***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: Long-term treatment of chronic bronchitis with chest physiotherapy with or without positive expiratory pressure ( PEP ) by mask was studied in 43 patients r and omly allocated to PEP treatment ( PEP group , 20 patients ) and conventional chest physiotherapy ( control group , 23 patients ) . After instruction , the treatments were self-administered twice daily for 12 months ( 34 patients ) and 5 months ( 9 patients ) . Twice weekly , patients filled in a diary concerning symptoms . The PEP group had significantly less cough and less mucus production . The number of acute exacerbations were calculated from the diaries and were lower in the PEP group compared to the control group , and 85 percent of the patients in the PEP group were free from acute exacerbations versus 48 percent in the control group . The PEP group also used less antibiotics and mucolytics . The PEP group had a small increase in FEV1 of mean 62 ml compared to a small decrease of 43 ml for the control group . Treatment with a simple PEP device can reduce morbidity in patients with chronic bronchitis and may preserve lung function from a more rapid decline The purpose of this study was to assess the effects of a particular breathing pattern training ( BPT ) on forced expiratory volume during the first second ( FEV1 ) and forced vital capacity ( FVC ) in patients with chronic obstructive pulmonary disease ( COPD ) . The subjects adjusted each breath to a target breath displayed on a video screen , by using visual feedback . This target was chosen in an individual sample recorded at rest . We used a r and omized , controlled group design . Twenty patients with stable COPD , FEV1 less than 1.5 liters , undergoing a traditional rehabilitation program were r and omly assigned to the  BPT  group or to the control group . Each BPT  subject underwent 30–35 training sessions spread out over four weeks , in addition to the traditional program . FEV1 and FVC were performed before and after this program . ANOVAs showed that FEV1 and FVC significantly improved in BPT subjects , with a mean percent increase of 22 % and 19 % , respectively . Corresponding changes in controls were not significant . This study showed short-term increases in FEV1 and FVC in COPD patients practicing BPT  in addition to respiratory rehabilitation , in comparison with controls . Further studies should incorporate outcome data to clarify the mechanisms and the duration of this effect OBJECTIVE : To investigate the feasibility and the cardiorespiratory effects of using positive expiratory airway pressure , a physiotherapeutic tool , in comparison with a T-tube , to wean patients from mechanical ventilation . METHODS / DESIGN : A prospect i ve , r and omized , cross-over study . SETTING : Two intensive care units . PATIENTS AND INTERVENTIONS : We evaluated forty patients who met weaning criteria and had been mechanically-ventilated for more than 48 hours , mean age 59 years , including 23 males . All patients were su bmi tted to the T-tube and Expiratory Positive Airway Pressure devices , at 7 cm H2O , during a 30-minute period . Cardiorespiratory variables including work of breathing , respiratory rate ( rr ) , peripheral oxygen saturation ( SpO2 ) , heart rate ( hr ) , systolic , diastolic and mean arterial pressures ( SAP , DAP , MAP ) were measured in the first and thirtieth minutes . The condition was analyzed as an entire sample set ( n=40 ) and was also divided into subconditions : chronic obstructive pulmonary disease ( n=14 ) and non-chronic obstructive pulmonary disease ( non- chronic obstructive pulmonary disease ) ( n=26 ) categories . Comparisons were made using a t-test and Analysis of Variance . The level of significance was p < 0.05 . RESULTS : Our data showed an increase in work of breathing in the first and thirtieth minutes in the EPAP condition ( 0.86± 0.43 and 1.02±1.3 ) as compared with the T-tube condition ( 0.25±0.26 and 0.26±0.35 ) ( p<0.05 ) , verified by the flow-sensor monitor ( values in J/L ) . No statistical differences were observed when comparing the Expiratory Positive Airway Pressure and T-tube conditions with regard to cardiorespiratory measurements . The same result was observed for both chronic obstructive pulmonary disease and non- chronic obstructive pulmonary disease subconditions . CONCLUSIONS : Our study demonstrated that , in weaning patients from mechanical ventilation , the use of a fixed