant protein-1) and CXCL2 (or macrophage inflammatory protein-2α) and of the adhesion molecules ICAM-1 and VCAM-1, 3) a reduction in matrix metalloproteinase (MMP)-2 and MMP-9 activity at day 3, and 4) a major reduction in DNA damage detected by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) in alveolar cells at day 7. Treatment with KGF after elastase instillation had no effect on elastase-induced emphysema despite the conserved expression of the KGF receptor in the lungs of elastase-instilled animals as determined by immunohistochemistry. In vitro, KGF abolished the elastase-induced increase in CCL2, CXCL2, and ICAM-1 mRNA in the MLE-12 murine alveolar epithelial cell line. We conclude that KGF pretreatment protected against elastase-induced pulmonary inflammation, activation of MMPs, alveolar cell DNA damage, and subsequent emphysema in mice.

Abstract used with permission from the American Physiological Society

Recent data suggest beneficial effects of fiber intake on chronic respiratory symptoms in adults that are independent of antioxidant vitamin intake, but little is known about fiber consumption in relation to lung function and chronic obstructive pulmonary disease (COPD). The authors investigated the association of fiber intake with lung function and COPD in 11,897 US men and women from the Atherosclerosis Risk in Communities study (1987–1989). After control for potential confounders, positive associations were found between lung function and fiber intake from all sources as well as from cereal or fruit alone. Compared with those in the lowest quintile, participants in the highest quintile of total fiber intake had a 60.2-ml higher forced expiratory volume in 1 s (FEV(1)) (p for trend <0.001), 55.2-ml higher forced vital capacity (FVC) (p=0.001), 0.4% higher FEV(1)/FVC ratio (p=0.040), 1.8% higher percent predicted FEV(1) (p<0.001), and 1.4% higher percent predicted FVC (p=0.001). Adjusted odds ratios of COPD for the highest versus lowest quintiles of intake were 0.85 (p=0.044) for total fiber, 0.83 (p=0.021) for cereal fiber, and 0.72 (p=0.005) for fruit fiber. This study provides the first known evidence that dietary fiber is independently associated with better lung function and reduced prevalence of COPD.

Reproduced with permission from Oxford University Press

Background

To assess the efficacy of transcutaneous Pco2 (Ptcco2) measurements for monitoring alveolar ventilation in patients requiring noninvasive positive-pressure ventilation (NPPV).

Methods

In a prospective study on method agreement pairs of Paco2 and Ptcco2 (SenTec Digital Monitor; SenTec AG; Therwil, Switzerland), measurements were performed every 10 min during the establishment of NPPV over a 4-h period in 10 patients (8 patients with COPD) presenting with acute-on-chronic hypercapnic respiratory failure, thus providing 250 pairs of measurement.

Results

Mean (+/−SD) Paco2 decreased from 67.2+/−11.9 mm Hg (Ptcco2, 65.5+/−13.9 mm Hg) to 54.6+/−8.8 mm Hg (Ptcco2, 47.8+/−8.8 mm Hg), and mean pH increased from 7.36+/−0.03 to 7.44+/−0.04. Following Ptcco2 assessment, Ptcco2 in the ensuing 2-min period was the strongest predictor for Paco2 compared to Ptcco2 in the ensuing 5-min period and to real-time measurements. Ptcco2 was highly correlated with Paco2 (r=0.916; p<0.001), as determined by linear regression analysis. The mean difference between Paco2 and Ptcco2 was 4.6 mm Hg, and the limits of agreement (bias +/− 1.96 SDs) ranged from −3.9 to 13.2 mm Hg, following the Bland and Altman analysis. Retrospective drift correction produced an even higher correlation (r=0.956; p<0.001) with lower limits of agreement (−1.7 to 7.5 mm Hg).

Conclusions

Ptcco2 measurements provide a sensitive, continuous, and noninvasive method for monitoring alveolar ventilation in patients who are receiving short-term NPPV therapy. Drift correction of Ptcco2 measurements improves the accuracy of Ptcco2 monitoring compared to the “gold standard” Paco2 assessment. A lag time of approximately 2 min is present for reliable Ptcco2 values compared to Paco2 values. However, individual variance between Paco2 and Ptcco2 cannot be excluded. Trial registration: www.uniklinik-freiburg.de/zks/live/uklregister/Oeffentlich.html Identifier:UKF001271.

©2007 American College of Chest Physicians

Aim

To identify patient needs following discharge from hospital after an exacerbation of COPD.

Methods

Qualitative and semi-quantitative study using home-based structured interviews and focus groups involving 25 COPD patients after hospital discharge. Interviews were performed seven days and three months post-discharge. Quantitative data were analysed using descriptive statistics and were triangulated with the qualitative data from interviews and the focus groups. Results: There were high levels of depression (64%) and anxiety (40%). Feelings of anxiety after discharge were associated with the fear of another “attack” and with uncertainties about social and medical care provision, especially the provision of oxygen.

Conclusions

Interventions to reduce readmission for COPD exacerbations need to consider the psychosocial as well as the medical needs of patients. There appears to be a need for improved hospital discharge procedures and community follow-up-including the provision of pulmonary rehabilitation and encouragement of self-management strategies.

Reproduced with the permission of the General Practice Airways Group