Physiological and radiological characterisation of patients diagnosed with chronic obstructive pulmonary disease in primary care

Thin-section CT in obstructive pulmonary disease: discriminatory value

PURPOSE

To use thin-section computed tomography (CT) to distinguish between causes of obstructive pulmonary disease, to determine which distinctions give rise to diagnostic imprecision, and to identify the most useful CT features.

MATERIALS AND METHODS

Thin-section CT scans of 105 patients with obstructive pulmonary disease (asthma, n = 35; centrilobular emphysema, n = 30; panlobular emphysema, n = 21; and obliterative bronchiolitis, n = 19) and 33 healthy subjects were assessed independently by two observers. The most likely diagnosis and a confidence rating were assigned. Individual thin-section CT features were recorded. Accuracy, sensitivity, specificity, negative predictive value, and positive predictive value for first-choice diagnoses were calculated. The prevalence of CT features between pairs of conditions was compared with the chi(2) or Fisher exact test as appropriate.

RESULTS

A correct first-choice diagnosis was made in 199 of 276 (72%) observations. A correct first-choice diagnosis was made in 35 of 38 (92%) observations in patients with obliterative bronchiolitis, in 53 of 60 (88%) observations in patients with centrilobular emphysema, in 53 of 66 (80%) observations in healthy subjects, in 37 of 70 (53%) observations in patients with asthma, and in 20 of 42 (48%) observations in patients with panlobular emphysema. The major sources of diagnostic inaccuracy were differentiation between panlobular and centrilobular emphysema, asthma and normality, and asthma and obliterative bronchiolitis. There were significant increases in prevalence of (a) bronchial wall thickening and vascular attenuation in patients with asthma when compared with healthy subjects and (b) vascular attenuation and decreased attenuation in patients with obliterative bronchiolitis when compared with patients with asthma (P <.001).

CONCLUSION

CT helps to distinguish diseases that cause airflow obstruction. Thin-section CT is particularly accurate in the identification of obliterative bronchiolitis.

Recent advances in diagnosis and management of chronic bronchitis and emphysema

Chronic obstructive pulmonary disease is a progressive inflammatory disease of the airways and lung parenchyma. Expiratory airflow limitation is the hallmark of chronic obstructive pulmonary disease. It is a significant cause of morbidity and mortality in the United States and worldwide and results in a large consumption of health care resources. Unfortunately, despite efforts to curb this disease, its prevalence is increasing. The diagnosis is usually made when the patient complains of dyspnea on exertion; by this time, irreversible structural damage to the lung has already occurred. Given the nonspecific symptoms of the disease and the inability to effectively treat and reverse the damage, it is essential to diagnose the disease in its early stages and take the necessary preventive measures, thus avoiding disability or death. This review summarizes the latest developments in the diagnosis and management of chronic obstructive pulmonary disease. The first half of the review discusses functional, radiographic, biochemical, and cellular/histopathologic issues in the diagnosis of chronic obstructive pulmonary disease. The second half focuses on the current pharmacologic and nonpharmacologic advances in chronic obstructive pulmonary disease, including the role of respiratory support and surgical treatment. Based on the research on the cellular mechanisms of chronic obstructive pulmonary disease, the review also makes a reference to novel and experimental therapies for chronic obstructive pulmonary disease.

Management of clinical failures in non-ICU patients with chronic obstructive pulmonary disease exacerbations

Clinical failure after initial treatment for exacerbations of chronic obstructive pulmonary disease (COPD) occurs in 10-25% of cases. Once the original diagnosis is confirmed, there is a need to optimise therapy, including introducing bronchodilators and corticosteroids. The use of aggressive antibiotic treatment is recommended for patients with risk factors (elderly, more than four exacerbations per year, underlying cardiopulmonary disease) and more severe disease. Fluoroquinolones are a good choice for those patients who failed initial therapy and who require antimicrobials, including those with simple exacerbations, complicated cases with comorbidity, or those with bronchiectasis. Consideration of less common pathogens, such as Pseudomonas aeruginosa infection, should also be considered. Bacteria usually associated with exacerbations are becoming increasingly resistant, and this needs to be considered when deciding on appropriate antibiotic treatment.

