***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Background Patients with chronic obstructive pulmonary disease ( COPD ) who are not severely hypoxaemic at rest may experience significant breathlessness on exertion , and ambulatory oxygen is often prescribed in this circumstance despite a lack of conclusive evidence for benefit . This study aim ed to determine whether such patients benefit from domiciliary ambulatory oxygen and , if so , which factors may be associated with benefit . Methods This was a 12 week , parallel , double-blinded , r and omised , placebo-controlled trial of cylinder air versus cylinder oxygen , provided at 6 l/min intranasally , for use during any activity provoking breathlessness . Patients underwent baseline measurements of arterial blood gases and lung function . Outcome measures assessed dyspnoea , health-related quality of life , mood disturbance , functional status and cylinder utilisation . Data were analysed on an intention-to-treat basis , p≤0.05 . Results 143 subjects ( 44 female ) , mean±SD age 71.8±9.8 years , forced expiratory volume in 1 s (FEV1)1.16±0.51 lites , Pao2 9.5±1.1 kPa ( 71.4±8.5 mm Hg ) were r and omised , including 50 patients with exertional desaturation to ≤88 % . No significant differences in any outcome were found between groups receiving air or oxygen . Statistically significant but clinical ly small improvements in dyspnoea and depression were observed in the whole study group over the 12 weeks of the study . Conclusion In breathless patients with COPD who do not have severe resting hypoxaemia , domiciliary ambulatory oxygen confers no benefits in terms of dyspnoea , quality of life or function . Exertional desaturation is not predictive of outcome . Intranasal gas ( either air or oxygen ) may provide a placebo benefit . Clinical trial number ACTRN12605000457640 Pulmonary rehabilitation is beneficial for patients with chronic lung disease . However , long-term maintenance has been difficult to achieve after short-term treatment . We evaluated a telephone-based maintenance program after pulmonary rehabilitation in 172 patients with chronic lung disease recruited from pulmonary rehabilitation graduates . Subjects were r and omly assigned to a 12-month maintenance intervention with weekly telephone contacts and monthly supervised reinforcement sessions ( n = 87 ) or st and ard care ( n = 85 ) and followed for 24 months . Except for a slight imbalance between sexes , experimental and control groups were equivalent at baseline and showed similar improvements after rehabilitation . During the 12-month intervention , exercise tolerance ( maximum treadmill workload and 6-minute walk distance ) and overall health status ratings were better maintained in the experimental group together with a reduction in hospital days . There were no group differences for other measures of pulmonary function , dyspnea , self-efficacy , generic and disease-specific quality of life , and health care use . By 24 months , there were no significant group differences . Patients returned to levels close to but above prerehabilitation measures . We conclude that a maintenance program of weekly telephone calls and monthly supervised sessions produced only modest improvements in the maintenance of benefits after pulmonary rehabilitation Objectives Neuroimaging in chronic breathlessness is challenging . The study objective was to test the feasibility of magnetoencephalography ( MEG ) for functional neuroimaging of people with chronic breathlessness . Design Feasibility pilot study . Setting Respiratory clinic out- patients . Participants 8 patients ( mean age=62 ; ( range 47–83 ) ; 4 men ) with chronic non-malignant lung disease ; modified MRC breathlessness score ≥3 ( median mMRC=4 ) , intensity of exercise-induced breathlessness > 3/10 ; no contraindication to MRI scanning . Methods and measures 4 MEG scans were conducted for each participant : ( 1 ) at rest ( 5 mins ) , ( 2 ) postseated leg exercise-induced breathlessness during recovery ( 10 mins ) . Recovery scans ( 2 ) were conducted with/without facial airflow in r and om order ; both scans were repeated 1 h later . Participants rated breathlessness intensity ( 0–10 Numerical Rating Scale ( NRS ) ) at baseline , maximal exertion and every minute during recovery , and rated acceptability of study procedures at the end of the study ( 0–10 NRS ) . A structural MRI scan was conducted for MEG co registration and source -space analyses . Rest data were compared with data from healthy volunteers ( N=6 ; 5 men ; mean age=30.7 years±3.9 years ) . Results Exercises and MEG scanning were acceptable to all participants ; 7/8 completed the MRI scans . Maximum breathlessness intensity was induced by 5 min ’ exercise . The same level was