Physiological responses to Tai Chi in stable patients with COPD.
Qiu Zhi-Hui,Guo Hong-Xi,Lu Gan,Zhang Ning,He Bai-Ting,Zhou Lian,Luo Y M,Polkey M I
Respiratory physiology & neurobiology
We compared the physiological work, judged by oxygen uptake, esophageal pressure swing and diaphragm electromyography, elicited by Tai Chi compared with that elicited by constant rate treadmill walking at 60% of maximal load in eleven patients with COPD (Mean FEV1 61% predicted, FEV1/FVC 47%). Dynamic hyperinflation was assessed by inspiratory capacity and twitch quadriceps tension (TwQ) elicited by supramaximal magnetic stimulation of the femoral nerve was also measured before and after both exercises. The EMGdi and esophageal pressure at the end of exercise were similar for both treadmill exercise and Tai Chi (0.109±0.047 mV vs 0.118±0.061 mV for EMGdi and 22.3±7.1 cmH2O vs 21.9±8.1 cmH2O for esophageal pressure). Moreover the mean values of oxygen uptake during Tai Chi and treadmill exercise did not differ significantly: 11.3 ml/kg/min (51.1% of maximal oxygen uptake derived from incremental exercise) and 13.4 ml/kg/min (52.5%) respectively, p>0.05. Respiratory rate during Tai Chi was significantly lower than that during treadmill exercise. Both Tai Chi and treadmill exercise elicited a fall in IC at end exercise, indicating dynamic hyperinflation, but this was statistically significant only after treadmill exercise. TwQ decreased significantly after Tai Chi but not after treadmill. We conclude that Tai Chi constitutes a physiologically similar stimulus to treadmill exercise and may therefore be an acceptable modality for pulmonary rehabilitation which may be culturally more acceptable in some parts of the world.
[Neural respiratory drive and nocturnal hypoventilation in patients with chronic obstructive pulmonary disease].
Xu Jing,Yuan Hong,Wu Ying-xin,Xiao Si-chang,Zhang Han-jia,Luo Yuan-ming
Zhonghua yi xue za zhi
OBJECTIVE:To explore the effects of neural respiratory drive on ventilation in patients with chronic obstructive pulmonary disease (COPD) during sleep. METHODS:Diaphragm electromyogram (EMG) from a multipair esophageal electrodes and airflow derived from pneumotachography were recorded during overnight polysomnography in 13 patients with stable COPD recruited from outpatient clinic of First Affiliated Hospital of Guangzhou Medical College from May 2010 to May 2011. Changes in diaphragm EMG and ventilation during wakefulness and different sleep stages were observed. RESULTS:Diaphragm EMG decreased by 26% in non-rapid eye movement sleep (NREM) stage and 39% in rapid eye movement (REM) as compared with wakefulness. Coinciding with change in diaphragm EMG, ventilation (VE) (ml×min(-1)×kg(-1)) significantly decreased from wakefulness (156 ± 53) ml×min(-1)×kg(-1) to steady NREM stage (112 ± 35) ml×min(-1)×kg(-1) (P < 0.05) and further decreased from NREM stage to REM stage (95 ± 27) ml×min(-1)×kg(-1) (P < 0.05). Oxygen saturation also decreased significantly from 97.1% ± 1.8% in wakefulness to REM stage (94.0% ± 3.9%) (P < 0.01). CONCLUSION:Reduced neural respiratory drive contributes to nocturnal hypoventilation in COPD patients.
Correlation and compatibility between surface respiratory electromyography and transesophageal diaphragmatic electromyography measurements during treadmill exercise in stable patients with COPD.
