Chronic Respiratory Disease

The aim of this study was to evaluate the relationship between dyspnea and functional, psychosocial and quality of life parameters among persons with chronic obstructive pulmonary disease (COPD). We conducted a cross-sectional study of 90 stable COPD patients recruited from a specialized respiratory clinic. Dyspnea was measured using the ATS-DLD-78 questionnaire modified dyspnea scale (1- 5 scale).Physical and functional evaluation included spirometry and six minute walking tests. Subjects then completed five psychological questionnaires: the Coping Inventory for Stressful Situations, the State/Trait Anxiety Inventory, the Beck Depression Index, the NEO-Five Factor Personality Inventory,and the Interpersonal Relationships Inventory. Patients also completed two disease-specific health related quality of life (HRQL) questionnaires: St. George's Respiratory Questionnaire (SGRQ) and Chronic Respiratory Questionnaire (CRQ). Subjects were predominantly male (n = 65) with a meanage of 68 years (standard deviation 7.6). Over half (54%) the patients reported severe dyspnea (grade 5), and a quarter (24%) reported moderate dyspnea (grade 3-4). Mean FEV₁ was 37.8 ± 14.8% predicted. The mean total SGRQ score was 49 ± 16 and the CRQ total score was 4.2 ± 0.9. Dyspnea severity was associated with poorer HRQL scores and decreased physical performance. Based on linear regression, dyspnea scores - but not spirometric values - also correlated with indices of anxiety, depression, and neuroticism. Dyspnea correlated more strongly with HRQL and with indices of anxiety and depression than spirometric values.Although spirometry is often used to evaluate disease severity, dyspnea which is a patient centered outcome better reflect overall disease impact among COPD patients.

Background: Historical wisdom has recommended up to 50 ft (15.24 m) of tubing based on the oxygen cylinder delivery system. Yet, many individuals may store their stationary systems in one area of the home and conduct their activities at distances by adding additional tubing. The aim of this study was to discriminate at what lengths clinically relevant decreases in flow greater than 20% occurred. Methods: Plastic tubing was added at 25 ft (7.62 m)intervals connected via a swivel adapter up to 200 ft (60.96 m) to a cylinder, concentrator and liquid stationary oxygen system to simulate a home oxygen environment. Flowsof 1-5 L/min were set then measured via the Timemeter 200 after each segment of additional tubing. Results: Output from the cylinder with regulator/flowmeter was greatly diminished as tubing and flowrate was increased which resulted in clinically significant reductions in flow at 2 L/min for tubing lengths greater than 100 ft (30.48 m). The oxygen concentrator had little flow reduction at 1 or 2 L and more flow loss at higher tubing lengths with 3, 4 and 5 L/min. Liquid oxygen was only mildly reduced at 125 ft(38.10 m) of tubing and 4 or 5 L of flow. Neither the concentrator nor liquid oxygen delivery units had flow reductions greater than 13.5 and 4.0%, respectively, at 2 L/min with 200 ft (60.96 m) of tubing. Summary and Recommendations: Tubing length up to 200 ft (60.96 m) could be utilized for providing patient home oxygen with Puritan Bennett style liquid oxygen. We recommend consideration of tubing lengths up to 200 ft (60.96 m) and up to 3 L/min or 100 ft (30.48 m) at 4-5 L/min for Invacare 5 and similar oxygen concentrators; however flow delivery should be verified by the manufacturer. The cylinder regulator/flowmeter system suffered the greatest flow loss. Flows of 1-2 L/min can be clinically maintained with up to 100-ft (30.48 m) oftubing. This study brings clarity of when tubing can be lengthened which may enhance movement within the home and lessen constraints.

Manual lung hyperinflation (MHI) can enhance secretion clearance, improve total lung/thorax compliance and assistin the resolution of acute atelectasis. To enhance secretion clearance in the intubated patient, the evidence highlights the need to maximize expiratory flow. Chronic pulmonary diseases such as chronic obstructive pulmonary disease(COPD) have often been cited as potential precautions and/or contra-indications to the use of manual lung hyperinflation (MHI). There is an absence of evidence on the effects of MHI in the patient with COPD. Research on the effects of mechanical ventilation in the patient with COPD providesa useful clinical examination of the effect of positive pressure on cardiac and pulmonary function. The potential effects of MHI in the COPD patient group were extrapolated on the basis of the MHI and mechanical ventilation literature. There is the potential for MHI to have both detrimental and beneficial effects on cardiac and pulmonary functionin patients with COPD. The potential detrimental effects of MHI may include either, increased intrinsic peep throughinadequate time for expiration by the breath delivery rate, tidal volume delivered or through the removal of appliedextemal PEEP thereby causing more dynamic airway compression compromising downward expiratory flow, which may also retard bronchial mucus transport. MHI may also increase right ventricular after load through raised intrathoracic pressures with lung hyperinflation, and may therefore impair right ventricular function in patients with evidence of cor pulmonale. There is the potential for beneficial effectsfrom MHI in the intubated COPD patient group (i.e., secretion clearance), but further research is required, especially on the effect of MHI on inspiratory and expiratory flowrate profiles in this patient group. The more controlled delivery of lung hyperinflation through the use of the mechanical ventilator may be a more optimal means of providinglunghyperinflation and shouldbe furtherinvestigated.

Patients with cystic fibrosis (CF) are susceptible to chronic respiratory infection with a number of bacterial pathogens. The Burkholderia cepacia complex bacteria are problematic CF pathogens because (i) they are very resistant to antibiotics, making respiratory infection difficult to treat and eradicate; (ii) infection with these bacteria is associated with high mortality in CF; (iii) they may spread from one CF patient to another, leading to considerable problems for both patients and carers; and (iv) B. cepacia complex bacteria are difficult to identify and nine new species have now been found to constitute isolates originally identified as ‘B. cepacia’ based on their phenotypic properties. Here we review the changes that have occurred in the taxonomy of the B. cepacia complex and the pathogenic factors these bacteria possess. While the taxonomy of the B.cepacia complex has advanced considerably with the development of accurate methods for their identification, the pathogenic mechanisms employed by these CF pathogens are only just beginning to be explored at the molecular level. Several virulence factors have been defined for B. cenocepacia (the dominant CF pathogen within the complex); however, knowledge of the disease mechanisms employed by other B. cepacia complex species is limited. The recent determination of the complete genome sequences for several of the B. cepacia complex species should greatly enhance our ability to study these problematic CF pathogens.