Rationale Of A Modified Combined Use Of Inspiratory And Expiratory Pressure Threshold Training Program In Patients With Stable Chronic Obstructive Pulmonary Disease

[Background]Pulmonary rehabilitation is an integral part of clinical management of stable COPD patients,in which respiratory muscle training plays an important role.Inspiratory muscle training has been proved to increase inspiratory muscle capacity,relieve dyspnea and improve quality of life.However,the effect of the inspiratory plus expiratory training remains controversial.The adoption of threshold respiratory muscle training machine can accurately adjust the work load according to the function of respiratory muscle.At present,it has been widely applied.For the combined training of respiratory muscle at home and abroad,inspiratory and expiratory muscle training are separately adopted.The domestic hydrolock threshold respiratory muscle training machine can conduct the combined training programme for inspiratory and respiratory muscle within the same respiratory cycle,but it also has defects including large device volume and small scope of adjustable pressure load,etc.On the basis of sustainable training,this research aims to design and create a new concurrent inspiratory muscle and expiratory muscle training machine which is characterized by small volume,easy convenience and greater adjustable threshold.[Objective]This research aimed to design and create a new threshold training machine which can conduct constant inspiratory and respiratory muscle training alternately,and find out whether the combined training,compared with inspiratory muscle training,can bring about extra benefit on COPD patients.[Methods]According to the inclusion and exclusion standard,95 COPD patients were included from the outpatient clinic of Zhujiang Hospital of Southern Medical University.According to the random principle,COPD patients were assigned into four groups randomly,including the control group,inspiratory muscle training group?IMT?,concurrent inspiratory and expiratory muscle training?CRMT?,separated inspiratory and expiratory muscle training respectively?SRMT?.The control group was not involved in any respiratory muscle exercise,while different types of respiratory muscle training were conducted on IMT group,CRMT group and SRMT group for 8 weeks.After the end of respiratory muscle training,the effects were assessed by measuring changes on massive inspiratory pressure?MIP?,massive expiratory pressure?MEP?,modified MRC dyspnea scale?mMRC?,6 min walking distance?6MWD?,St.George's Respiratory Questionnaire?SGRQ?,COPD assessment test?CAT?,Hospital depression and anxiety scale?HAD?.Comparison was made on the rehabilitation effect of modified threshold training machine,traditional separated combined training and simple inspiratory muscle training.[Result]A new and modified threshold inspiratory and expiratory muscle training machine has been created to conduct the inspiratory muscle training and respiratory muscle training alternately in one respiratory cycle.The drop-out rate of IMT group was 8.70%,CRMT group 12.5%,and SRMT group 18.52%.The measures of pulmonary function?FVC,FEV1,FEV1%?and 6MWD of IMT group,CRMT group,and SRMT group were of no significant statistical difference?P>0.05?compared with the control group.The MIP of IMT group,CRMT group and SRMT group were improved by 9.791±6.870cmH₂O,9.938±6.987cmH₂O and 8.073±6.692cmH₂O?all P<0.05?respectively compared with that before training.The range of improvement of three groups had no significant difference?P>0.05?,but was markedly higher than the control group?P<0.05?.The MEP of IMT,CRMT and SRMT groups were improved by 4.276±4.067 cmH₂O,9.243±8.404 cmH₂O,and 7.096±7.954 cmH₂O respectively?all P<0.05?.Except for IMT group,the improvement range of MEP of CRMT group and SRMT group were significantly higher than that of the control group?P=0.008 and P=0.036?,but there was no significant statistical difference between the two groups?P>0.05?.The mMRC score of IMT group,CRMT group and SRMT group after training were improved by 0.3 81 ±0.498,0.286±0.463 and 0.273±0.456 respectively?P=0.002,P=0.010 ? P=0.011?.There was no significant statistical difference among the three groups?P>0.05?.The SGRQ score of IMT group,CRMT group and SRMT group after training were decreased by 3.191±1.778,4.000±2.074,and 2.636±2.752 respectively?all P<0.05?.The range of improvement was significantly higher than that of the control group?all P<0.05?,but there was no significant statistical difference among the three groups?P>0.05?.The CAT score of IMT group,CRMT group and SRMT group after training decreased by 2.238±2.700?2.714±2.306?.818±1.622 622?all P<0.05?,but there was no significant statistical difference among the three groups?P>0.05?.There were no significant changes in BODE score and HAD score between four groups?P>0.05?.The improvement range of MIP of patients with low inspiratory muscle strength in IMT group was better than that of patients with normal inspiratory muscle strength?P<0.05?;and the improvement range of MIP and MEP of patients with low inspiratory muscle strength in SRMT group were better than that of patients with normal inspiratory muscle strength?P<0.05?.There were no significant differences in static pulmonary function,exercise capacity,dyspnea scale,quality of life,depression and anxiety scale,and nutritional status between subjects with and without respiratory muscle weakness.[Conclusion]The application of this new and improved inspiratory and respiratory muscle combined training can significantly improve MIP,MEP,mMRC,SGRQ,and CAT score.Although there is no significant difference compared with the rehabilitation efficacy of SRMT,the improved machine with function of combined training is characterized by structural integrity,convenient carrying and high patient compliance.Both ways of combined training are of no significant difference in the improvement of MIP,mMRC score,SGRQ score,and CAT score in comparison to IMT,but are superior to IMT in terms of MEP improvement.In terms of lung function and 6MWD improvement,the result of lung function,6MWD,BODE index and HAD score are not significant among all groups.After respiratory muscle exercise,to compare patients with normal inspiratory muscle strength of IMT group,CRMT group and SRMT group and the patients with normal inspiratory muscle strength,the following results can be seen:MIP of IMT group improved more significantly;MIP and MEP of SRMT group improved more significantly,and the other indexes of the two groups had no obvious improvement;there was no significant difference in the improvement of the indexes of CRMT group.For the improvement of following design,data collection and management device will be installed on threshold training machine in an attempt to record the patient's training time,frequency,and intensity;monitor the patient's compliance and service condition;and accurately evaluate the rehabilitation efficacy of respiratory muscle training.