1. |
- Appelberg, Jonas, 1964-, et al.
(author)
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Lung aeration during sleep
- 2007
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In: Chest. - : Elsevier BV. - 0012-3692 .- 1931-3543. ; 131:1, s. 122-129
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Journal article (peer-reviewed)abstract
- Background: During sleep, ventilation and functional residual capacity (FRC) decrease slightly. This study addresses regional lung aeration during wakefulness and sleep. Methods: Ten healthy subjects underwent spirometry awake and with polysomnography, including pulse oximetry, and also CT when awake and during sleep. Lung aeration in different lung regions was analyzed. Another three subjects were studied awake to develop a protocol for dynamic CT scanning during breathing. Results: Aeration in the dorsal, dependent lung region decreased from a mean of 1.14 ± 0.34 mL (± SD) of gas per gram of lung tissue during wakefulness to 1.04 ± 0.29 mL/g during non-rapid eye movement (NREM) sleep (- 9%) [p = 0.034]. In contrast, aeration increased in the most ventral, nondependent lung region, from 3.52 ± 0.77 to 3.73 ± 0.83 mL/g (+ 6%) [p = 0.007]. In one subject studied during rapid eye movement (REM) sleep, aeration decreased from 0.84 to 0.65 mL/g (- 23%). The fall in dorsal lung aeration during sleep correlated to awake FRC (R2 = 0.60; p = 0.008). Airway closure, measured awake, occurred near and sometimes above the FRC level. Ventilation tended to be larger in dependent, dorsal lung regions, both awake and during sleep (upper region vs lower region, 3.8% vs 4.9% awake, p = 0.16, and 4.5% vs 5.5% asleep, p = 0.09, respectively). Conclusions: Aeration is reduced in dependent lung regions and increased in ventral regions during NREM and REM sleep. Ventilation was more uniformly distributed between upper and lower lung regions than has previously been reported in awake, upright subjects. Reduced respiratory muscle tone and airway closure are likely causative factors.
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2. |
- Bakker, M. Els, et al.
(author)
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Assessment of Regional Progression of Pulmonary Emphysema With CT Densitometry
- 2008
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In: Chest. - : Elsevier BV. - 1931-3543 .- 0012-3692. ; 134:5, s. 931-937
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Journal article (peer-reviewed)abstract
- Background: Lung densitometry is an effective method to assess overall progression of emphysema, but generally the location of the progression is not estimated. We hypothesized that progression of emphysema is the result of extension from affected areas toward less affected areas in the lung. To test this hypothesis, a method was developed to assess emphysema severity at different levels in the lungs in order to estimate regional changes. Methods: Fifty subjects with emphysema due to alpha(1)-antitrypsin deficiency (AATD) [AATD deficiency of phenotype PiZZ (PiZ) group] and 16 subjects with general emphysema (general emphysema without phenotype PiZZ [non-.PiZ] group) were scanned with CT at baseline and after 30 months. Densitometry was performed in 12 axial partitions of equal volumes. To indicate predominant location, craniocaudal locallity was defined as the slope in the plot of densities against partitions. Regional progression of emphysema was calculated after volume correction, and its slope identifies the area of predominant progression. The hypothesis was tested by investigating the correlation between predominant location and predominant progression. Results: As expected, the PiZ patients showed more basal emphysema than the non-PiZ group (craniocaudal locality, -40.0 g/L vs -6.2 g/L). Overall progression rate in PiZ patients was lower than in non-PiZ subjects. A significant correlation was found between craniocaudal locality and progression slope in PiZ subjects (R = 0.566, p < 0.001). In the non-PiZ group, no correlation was found. Conclusions: In the PiZ group, the more emphysema is distributed basally, the more progression was found in the basal area. This finding suggests that emphysema due to AATD spreads out from affected areas. (CHEST 2008; 134:931-937)
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4. |
- Duong, MyLinh, et al.
(author)
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Sputum eosinophils and the response of exercise-induced bronchoconstriction to corticosteroid in asthma.