Changing paradigms in the diagnosis and management of bronchiectasis

The face of bronchiectasis may have changed in recent years but individual cases continue to pose difficult challenges. As childhood infection becomes less of a problem, alternative causes of bronchiectasis are increasingly recognized which themselves offer new problems of diagnosis and management. Evolving concepts of pathogenesis suggest alternative strategies for treatment but as yet the evidence base on which to make firm decisions is lacking. Antibacterial regimens are not universally applicable and individualized protocols with parenteral, nebulized or continuous antibacterial therapy are increasingly used in the treatment of patients with bronchiectasis. Despite the theoretical appeal of using mucolytic or anti-inflammatory drugs their roles are still uncertain and have yet to be examined in adequate clinical trials. The factors determining disease progression are still poorly understood but in some patients worsening airflow obstruction heralds the onset of ventilatory failure. The management of the latter requires bronchodilators and controlled oxygen therapy, and strategies including non-invasive ventilation are increasingly an option. Changing indications for surgery are evident with fewer palliative resections but a developing role for transplantation.

Symptom resolution assessed using a patient directed diary card during treatment of acute exacerbations of chronic bronchitis

BACKGROUND

Acute exacerbations of chronic bronchitis are common and the presenting symptoms vary, although it is not clear how this should influence management. From a health care perspective, an understanding of the speed of symptom resolution is of importance to determine the success of treatment or when a change is indicated because of treatment failure.

METHODS

The response of 63 patients treated at home for exacerbations of chronic bronchitis was assessed using a patient directed diary card incorporating sputum characteristics and symptoms. Treatment was given according to the nature of the sputum at presentation; patients with purulent sputum received an antibiotic for 5 or 10 days (randomised, double blind) whereas patients with mucoid sputum received high dose inhaled steroid or placebo for 14 days (randomised, double blind).

RESULTS

The mean (SE) total diary card score at presentation was significantly higher in the purulent group than in the mucoid group (19.7 (0.9) v 16.3 (0.9); mean difference -3.4 (95% CI -6.1 to -0.7), p<0.05). In the purulent group sputum colour and volume improved rapidly and in both groups the mean (SE) total diary card score had improved by the fifth day of treatment to 13.0 (0.7) in the purulent group (mean difference -6.6 (95% CI -8.8 to -4.4), p<0.001) and 14.6 (0.8) in the mucoid group (mean difference -1.7 (95% CI -4.0 to 0.8), p<0.05), which was no longer significantly different from the stable state. Diary card scores did not differ significantly between patients who received antibiotics for 5 or 10 days in the purulent group or between patients who received inhaled fluticasone or placebo in the mucoid group.

CONCLUSIONS

Exacerbations of chronic bronchitis associated with purulent sputum have significantly worse symptoms at presentation than those with mucoid sputum. In both groups these symptoms resolve rapidly so that by the fifth day of treatment they are no different from the stable state. No significant effect was found on symptom resolution of antibiotic duration (5 v 10 days) in the purulent group or of inhaled fluticasone in the mucoid group, which resolved without antibiotics. Larger numbers may be required to demonstrate a statistically (if not clinically) significant difference.

Obstructive lung diseases: COPD, asthma, and many imitators

Chronic obstructive pulmonary disease (COPD) is a common respiratory disorder that occurs in 10% to 15% of people who smoke, an estimated 16 million Americans. Asthma is also common. Spirometry is generally used to detect early COPD in smokers and to evaluate patients with respiratory symptoms. Although COPD and asthma account for most obstructive lung diseases, a broad spectrum of other disorders, including bronchiectasis, upper airway lesions, bronchiolar diseases, and some interstitial lung diseases, are associated with airflow obstruction. These less common forms of obstructive lung diseases are often misdiagnosed because of their uncommon occurrence and poor recognition. We describe the heterogeneous spectrum of disorders that can present with evidence of airflow obstruction and outline a diagnostic approach to obstructive lung disease.

Changes in bronchial inflammation during acute exacerbations of chronic bronchitis

There are little data describing noncellular changes in bronchial inflammation during exacerbations of chronic bronchitis. The relationship between sputum colour and airway inflammation at presentation has been assessed during an exacerbation in patients with chronic bronchitis and a primary care diagnosis of chronic obstructive pulmonary disease. Sputum myeloperoxidase, neutrophil elastase, leukotriene B4 (LTB4), interleukin-8 (IL-8), sol:serum albumin ratio and serum C-reactive protein were measured in patients presenting with an exacerbation and mucoid (n = 27) or purulent sputum (n = 42). Mucoid exacerbations were associated with little bronchial or systemic inflammation at presentation, and sputum bacteriology was similar to that obtained in the stable state. Purulent exacerbations were associated with marked bronchial and systemic inflammation (p < 0.025 for all features) and positive sputum cultures (90%). Resolution was related to a significant reduction in LTB4 (p < 0.01), but no change in IL-8, suggesting that LTB4 may be more important in neutrophil recruitment in these mild, purulent exacerbations. In the stable state, IL-8 remained higher in patients who had experienced a purulent exacerbation (2p < 0.02). The presented results indicate that exacerbations of chronic bronchitis, defined by sputum colour, differ in the degree of bronchial and systemic inflammation. Purulent exacerbations are related to bacterial infection, and are associated with increased neutrophilic inflammation and increased leukotriene B4 concentrations.