level of Expiratory Positive Airway Pressure caused an increase in work of breathing that was not accompanied by any other significant cardiorespiratory changes . Therefore , we have to be cautious when using Expiratory Positive Airway Pressure as a physiotherapeutic tool during weaning from mechanical ventilation On theoretical grounds it is assumed that positive expiratory pressure mask physiotherapy ( PEP ) as a means of promoting mucus clearance is especially effective in the more distal airways . In a r and omized cross-over trial including a control measurement the effect of PEP and of the forced expiration technique combined with postural drainage ( FET/PD ) on regional lung clearance was evaluated in seven patients with chronic bronchitis and abundant sputum production ( mean 32 g.day-1 ) .  PEP consisted of positive expiratory pressure mask breathing interspersed with breathing exercises , forced expiration manoeuvres ( huffing ) and , if necessary , coughing . FET consisted of breathing exercises , huffing and also , if necessary , coughing . FET was combined with PD . Following inhalation of a radio-aerosol  regional lung clearance was estimated by means of gamma camera imaging . The results after PEP appeared to be not significantly different from control . The mean clearance in all three lung zones ( peripheral , intermediate and inner ) was largest after FET/PD as compared with PEP and control . Statistical significance ( p less than 0.02 ) was reached only for clearance in the inner region . It is concluded that PEP has no demonstrable effect on regional lung clearance in these patients Intrapulmonary percussive ventilation ( IPV ) is a ventilatory technique that delivers bursts of high-flow respiratory gas into the lung at high rates , intended for treating acute respiratory failure and for mobilization of secretions . We performed a study , aim ed at assessing the physiological response to IPV , on patients ' breathing pattern , inspiratory effort , lung mechanics and tolerance to ventilation . Ten COPD patients underwent r and omized trials of IPV through a face mask at different pressure/frequency combinations ( 1.2 bar/250 cycles/min ; 1.8/250 ; 1.2/350 ; 1.8/350 ) , separated by return to baseline ( SB ) , using the IMP2 ventilator . In 5 patients we have also compared the physiological changes of IPV with those obtained during pressure support ventilation ( PSV ) .  Minute ventilation did not vary among the trials , but tidal volumes ( VT ) were significantly greater during 1.2/250 , 1.2/350 and 1.8/350 compared to SB . The pressure time product of the diaphragm per minute ( PTPdi/min ) estimate of the diaphragm oxygen expenditure was also significantly reduced during 1.2/250 and 1.8/250 ( 209 cmH2O x s/min for SB vs. 143 and 125 for 1.2/250 and 1.8/250 , respectively P < 0.05 ) , as well as dynamic intrinsic end-expiratory pressure ( PEEPi , dyn ) . Similar reduction in PTPdi/min were obtained also during PSV . Tolerance to ventilation and oxygen saturation were satisfactory and did not change during the different trials . In 5 normal subjects a prolonged apnea trial lasting > 2 min was also performed , without any significant decrease in SaO2 or subjective discomfort . In conclusion , IPV was able to guarantee an adequate ventilation , while inducing a significant unloading of the diaphragm during the " low-frequency " trials The relative value of chest physiotherapy ( including cough ) and cough alone for the removal of excessive tracheobronchial secretions has been assessed in six patients with stable chronic obstructive lung disease . After labelling with inhaled radioactive tracer particles , clearance of secretions from selected central and peripheral lung regions was followed with a gamma camera linked to a computer . Cough alone and chest physiotherapy ( including cough ) were equally effective in the enhancement of central lung clearance .  