- 2008
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In: Chest. - : Elsevier BV. - 0012-3692 .- 1931-3543. ; 133:2, s. 404-11
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Journal article (peer-reviewed)abstract
- BACKGROUND: The relationship between eosinophilic airway inflammation and exercise-induced bronchoconstriction (EIB), and the response to inhaled corticosteroid (ICS) therapy was examined. METHODS: Twenty-six steroid-naïve asthmatic patients with EIB were randomized to two parallel, double-blind, crossover study arms (13 subjects in each arm). Each arm compared two dose levels of inhaled ciclesonide that were administered for 3 weeks with a washout period of 3 to 8 weeks, as follows: (1) 40 vs 160 microg daily; and (2) 80 vs 320 microg daily. Baseline and weekly assessments with exercise challenge and sputum analysis were performed. RESULTS: Data were pooled and demonstrated that 10 subjects had baseline sputum eosinophilia >or= 5%. Only high-dose ICS therapy (ie, 160 and 320 microg) significantly attenuated the sputum eosinophil percentage. Sputum eosinophil percentage significantly correlated with EIB severity, and predicted the magnitude and temporal response of EIB to high-dose therapy, but not to low-dose therapy (ie, 40 and 80 microg). Low-dose ICS therapy provided a significant reduction in EIB at 1 week, with little additional improvement thereafter, irrespective of baseline sputum eosinophil counts. In contrast, high-dose ICS therapy provided a significantly greater improvement in EIB in subjects with sputum eosinophilia compared to those with an eosinophil count of < 5%. The difference between the eosinophilic groups in the magnitude of improvement in EIB was evident after the first week of high-dose ICS therapy and increased with time. CONCLUSIONS: These results suggest that eosinophilic airway inflammation may be important in modifying the severity of EIB and the response to ICS therapy. Measurements of sputum eosinophil percentage may, therefore, be useful in predicting the magnitude and temporal response of EIB to different dose levels of ICSs. Trial registration: clinicaltrial.gov; Identifier: NCT00525772.
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5. |
- Ehrs, Per-Olof, et al.
(author)
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Brief questionnaires for patient-reported outcomes in asthma : validation and usefulness in a primary care setting
- 2006
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In: Chest. - : Elsevier BV. - 0012-3692 .- 1931-3543. ; 129:4, s. 925-932
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Journal article (peer-reviewed)abstract
- OBJECTIVES AND DESIGN: Health-related quality of life (QoL) instruments are generally used for studies of asthma in specialized settings. For primary care use, there is a need for brief and simple questionnaires for structured patient-reported outcomes. We validated the Mini-Asthma Quality of Life Questionnaire (Mini-AQLQ), using the Asthma Quality of Life Questionnaire with standardized activities (AQLQ[S]) as the "gold standard." The Asthma Control Questionnaire (ACQ) was validated against the symptoms domain of the AQLQ(S). Patients were characterized by the Short Form-36 Health Survey (SF-36). SUBJECTS: One hundred eight patients (68 women) with asthma diagnosed by their physicians from 24 primary care centers completed two visits (2 to 3 months apart). Their mean SF-36 scores were lower than the national norm for all domains. RESULTS: The Mini-AQLQ and ACQ correlated well with the AQLQ(S). Reliability, determined in 57 patients with stable AQLQ(S) scores, was good. Both brief questionnaires detected improvement or deterioration of patients at the group level. Global ratings of disease severity by patients or clinicians correlated poorly with disease-specific QoL scores. CONCLUSIONS: The Mini-AQLQ and ACQ instruments are sufficiently simple and robust to be suitable for research and quality of care monitoring in primary care at the group level. They may, after further validation, even be useful in the management of individual patients.
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- Emmelin, Anders, 1950-, et al.
(author)
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Indoor air pollution : a poverty related cause of mortality among the children of the world
- 2007
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In: Chest. - : Elsevier BV. - 0012-3692 .- 1931-3543. ; 132:5, s. 1615-1623
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Journal article (peer-reviewed)abstract
- This article reviews the research on the relation between indoor air pollution exposure and acute respiratory infection (ARI) in children in developing countries. ARI is a cause of death globally, causing approximately 19% of all deaths before the age of 5 years, according to a World Health Organization estimate. Indoor air pollution from biomass fuels, which is strongly poverty related, has long been regarded as an important risk factor for ARI morbidity and mortality. The empirical base for this view is comparatively narrow, with few empirical studies in relation to the magnitude of the global public health importance of the problem. Most existing reports consistently indicate that indoor air pollution is indeed a risk factor for ARI, but studies are generally small and use indirect indicators of pollution, such as use of biomass fuel or type of stove. Exposure assessment for indoor air pollution in developing countries is recognized as a major obstacle because of high cost and infrastructural limitations to chemical pollution sampling. Use of proxy indicators without measurement support may increase the risk of both misclassification of exposure and of confounding by other poverty-related factors. The issue of sufficient sample size further underlines the need for decisions to invest in this research field. Areas where further research is needed also include exploring qualitatively options for interventions that are culturally and economically acceptable to local communities.