induced for repeat scans ( median=8 ; IQR=7–8 ) . All recovered to baseline by 10 min . Time-frequency profiles of data from the first and last 3 min were analysed in MEG source space based on breathlessness location estimates . Source localisation was performed , but anatomical source inference was limited to the level of the lobe . Differences in areas of activity were seen : during recovery scans ; with and without airflow ; and between participants /normal volunteers at rest . Conclusions MEG is a feasible method to investigate exercise-induced breathlessness in people breathless with chronic lung disease , and able to identify neural activity related to changes in breathlessness Background Breathlessness is a frequently occurring symptom of cardiorespiratory conditions and is a common cause of emergency department presentation . The aim of this study was to estimate the prevalence of acute-on-chronic breathlessness as a cause for presentation to the major emergencies area of the emergency department . Methods A prospect i ve patient self-report survey and clinical record review of consecutive attendees to the major emergencies area of the emergency department in a single tertiary hospital between 12/5/14 and 29/5/14 was conducted . Eligible patients were clinical ly stable and had mental capacity to provide data . Results There were 2,041 presentations during the study period , of whom 1,345 ( 66 % ) were eligible . There was a 90 % survey response rate ( 1,212/1,345 ) ; 424/1,212 ( 35 % ) self-reported breathlessness most days over the past month of whom 245 gave breathlessness as a reason for this presentation . Therefore , the prevalence of acute-on-chronic breathlessness as a reason to present to the major emergencies area was 20.2 % ( 245/1,212 , 95 % CI 17.9 % to 22.5 % ) . During this period there were 4,692 major and minor presentations ; breathlessness was therefore a cause of at least 5.2 % ( 245/4,692 , 95 % CI 4.6 to 5.9 % ) of all emergency department presentations . Conclusions This study found that one in five ambulance presentations to the ED were due to acute-on-chronic breathlessness .  Most patients had non-malignant underlying conditions , had experienced considerable breathlessness for an extended period , had discussed breathlessness with their GP and presented out of daytime hours . Others were often involved in their decision to present . This represents clinical ly significant burden for patients , their family carers and the emergency health services BACKGROUND In spite of the well-demonstrated benefits for patients with COPD , pulmonary rehabilitation programmes show considerable drop-out and suboptimal attendance rates . The purpose of this prospect i ve study is to examine causes for drop-out and non-attendance during a 12 week multidisciplinary pulmonary rehabilitation programme , and to investigate whether sociodemographic and medical factors as well as patients ' perception of their illness are related to drop-out and non-attendance . METHODS Two hundred and seventeen patients with COPD who were referred to a rehabilitation centre participated in this multicentre study . Prior to treatment , patients received a question naire , which included the Illness Perception Question naire-Revised . Clinical data were drawn from medical records . Drop-out and attendance were recorded during the programme . RESULTS Fifty patients ( 23 % ) did not complete the rehabilitation course , of which half was due to medical reasons ( e.g. exacerbations , hospitalisations ) . Non-completion could not be predicted by baseline sociodemographic , clinical or psychological variables . Patients who declined treatment did not differ from patients who dropped out due to medical reasons . On average , patients attended 92 % of all scheduled appointments . Of all missed appointments , approximately 20 % were accountable to factors beyond patients ' control ( e.g. absent therapists , hospitalisations ) . Smoking , living alone , a lower fat free mass and lower confidence in treatment increased the chance of patients not attending an appointment during rehabilitation . CONCLUSION In general , adherence in rehabilitation is high . However , paying attention to patients ' nutritional status and creating a positive expectation of treatment during referral and intake appear to be important if one aims to optimise patients ' attendance during rehabilitation CONTEXT The h and held fan is an inexpensive and safe way to provide facial airflow , which may reduce the sensation of chronic refractory breathlessness , a frequently encountered symptom . OBJECTIVES To test the feasibility of developing an adequately powered , multicenter , multinational r and omized controlled trial comparing the efficacy of a h and held fan