Wu Weiliang,Guan Lili,Li Xiaoying,Lin Lin,Guo Bingpeng,Yang Yuqiong,Liang Zhenyu,Wang Fengyan,Zhou Luqian,Chen Rongchang
International journal of chronic obstructive pulmonary disease
Purpose:To evaluate the compatibility and correlation between noninvasive surface respiratory electromyography and invasive transesophageal diaphragmatic electromyography measurements as facilitating indicators of neural respiratory drive (NRD) evaluation during treadmill exercise. Patients and methods:Transesophageal diaphragmatic electromyogram activity (EMGdi,es) and surface inspiratory electromyogram (EMG) activity, including surface diaphragmatic EMG activity (EMGdi,sur), surface parasternal intercostal muscle EMG activity (EMGpara), and surface sternocleidomastoid EMG activity (EMGsc), were detected simultaneously during increasing exercise capacity in 20 stable patients with COPD. EMGdi,es, EMGdi,sur, EMGpara, and EMGsc were quantified using the root mean square (RMS) and were represented as RMSdi,es, RMSdi,sur, RMSpara, and RMSsc, respectively. Results:There was a significant association between EMGdi,es and EMGdi,sur (=0.966, <0.01), EMGpara (=0.967, <0.01), and EMGsc (=0.956, <0.01) in the COPD patients during exercise. Bland-Altman plots showed that the lowest mean bias value was between EMGdi,es and EMGpara compared with the bias values between EMGdi,es and the other two EMG parameters. In comparing the estimation of EMGdi,es, we observed the lowest bias values (-1%) and the lowest limits of agreement values (-10% to -12%). Intraclass correlation coefficient (ICC) between EMGdi,es and EMGdi,sur was 0.978 (<0.01), between EMGdi,es and EMGpara was 0.980 (<0.01), and between EMGdi,es and EMGsc was 0.868 (<0.01). Conclusion:RMSdi,sur, RMSpara, and RMSsc could provide useful physiological markers of NRD in COPD. RMSpara shows the best compatibility and correlation with transesophageal diaphragmatic electromyography during treadmill exercise in stable patients with COPD.
Respiratory electrophysiologic studies in chronic obstructive pulmonary disease.
Wang Yu,Liu Na,Zhang Zhecheng
Respiratory failure is common during acute exacerbation of chronic obstructive pulmonary disease (AE-COPD). Phrenic nerve conduction (PNC), transcranial magnetic stimulation (TMS), and cervical magnetic stimulation (CMS) are of great value in identifying the feature and site of AE-COPD.PNC, TMS, and CMS were performed in 20 AE-COPD patients with respiratory failure, and re-examined after weaning. Latencies and amplitudes of the diaphragmatic compound muscle action potential (dCMAP), motor evoked potential of the diaphragm (dMEP) evoked by TMS and CMS, and central motor conduction time (CMCT) were measured. Blood gas analysis and serum electrolyte levels were also evaluated. The results were compared with those from 20 healthy subjects.AE-COPD patients showed prolonged CMCT and latencies of dCMAP and dMEP, decreased amplitudes of dCMAP and dMEP evoked by CMS, while CMCT and the latency of dMEP evoked by TMS were shortened after weaning. Significant correlation was identified between arterial blood gas analysis, serum electrolyte levels, disease duration, the duration of mechanical ventilation and the electrophysiological findings in AE-COPD patients prior to weaning.The central and peripheral respiratory pathway is involved in AE-COPD. Central respiratory pathway function is improved after weaning in AE-COPD patients with respiratory failure.
Diaphragmatic motor cortex hyperexcitability in patients with chronic obstructive pulmonary disease.