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7. |
- Engström, Gunnar, et al.
(author)
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BP Variability and Cardiovascular Autonomic Function in Relation to Forced Expiratory Volume : A Population-Based Study
- 2009
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In: Chest. - : Elsevier BV. - 0012-3692 .- 1931-3543. ; 136:1, s. 177-183
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Journal article (peer-reviewed)abstract
- Background Cardiovascular autonomic dysfunction is associated with increased incidence of cardiovascular diseases (CVD). This population-based study explored whether low FEV(1) or low vital capacity (VC) is associated with autonomic dysfunction, as measured by the spontaneous heart rate variability (HRV) and systolic BP variability (SBPV). Methods SBPV and HRV were recorded during 5 min of controlled breathing in men and women, aged 70 years. FEV(1) and VC were recorded in 901 subjects. Of them, information on HRV and SBPV was available in 820 and 736 subjects, respectively. Measures of autonomic function, ie, SBPV in the low-frequency (LF) and high-frequency (HF) domains, HRV and baroreceptor sensitivity (BRS), were studied in sex-specific quartiles of FEV1 and VC. Results Low FEV(1) was associated with high SBPV in the HF domain. Mean SBPV-HF was 5.2, 4.5, 4.1 and 3.8 mm Hg, respectively, in subjects with FEV(1) in the first (low), second, third and fourth quartile (trend: p < 0.001). This relationship persisted after adjustments for potential confounding factors. Low VC was significantly associated with high SBPV-HF in the crude analysis, but not after adjustment for confounding factors. Neither FEV(1) nor VC showed any significant relationship with BRS, HRV or SBPV in the LF domain. Conclusion In this population-based study, low FEV(1) was associated with high systolic BP variability in the HF domain. It is suggested that high beat-to-beat variability in BP could contribute to the increased cardiovascular risk in subjects with moderately reduced FEV(1).
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8. |
- García Rodríguez, Luis A, et al.
(author)
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Relationship between gastroesophageal reflux disease and COPD in UK primary care
- 2008
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In: Chest. - : Elsevier BV. - 0012-3692 .- 1931-3543. ; 134:6, s. 1223-1230
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Journal article (peer-reviewed)abstract
- BACKGROUND: Gastroesophageal reflux symptoms may be more common in patients with COPD than in control subjects. The aim of this study was to investigate the relationship between diagnoses of COPD and gastroesophageal reflux disease (GERD) in primary care. METHODS: We used the UK General Practice Research Database to identify a cohort of patients with a first diagnosis of GERD (n = 4,391) and another cohort of patients with a first diagnosis of COPD (n = 1,628) during 1996, which we compared with age-matched and sex-matched comparison cohorts without either diagnosis. We calculated the incidence of a GERD diagnosis among the patients with COPD and control subjects, and of a COPD diagnosis among the patients with GERD and control subjects. We also calculated the relative risk (RR) estimates of these diagnoses using the Mantel-Haenszel test. Risks associated with medication use, comorbidities, and demographic and lifestyle factors were examined using a nested case-control analysis. RESULTS: During the 5-year follow-up, the RR of an incident COPD diagnosis in patients with a diagnosis of GERD was 1.17 (95% confidence interval [CI], 0.91 to 1.49), while the RR of an incident GERD diagnosis among patients with a diagnosis of COPD was 1.46 (95% CI, 1.19 to 1.78). A COPD diagnosis was associated with current or former smoking, prior diagnosis of asthma, or the use of asthma medication. A GERD diagnosis was associated with a prior diagnosis of ischemic heart disease. CONCLUSIONS: Patients with a diagnosis of COPD are at a significantly increased risk of a diagnosis of GERD compared with individuals with no COPD diagnosis.
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9. |
- Geerts, William H., et al.
