***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: We studied the acute effects of 4 different chest physical therapy regimens using a r and omised cross-over design in 14 patients with cystic fibrosis . Treatment A consisted of postural drainage , percussion and vibration ; treatment B of postural drainage and periodic application of a face mask with positive expiratory pressure ( PEP ) ; treatment C of PEP in the sitting position ; treatment D of the forced expiration technique in the sitting position . In terms of sputum expectorated , treatments B and C were superior to treatment D and especially to treatment A ( p less than 0.05 ) . Skin oxygen tension , PSO2 was monitored continuously during and for 35 min after treatment . A substantial and prolonged decay in PSO2 was observed during treatment A , quite different from other patterns seen . During and even following treatment C , an increase in PSO2 was noted . PEP was well accepted by the patients , who preferred treatment C , and we suggest it is incorporated in chest physical therapy regimens if the therapeutic objective is to increase expectoration It has previously been shown that unproductive coughing in both healthy subjects and patients with airways obstruction is not effective in clearing lung secretions . This study investigates the regional mucus transport in a group of subjects with airways obstruction who failed to expectorate following instructed  cough and forced expiration technique . Fourteen patients ( mean + /- SEM age : 68 + /- 2 years ) with airways obstruction ( mean + /- SEM percent predicted . FEV1 : 54 + /- 5 ; daily wet weight sputum : 9.1 + /- 2.0 g ) took part in the study which was a r and omized , three-way crossover within-patient design . Each patient underwent three treatment maneuvers : control , cough ( 30 coughs over a 10-min period ) , and forced expiration ( 30 forced expirations over a 10-min period ) . An objective radioaerosol technique was used to monitor regional mucus movement within the lungs of the patients . The lungs were divided arbitrarily into four regions of interest : tracheal , inner , intermediate , and outer . Peak expiratory flow rate during cough and forced expiration was measured at the mouth . There was no correlation between the radioaerosol clearance from all regions and ( 1 ) mean peak flow during cough and forced expiration , and ( 2 ) mean 24-h sputum production prior to the study day . There were no differences in regional radioaerosol clearance between cough and forced expiration . However , both cough and forced expiration result ed in significant clearance compared with control for all regions with the exception of the forced expiration in the outer region . To our knowledge , this study is the first to demonstrate that unproductive cough and forced expiration result in movement of secretions proximally from all regions of the lung in patients with airways obstruction Background High frequency chest wall oscillation ( HFCWO ) is st and ard treatment for airway clearance in the USA and has recently been introduced in the UK and Europe . There is little published research comparing HFCWO with airway clearance techniques ( ACTs ) frequently used in the UK and Europe . The aim of this study was to compare the short-term effects of HFCWO with usual ACTs in patients with cystic fibrosis hospitalised with an infective pulmonary exacerbation . Methods A 4-day r and omised crossover design was used . Patients received either HFCWO on days 1 and 3 and usual ACTs on days 2 and 4 or vice versa . Wet weight of sputum , spirometry and oxygen saturation were measured . Perceived efficacy , comfort , incidence of urinary leakage and preference were assessed . Data were analysed by mixed model analysis . Results 29 patients ( 72 % male ) of mean ( SD ) age 29.4 ( 8.4 ) years and mean ( SD ) forced expiratory volume in 1 s ( FEV1 ) percentage predicted ( FEV1 % ) 38 ( 16.7 ) completed the study . Significantly more sputum was expectorated during a single treatment session and over a 24 h period ( mean difference 4.4 g and 6.9 g , respectively ) with usual ACTs than with HFCWO ( p<0.001 ) . No statistically significant change in FEV1 % or oxygen saturation was observed after either HFCWO or usual ACTs compared with baseline . 