An Application Study Of Combined Electrical Stimulation Of Diaphragm And Abdominal Muscle For Pulmonary Rehabilitation In Patients With Stable Chronic Obstructive Pulmonary Disease

Objective:The purpose of this clinical trial was to study the safety and efficacy of respiratory neuromuscular electrical stimulation in pulmonary rehabilitation of severe to extremely severe Chronic Obstructive Pulmonary Disease（COPD）at stable stage,and to evaluate weather combined diaphragmatic and abdominal electrical stimulation synchronically with breathing is superior to diaphragmatic stimulation alone.To provide a safer,and more effective means of pulmonary rehabilitation for patients with stable COPD.Methods:This study was a randomized,controlled,prospective and superiority research.From September 2018 to May 2019,outpatients with severe to extremely severe stable COPD were recruited in the Respiratory Department of the first Hospital of Hebei Medical University,who were randomly assigned to intervention group and control group.The intervention group received combined diaphragmatic and abdominal electrical stimulation synchronically with breathing,while the control group was treated with phrenic nerve stimulation alone.The stimulation frequency was 40Hz,once a day for 30 minutes,and totally for 4 weeks in both groups.The primary aim was the change of 6MWD before and after treatment with the two groups.Secondary indicators included the changes of m MRC,lung function,arterial blood-gas analysis,diaphragmatic mobility,and the incidence of adverse events.Above all,we were able to assess the effectiveness and safety of respiratory neuromuscular electrical stimulation in patients with stable COPD.Results:52 out of 53 participants completed the entire trial（Intervention group n=27,Control group n=25）,aged 64.17±6.14 years,male 88%.Before the study Baseline characteristics were similar between the two groups（P>0.05）.No device-related serious adverse events occurred during the treatment and follow-up period,but one case voluntarily withdrew from the trial.1.Primary efficacy outcomeThe intervention group was superior to the control group with improvements of 6MWD,regarding functional exercise performance.At the end of the study,the 6MWD of the intervention group and the control group were 540.44±62.04m and 487.44±51.49m,respectively.And there was significant difference between them（P<0.01）.There was a significant within-group increased in 6MWD from baseline to end-treatment in both the two groups（P<0.001）.2.Secondary outcome measuresCompared with the value of baseline,there was a significantly improvement with the m MRC scores,Sa O₂ and lung function parameters FEV₁,FVC,FEV₁%pred with-in two groups at end point of the trial（P<0.05,respectively）,meanwhile,there was no significant difference between two groups（P>0.05）with m MRC,Sa O₂,and lung function at the end of the trail.For the changes in arterial blood gas indexes and diaphragmatic mobility,there were no significant differences between-group or within-group at end-treatment（P>0.05）.Conclusions:1.The combined electrical stimulation of diaphragm and abdominal muscle synchronically with breathing is superior to simple phrenic nerve electrical stimulation in the improvement of exercise endurance.2.Combined electrical stimulation of diaphragm and abdominal muscle synchronically with breathing can be used as a safe and effective means of pulmonary rehabilitation for severe to extremely severe stable COPD patients who cannot tolerate exercise training.