Physiotherapy but not cough along accelerated peripheral lung clearance ( p less than 0.05 ) . Sputum yield was greater during physiotherapy than during cough ( p less than 0.05 ) . These findings confirm the value of chest physiotherapy and high-light the limitation of cough in patients with excessive tracheobronchial secretion and impaired mucociliary clearance UNLABELLED The efficacy of respiratory physiotherapy by combined-PEP ( RC-Cornet(R ) in combined-PEP-position ) was evaluated in a long-term study with the following set up . STUDY DESIGN R and omized prospect i ve clinical trial over 2 years in 50 patients with severe COPD ( 12 f , 38 m , 63,1 y , FEV 1 41 % , DLCO 51 % of the normal ) . Patients were without infection and exsmokers at begin of the trial . One group was treated only by drug therapy ( theophylline , salmeterol , ipratropiumbromide , systemic steroids 5 mg prednisolone equivalent ) . The second group received the same drug therapy plus physical therapy with the RC-Cornet(R ) ( oscillating PEP ; in combined PEP-position ) 3 times daily at least for 5 minutes or whenever needed . Lung function data were controlled every 3 month during first year and every 4 month in the second year . The compliance was checked by theophylline and cortisol blood levels , inspection of the functionality of the RC-Cornet(R ) and by question ing the patient about compliance with the therapy . RESULTS TGV ( % of normal ) and airway resistance ( measured by bodyplethysmography ) decreased significantly in contrast to the " mere " drug therapy ( p < 0.0177 , p < 0.0179 ) . VC ( % of normal ) increased significant p < 0.0179 in the RC-Cornet(R ) therapy group . In this group significantly less patients ( 13/24 ) needed antibiotics in comparison to the " mere " drug group ( Chi-Quadrat p < 0.0004 ) . Also the need for hospital care was significantly less in the RC-Cornet(R ) group ( 5/12 ) in comparison to the drug therapy group ( Chi-Quadrat < 0.000765 ) . The length of hospital stay in the two groups was not significantly different : 16.2 + /- 6.3 days in the RC-Cornet(R)-group and 18.3 + /- 4.7 days in the drug therapy-group . CONCLUSION This study proves the efficacy of respiratory physiotherapy with combined-PEP in addition to drug therapy in the management of COPD - patients QUESTION Does a new positive expiratory pressure device ( conical-PEP ) decrease lung hyperinflation during exercise in patients with chronic obstructive pulmonary disease compared to normal breathing ? Does it increase the duration of exercise ? DESIGN A r and omised , cross-over trial with concealed allocation . PARTICIPANTS Thirteen patients with moderate to severe chronic obstructive pulmonary disease ( mean FEV1 61 % predicted ) . INTERVENTION THE experimental intervention was conical-PEP breathing with a positive expiratory pressure of 4 - 20 cmH2O during 30 % of 1 RM alternate knee extension exercise at 70 % age-predicted HRmax to fatigue . The control intervention was normal breathing . OUTCOME MEASURES Total lung capacity ( inspiratory capacity and slow vital capacity ) , breathlessness , and leg discomfort were measured pre and post exercise . Cardiorespiratory function was measured pre and during the last 30 s of exercise . Duration of exercise was recorded . RESULTS After the experimental intervention , inspiratory capacity increased 200 ml ( 95 % CI 0 to 400 ) and slow vital capacity increased 200 ml ( 95 % CI 0 to 400 ) more than the control intervention . Participants exercised for 107 s ( 95 % CI -23 to 238 ) more during the experimental intervention than the control intervention . Conical-PEP breathing during exercise result ed in 6.1 fewer breaths/min ( 95 % CI 1.4 to 10.8 ) than normal breathing ; it did not have any adverse effects on CO2 retention or oxygen saturation . CONCLUSION The novel conical-PEP device decreases lung hyperinflation , is safe to use , and tends to increase the duration of exercise . TRIAL REGISTRATION NCT00741832 OBJECTIVE To compare the short-term effects of postural drainage ( PD ) , oscillating positive expiratory pressure ( using the FLUTTER device ) , and expiration with the glottis open in the lateral posture ( ELTGOL ) on oxygen saturation , pulmonary function , and sputum production in patients with an acute exacerbation of chronic bronchitis . DESIGN A prospect i ve , r and omized study . SETTING A clinical ward . PATIENTS Ten patients with chronic bronchitis exacerbation received PD , FLUTTER , and ELTGOL by the same respiratory therapist at about the same time of day on separate days and in r and om order . MAIN OUTCOME MEASURES Oxygen saturation and 
    Output:
    
Evidence from this review indicates that airway clearance techniques are safe for individuals with COPD and confer small beneficial effects on some clinical outcomes .
Consideration may be given to the use of airway clearance techniques for patients with COPD in both acute and stable disease , however current studies suggest that the benefits achieved may be small