17 patients ( 55 % ) expressed a preference for their usual ACT . Conclusions During both a finite treatment period and over 24 h , less sputum was cleared using HFCWO than usual ACT . HFCWO does not appear to cause any adverse physiological effects and may influence adherence The Flutter VRP1 ( Flutter ) is cl aim ed to increase the clearance of excess bronchial secretions and to improve lung function and oxygenation , but these cl aims were based on computer models , laboratory assisted experiments and uncontrolled clinical trials . A prospect i ve r and omized clinical trial was undertaken , in subjects with cystic fibrosis , using the active cycle of breathing techniques as the ' gold st and ard ' . The cl aims could not be substantiated and the possibility of sputum retention was of concern when the Flutter was used as significantly more sputum ( P < 0.001 ) was cleared with the active cycle of breathing techniques alone . There were no significant changes in lung function or oxygenation Chest physiotherapy is an essential part of the management of cystic fibrosis , yet comparatively few studies have investigated the commonly used forms of chest physiotherapy during acute respiratory exacerbations . Fifteen subjects with cystic fibrosis and predominantly mild pulmonary impairment completed a r and omised cross-over trial with 24 hours between treatments . The active cycle of breathing techniques ( ACBT ) assisted by a physiotherapist was compared with the ACBT performed independently by the patient . Measurement outcomes included pulmonary function tests , indirect calorimetry and oximetry parameters . Energy expenditure was not significantly different between the two treatment regimens , though significant improvements in pulmonary function were apparent 24 hours following the therapist-assisted ACBT . In this group of subjects , neither form of treatment proved superior in terms of energy consumption , but a reduction in airways obstruction was observed as a carry-over effect following the therapist-assisted ACBT BACKGROUND --In vitro studies have suggested that both the viscoelastic properties of lung secretions and the peak flow attained during simulated cough influence clearance . This study examines the possible association of the viscoelastic properties of sputum and maximum expiratory flow with measured effectiveness of mucus clearance induced by instructed cough and by forced expiration technique ( FET ) in patients with airways obstruction . METHODS --Nineteen patients ( 11 men and eight women ) of mean ( SE ) age , % predicted FEV1 , and daily sputum wet weight of 64 ( 2 ) years , 52 (6)% , and 37.5 ( 7.9 ) g respectively participated in the study . Mucus movement from proximal and peripheral lung regions was measured by an objective non-invasive radioaerosol technique . Each patient underwent three assessment s : control , cough , and FET . During cough and FET , maximum expiratory flow was measured at the mouth level . Apparent viscosity and elasticity of the expectorated sputum sample s were measured with a viscometer . RESULTS --Compared with the control run ( mean ( SE ) clearance : 16 (3)% ) there was an increase in clearance from the whole lung during cough ( 44 (5)% ) and FET ( 42 (5)% ) , and also an enhanced clearance of inhaled , deposited radioaerosol from the trachea , inner and intermediate regions of the lungs , but not from the outer region . There were , however , no differences in regional clearance between cough and FET . Neither regional nor total clearance correlated with maximum expiratory flow , apparent viscosity , elasticity , or daily sputum wet weight . CONCLUSIONS --These results confirm that cough and FET both promote effective clearance but suggest that , unlike in vitro studies , sputum production and viscoelasticity , as well as maximum expiratory flow , provide no guide to clearance efficacy in humans We studied the effectiveness of some of the components of a physiotherapy regimen on the removal of mucus from the lungs of 6 subjects with cystic fibrosis . On 5 r and omized study days , after inhalation of a 99mTc-human serum albumin aerosol to label primarily the large airways , the removal of lung radioactivity was measured during 40 min of ( a ) spontaneous cough while at rest ( control ) , ( b ) postural drainage , ( c ) postural drainage plus mechanical percussion , ( d ) combined maneuvers ( postural drainage , deep breathing with vibrations , and percussion ) administered by a physiotherapist , ( e ) directed vigorous cough . Measurements continued for an additional 2 h of quiet rest . Compared with the control day , all forms of intervention significantly improved the removal of mucus : cough ( p less than 0.005 ) ,  physiotherapy maneuvers ( 0.005 less than or equal to p less than 0.01 ) ,  postural drainage  ( p less than 0.05 ) , and  postural drainage plus percussion  ( p less than 0.01 ) . However , there was no significant difference between regimented cough alone and therapist-administered combined maneuvers , nor between  postural drainage  alone and with  mechanical percussion . We conclude that in cystic fibrosis , vigorous , regimented cough sessions may be as effective as therapist-administered physiotherapy in removing pulmonary secretions .  