(author)
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Prevention of venous thromboembolism : American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)
- 2008
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In: Chest. - : Elsevier BV. - 0012-3692 .- 1931-3543. ; 133:6 Suppl, s. 381S-453S
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Research review (peer-reviewed)abstract
- This article discusses the prevention of venous thromboembolism (VTE) and is part of the Antithrombotic and Thrombolytic Therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Grade 1 recommendations are strong and indicate that the benefits do or do not outweigh risks, burden, and costs. Grade 2 suggestions imply that individual patient values may lead to different choices (for a full discussion of the grading, see the "Grades of Recommendation" chapter by Guyatt et al). Among the key recommendations in this chapter are the following: we recommend that every hospital develop a formal strategy that addresses the prevention of VTE (Grade 1A). We recommend against the use of aspirin alone as thromboprophylaxis for any patient group (Grade 1A), and we recommend that mechanical methods of thromboprophylaxis be used primarily for patients at high bleeding risk (Grade 1A) or possibly as an adjunct to anticoagulant thromboprophylaxis (Grade 2A). For patients undergoing major general surgery, we recommend thromboprophylaxis with a low-molecular-weight heparin (LMWH), low-dose unfractionated heparin (LDUH), or fondaparinux (each Grade 1A). We recommend routine thromboprophylaxis for all patients undergoing major gynecologic surgery or major, open urologic procedures (Grade 1A for both groups), with LMWH, LDUH, fondaparinux, or intermittent pneumatic compression (IPC). For patients undergoing elective hip or knee arthroplasty, we recommend one of the following three anticoagulant agents: LMWH, fondaparinux, or a vitamin K antagonist (VKA); international normalized ratio (INR) target, 2.5; range, 2.0 to 3.0 (each Grade 1A). For patients undergoing hip fracture surgery (HFS), we recommend the routine use of fondaparinux (Grade 1A), LMWH (Grade 1B), a VKA (target INR, 2.5; range, 2.0 to 3.0) [Grade 1B], or LDUH (Grade 1B). We recommend that patients undergoing hip or knee arthroplasty or HFS receive thromboprophylaxis for a minimum of 10 days (Grade 1A); for hip arthroplasty and HFS, we recommend continuing thromboprophylaxis > 10 days and up to 35 days (Grade 1A). We recommend that all major trauma and all spinal cord injury (SCI) patients receive thromboprophylaxis (Grade 1A). In patients admitted to hospital with an acute medical illness, we recommend thromboprophylaxis with LMWH, LDUH, or fondaparinux (each Grade 1A). We recommend that, on admission to the ICU, all patients be assessed for their risk of VTE, and that most receive thromboprophylaxis (Grade 1A).
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10. |
- Gustafson, T., et al.
(author)
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Survival of patients with kyphoscoliosis receiving mechanical ventilation or oxygen at home
- 2006
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In: Chest. - : Elsevier BV. - 0012-3692 .- 1931-3543. ; 130:6, s. 1828-33
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Journal article (peer-reviewed)abstract
- BACKGROUND: Home mechanical ventilation (HMV) and long-term oxygen therapy (LTOT) are the two treatment alternatives when treating respiratory insufficiency in patients with kyphoscoliosis. We aimed to study the effect on survival with regard to HMV or LTOT alone in patients with respiratory insufficiency due to kyphoscoliosis. METHODS: Swedish patients with nonparalytic kyphoscoliosis (ie, scoliosis not related to neuromuscular disorders) who started LTOT or HMV between 1996 and 2004 were followed up prospectively until February 14, 2006, with death as the primary outcome. Treatment modality, arterial blood gas levels, the presence of concomitant respiratory diseases, and age were recorded at the onset of treatment. No patient was lost to follow-up. RESULTS: One hundred patients received HMV, and 144 patients received oxygen therapy alone. Patients treated with HMV experienced better survival, even when adjusting for age, gender, concomitant respiratory diseases, and blood gas levels, with a hazard ratio of 0.30 (95% confidence interval, 0.18 to 0.51). CONCLUSION: The survival of patients with kyphoscoliosis receiving HMV was better than that of patients treated with LTOT alone. We suggest HMV and not oxygen therapy alone as the primary therapy for patients with respiratory failure due to kyphoscoliosis, regardless of gender, age, and the occurrence of concomitant respiratory diseases.
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