and exercise advice with advice alone in increasing activity in people with chronic refractory breathlessness from a variety of medical conditions , measuring recruitment rates ; data quality ; and potential primary outcome measures . METHODS This was a Phase II , multisite , international , parallel , nonblinded , mixed- methods r and omized controlled trial . Participants were central ly r and omized to fan or control . All received breathlessness self-management/exercise advice and were followed up weekly for four weeks . Participants /carers were invited to participate in a semistructured interview at the study 's conclusion . RESULTS Ninety-seven people were screened , 49 r and omized ( mean age 68 years ; 49 % men ) , and 43 completed the study .  Site recruitment varied from 0.25 to 3.3/month and screening : r and omization from 1.1:1 to 8.5:1 . There were few missing data except for the Chronic Obstructive Pulmonary Disease Self-Efficacy Scale ( two-thirds of data missing ) . No harms were observed . Three interview themes included 1 ) a fan is a helpful self-management strategy , 2 ) a fan aids recovery , and 3 ) a symptom control trial was welcome . CONCLUSION A definitive , multisite trial to study the use of the h and held fan as part of self-management of chronic refractory breathlessness is feasible . Participants found the fan useful . However , the value of information for changing practice or policy is unlikely to justify the expense of such a trial , given perceived benefits , the minimal costs , and an absence of harms demonstrated in this study A r and omized , controlled , single-blind study was performed on 20 patients with chronic obstructive pulmonary disease and exercise-induced hypoxaemia . Ten patients each were r and omly assigned to one of two groups , one training with air and the other training with oxygen . There were no significant differences between the groups regarding values measured prior to the study . The patients trained 3 times per week for 30 minutes each time for a duration of 8 weeks . The training consisted of interval walking on a treadmill ( intensity set according to Borg ratings ) with either air or oxygen administered through a nasal cannula at a rate of 5 l/min . Training significantly improved the 6-minute walking distance by 20 % and 14 % in the air and oxygen group , respectively , when the patients were tested on air . In the same test the air group significantly decreased Borg ratings for perceived exertion . Borg ratings for dyspnoea and perceived exertion significantly decreased in the oxygen group when they were tested on oxygen . It was concluded that oxygen supplementation did not further improve the training effect , compared with training with air , in patients with chronic obstructive pulmonary disease and exercise-induced hypoxaemia BACKGROUND Low-density gas mixtures and oxygen ( O₂ ) supplementation are known to improve physical performance and ventilatory adaptation during incremental maximal exercise in COPD . We investigated whether their combined use during intense physical training is also effective in ameliorating exercise tolerance in patients affected by moderate to severe COPD . METHODS Thirty patients ( FEV₁ < 60 % of predicted ) underwent a 2-month rehabilitation program . Leg-cycle training was conducted thrice weekly at 80 % of the initial peak work rate for at least 20 min breathing room air , a 60 % helium and 40 % O₂ mixture , or supplemental O₂ ( 40 % ) inhaled from a Douglas bag . The study was r and omized with a double-blind design . Before and at the end of the training period the subjects were tested for spirometry , arterial gas tension , diffusing lung capacity for CO , and incremental and constant work rate exercise test on a cycle ergometer . RESULTS Physical training result ed in a significant improvement in peak oxygen consumption and power output ( P < .01 for both ) and in exercise endurance time ( P < .05 ) independently of the kind of inhaled gas during the rehabilitation program ( P ≥ .42 ) . No changes were observed in lung function tests or gas exchange . CONCLUSIONS We concluded that the use of a low-density gas mixture or O₂ supplementation does not contribute to improved exercise performance in patients with moderate to severe COPD without a significantly decreased diffusion lung capacity for CO who are able to tolerate intense physical training Purpose Improving dyspnea and exercise performance are goals of COPD therapy . We tested the hypothesis that air current applied to the face would lessen dyspnea and improve exercise 
    Output:
    
Conclusion : Airflow appears to offer meaningful relief of chronic breathlessness and should be considered as an adjunct treatment in the management of breathlessness