Postural drainage , although better than the control maneuver , was not as effective as cough and was not enhanced by mechanical percussion . Frequent , vigorous self-directed cough sessions are potentially as useful as more complex measures for effective bronchial toilet Background : Chest physiotherapy is essential to the management of cystic fibrosis ( CF ) . However , respiratory muscle fatigue and oxygen desaturation during treatment have been reported . The aim of this study was to determine whether non-invasive ventilation ( NIV ) during chest physiotherapy could prevent these adverse effects in adults with exacerbations of CF . Methods : Twenty six patients of mean ( SD ) age 27 ( 6 ) years and forced expiratory volume in 1 second ( FEV1 ) 34 (12)% predicted completed a r and omised crossover trial comparing st and ard treatment ( active cycle of breathing technique , ACBT ) with ACBT + NIV .  Respiratory muscle strength ( PImax , PEmax ) , spirometric parameters , and dyspnoea were measured before and after treatment . Pulse oximetry ( Spo2 ) was recorded during treatment . Sputum production during treatment and 4 and 24 hours after treatment was evaluated . Results : There was a significant reduction in PImax following st and ard treatment that was correlated with baseline PImax ( r=0.73 , p<0.001 ) . PImax was maintained following NIV ( mean difference from st and ard treatment 9.04 cm H2O , 95 % confidence interval ( CI ) 4.25 to 13.83 cm H2O , p=0.006 ) . A significant increase in PEmax was observed following the NIV session ( 8.04 cm H2O , 95 % CI 0.61 to 15.46 cm H2O , p=0.02 ) . The proportion of treatment time with Spo2 ⩽90 % was correlated with FEV1 ( r=−0.65 , p<0.001  ) . NIV improved mean Spo2 ( p<0.001 ) and reduced dyspnoea ( p=0.02 ) . There were no differences in FEV1 , forced vital capacity ( FVC ) or sputum weight , but FEF25–75 increased following NIV ( p=0.006 ) . Conclusion : Reduced inspiratory muscle strength and oxygen desaturation during chest physiotherapy are associated with inspiratory muscle weakness and severity of lung disease in adults with exacerbations of CF . Addition of NIV improves inspiratory muscle function , oxygen saturation and small airway function and reduces dyspnoea The aim of the study was an estimation of effectiveness of selected autodrainage methods used in the treatment of children with cystic fibrosis and an assessment of patients ' preference in relation to investigated methods . We also estimated the patients and their families ' relation to chest physiotherapy methods , which have been used at home for many years . We studied 17 patients , aged 10 - 18 ( x 13.35 ) , who were hospitalised in the Institute of Mother and Child Paediatric Clinical Dept . We compared four autodrainage methods : 1- force expiratory technique , 2- Flutter(R ) , 3- Flutter ( R ) with relaxation , 4- PEP system . Every investigated drainage methods were tested by each patient according to a determined procedure . The following indices were measured : weight of coughed up sputum , oxygen saturation ( SaO2 ) before , during and after drainage , peak expiratory flaw ( PEF ) before and after drainage . Patients ' relation to autodrainage methods was estimated on the ground of their subjective assessment in 0 - 5-point scale . The results showed that the force expiration technique and the Flutter(R ) with relaxation are the most efficient autodrainage methods determined by their coughed up sputum weight . Patients using these methods coughed up x 1.36 g and x 1.319 g sputum . Using Flutter(R ) without relaxation , patients expectorated 1.199 g sputum . PEP system turned out the least effective . Patients using the PEP system coughed up x 0.87 g sputum . In comparison , patients using postural drainage with clapping expectorated x 0.63 g sputum . We observed that the P 
    Output:
    
No significant difference was seen in quality of life , sputum weight , exercise tolerance , lung function , or oxygen saturation between the active cycle of breathing technique and autogenic drainage or between the active cycle of breathing technique and airway oscillating devices .
There was no significant difference in lung function and the number of pulmonary exacerbations between the active cycle of breathing technique alone or in conjunction with conventional chest physiotherapy .
There is insufficient evidence to support or reject the use of the active cycle of breathing technique over any other airway clearance therapy .
Five studies , with data from eight different comparators , found that the active cycle of breathing technique was comparable with other therapies in outcomes such as participant preference , quality of life , exercise tolerance , lung function , sputum weight , oxygen saturation , and number of pulmonary exacerbations .
Longer-term studies are needed to more adequately assess the effects of the active cycle of breathing technique on outcomes important for people with cystic fibrosis such as quality of life and preference