Elnemr Rehab,Sweed Rania Ahmad,Shafiek Hanaa
BACKGROUND AND OBJECTIVES:Respiratory muscles dysfunction has been reported in COPD. Transcranial magnetic stimulation (TMS) has been used for assessing the respiratory corticospinal pathways particularly of diaphragm. We aimed to study the cortico-diaphragmatic motor system changes in COPD using TMS and to correlate the findings with the pulmonary function. METHODS:A case control study recruited 30 stable COPD from the out-patient respiratory clinic of Main Alexandria University hospital- Egypt and 17 healthy control subjects who were subjected to spirometry. Cortical conduction of the diaphragm was performed by TMS to all participants followed by cervical magnetic stimulation of the phrenic nerve roots. Diaphragmatic resting motor threshold (DRMT), cortical motor evoked potential latency (CMEPL), CMEP amplitude (CMEPA), peripheral motor evoked potential latency (PMEPL), PMEP amplitude (PMEPA) and central motor conduction time (CMCT) were measured. RESULTS:66.7% of COPD patients had severe and very severe COPD with median age of 59 (55-63) years. There was statistically significant bilateral decrease in DRMT, CMEPA and PMEPA in COPD group versus healthy subjects and significant increase in CMEPL and PMEPL (p <0.01). Left CMCT was significantly prolonged in COPD group versus healthy subjects (p <0.0001) but not right CMCT. Further, there was significant increase in CMEPL and CMCT of left versus right diaphragm in COPD group (p = 0.003 and 0.001 respectively) that inversely correlated with FEV1% and FVC% predicted. Right and left DRMT were insignificantly different in COPD group (p >0.05) but positively correlated with FEV1/FVC, FEV1% and FVC% predicted. CONCLUSION:Central cortico-diaphragmatic motor system is affected in COPD patients with heterogeneity of both sides that is correlated with pulmonary function. SIGNIFICANCE:Coticospinal pathway affection could be a factor for development of diaphragmatic dysfunction in COPD patients accordingly its evaluation could help in personalization of COPD management especially pulmonary rehabilitation programs.
Inhaled Beta Agonist Bronchodilator Does Not Affect Trans-diaphragmatic Pressure Gradient but Decreases Lower Esophageal Sphincter Retention Pressure in Patients with Chronic Obstructive Pulmonary Disease (COPD) and Gastroesophageal Reflux Disease (GERD).
Del Grande Leonardo M,Herbella Fernando A M,Bigatao Amilcar M,Jardim Jose R,Patti Marco G
Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract
BACKGROUND:Chronic obstructive pulmonary disease (COPD) patients have a high incidence of gastroesophageal reflux disease (GERD) whose pathophysiology seems to be linked to an increased trans-diaphragmatic pressure gradient and not to a defective esophagogastric barrier. Inhaled beta agonist bronchodilators are a common therapy used by patients with COPD. This drug knowingly not only leads to a decrease in the lower esophageal sphincter (LES) resting pressure, favoring GERD, but also may improve ventilatory parameters, therefore preventing GERD. AIMS:This study aims to evaluate the effect of inhaled beta agonist bronchodilators on the trans-diaphragmatic pressure gradient and the esophagogastric barrier. METHODS:We studied 21 patients (mean age 67 years, 57 % males) with COPD and GERD. All patients underwent high-resolution manometry and esophageal pH monitoring. Abdominal and thoracic pressure, trans-diaphragmatic pressure gradient (abdominal-thoracic pressure), and the LES retention pressure (LES basal pressure-transdiaphragmatic gradient) were measured before and 5 min after inhaling beta agonist bronchodilators. RESULTS:The administration of inhaled beta agonist bronchodilators leads to the following: (a) a simultaneous increase in abdominal and thoracic pressure not affecting the trans-diaphragmatic pressure gradient and (b) a decrease in the LES resting pressure with a reduction of the LES retention pressure. CONCLUSION:In conclusion, inhaled beta agonist bronchodilators not only increase the thoracic pressure but also lead to an increased abdominal pressure favoring GERD by affecting the esophagogastric barrier.
Study of the diaphragm in chronic obstructive pulmonary disease using ultrasonography.