Factors associated with relapse after ambulatory treatment of acute exacerbations of chronic bronchitis. DAFNE Study Group

This study aimed to identify the risk factors for relapse after ambulatory treatment of acute exacerbations of chronic bronchitis (AECB) that can easily be used in a primary care setting. Data were prospectively collected on 2,414 ambulatory patients with AECB from 268 general practices located throughout Spain. A multivariate model to identify risk factors independently associated with failures was developed and validated from the information recorded at the inclusion visit and at 30-days follow-up visit. A total of 507 patients relapsed (21%); of these, 84 required admission (16.5%). The multivariate model for prediction of the risk of relapse included 2,414 cases: 1,689 for the developmental sample and 725 in the validation sample. The model obtained contained three readily-obtainable variables: ischaemic heart disease (odds ratio (OR)=1.63; 95% confidence interval (CI)=1.07-2.47), degree of dyspnoea (OR = 1.31; 1.14-1.50) and number of visits to the general practitioner the previous year (OR = 1.07; 1.04-1.10). The model calibrated well in developmental and validation samples (goodness-of-fit tests: p = 0.295 and p = 0.637, respectively). Severity of the exacerbation was not associated with increased risk of relapse in either univariate or multivariate analysis. The present results suggest that baseline characteristics of the patients such as degree of dyspnoea, coexisting ischaemic heart disease and number of previous visits to the general practitioner for respiratory problems are strongly associated with increased risk of relapse after ambulatory treatment of acute exacerbations of chronic bronchitis. In contrast, exacerbation severity was not associated with clinical failure. Guidelines for management of acute exacerbations of chronic bronchitis should consider such risk factors and advocate intensive broad spectrum treatment and closer follow-up of patients exhibiting them.

Bronchiectasis

Bronchiectasis is a structural derangement of the bronchial wall that is characterized by airway dilatation and bronchial wall thickening. As a result of this abnormality, chronic inflammation and secondary microbial infections occur, which cause additional damage to the bronchi. Recent insights into the potential pathophysiological mechanisms of bronchiectasis, as well as improvements in computed tomography and the development of new pharmacological agents, might help to improve the clinical management of this chronic infective/inflammatory disorder.

Relationship between airway inflammation and the frequency of exacerbations in patients with smoking related COPD

BACKGROUND

Patients with more frequent exacerbations of chronic obstructive pulmonary disease (COPD) may have increased bronchial inflammation. Airway inflammation was measured in patients who had been thoroughly investigated with full pulmonary function testing, thoracic HRCT scanning, and sputum microbiology to examine further the relationship between exacerbation frequency and bronchial inflammation.

METHODS

Airway inflammation (spontaneous sputum sol phase myeloperoxidase (MPO), elastase, leukotriene (LT)B(4), interleukin (IL)-8, secretory leukoprotenase inhibitor (SLPI), protein leakage) and serum levels of C reactive protein (CRP) were compared in 40 patients with stable, smoking related COPD, divided into those with frequent (> or =3/year) or infrequent (< or =2/year) exacerbations according to the number of primary care consultations during the preceding year. The comparisons were repeated after excluding eight otherwise clinically indistinguishable patients who had tubular bronchiectasis on the HRCT scan.

RESULTS

Patients with frequent (n=12) and infrequent (n=28) exacerbations were indistinguishable in terms of their clinical, pulmonary function, and sputum characteristics, CRP concentrations, and all of their bronchial inflammatory parameters (p>0.05). The patients without evidence of tubular bronchiectasis (n=32) were equally well matched but the sputum concentrations of SLPI were significantly lower in the frequent exacerbators (n=8) in this subset analysis (p<0.05).

CONCLUSIONS

There are several clinical features that directly influence bronchial inflammation in COPD. When these were carefully controlled for, patients with more frequent reported exacerbations had lower sputum concentrations of SLPI. This important antiproteinase is also known to possess antibacterial and antiviral activity. Further studies are required into the nature of recurrent exacerbations and, in particular, the regulation and role of SLPI in affected individuals.