Jain Sanket,Nair Girija,Nuchin Abhishek,Uppe Abhay
Lung India : official organ of Indian Chest Society
Aims and Objectives:The study aims to compare the changes in the diaphragm in chronic obstructive pulmonary disease (COPD) patients in Indian population with the help of ultrasound-guided examination. (1) Changes in thickness of the diaphragm during respiration( to rule out diaphragm muscle atrophy). (2) The movement of the diaphragm(correlates with strength and endurance of diaphragm fibres) . (3) Zone of apposition(gives mechanical advantage to diaphragm). (4) Correlation with COPD severity by global initiative for chronic obstructive lung disease (GOLD) staging. Subjects and Methods:Forty-eight COPD patients attending OPD of DY Patil Hospital were recruited in the study and twenty age-matched controls were taken. Detailed history, pulmonary function test examination, and diaphragm study under ultrasonography was done. Results:The movement of diaphragm was reduced in mild to moderate COPD (A and B) but increased in COPD with Grade C. Movement of diaphragm was significantly more in cases with COPD Grade B (2.329 cm) and C (2.269 cm) as compared to controls (1.891 cm). Mean diaphragmatic thickness during inspiration and expiration, change in thickness, and zone of apposition were significantly higher in patients with COPD score Grade C as compared to Grade A or B. Zone of apposition was significantly decreased in Grade A (3.257 cm) and B (3.429 cm) compared to control (4.268 cm), while it was significantly increased in cases with Grade C (5.138 cm). Conclusion:The diaphragm is the main muscle of respiration, and study of diaphragm is very important in COPD. The diaphragm thickness, movement, and zone of apposition were significantly reduced in mild to moderate COPD but increased in severe COPD. This cannot be explained by physiotherapy or collagen accumulation. Hence, diaphragm muscle biopsy and electromyogram study in COPD patients will be required to get a better understanding of this muscle in COPD.
Neural Respiratory Drive Measured Using Surface Electromyography of Diaphragm as a Physiological Biomarker to Predict Hospitalization of Acute Exacerbation of Chronic Obstructive Pulmonary Disease Patients.
Zhang Dan-Dan,Lu Gan,Zhu Xuan-Feng,Zhang Ling-Ling,Gao Jia,Shi Li-Cheng,Gu Jian-Hua,Liu Jian-Nan
Chinese medical journal
Background:Neural respiratory drive (NRD) using diaphragm electromyography through an invasive transesophageal multi-electrode catheter can be used as a feasible clinical physiological parameter in patients with chronic obstructive pulmonary disease (COPD) to provide useful information on the treatment response. However, it remains unknown whether the surface diaphragm electromyogram (EMGdi) could be used to identify the deterioration of clinical symptoms and to predict the necessity of hospitalization in acute exacerbation of COPD (AECOPD) patients. Methods:COPD patients visiting the outpatient department due to acute exacerbation were enrolled in this study. All patients who were subjected to EMGdi and classical parameters such as spirometry parameters, arterial blood gas analysis, COPD assessment test (CAT) score, and the modified early warning score (MEWS) in outpatient department, would be treated effectively in the outpatient or inpatient settings according to the Global Initiative for Chronic Obstructive Lung Disease guideline. When the acute exacerbation of the patients was managed, all the examination above would be repeated. Results:We compared the relationships of admission-to-discharge changes (Δ) in the normalized value of the EMGdi, including the change of the percentage of maximal EMGdi (ΔEMGdi%max) and the change of the ratio of minute ventilation to the percentage of maximal EMGdi (ΔVE/EMGdi%max) with the changes of classical parameters. There was a significant positive association between ΔEMGdi%max and ΔCAT, ΔPaCO, and ΔpH. The change (Δ) of EMGdi%max was negatively correlated with ΔPaO/FiOin the course of the treatment of AECOPD. Compared with the classical parameters including forced expiratory volume in 1 s, MEWS, PaO/FiO, the EMGdi%max (odds ratio 1.143, 95% confidence interval 1.004-1.300) has a higher sensitivity when detecting the early exacerbation and enables to predict the admission of hospital in the whole cohort. Conclusions:The changes of surface EMGdi parameters had a direct correlation with classical measures in the whole cohort of AECOPD. The measurement of NRD by surface EMGdi represents a practical physiological biomarker, which may be helpful in detecting patients who should be hospitalized timely.