Diaphragm Dysfunction and Rehabilitation Strategy in Patients With Chronic Obstructive Pulmonary Disease

Exercise Attenuate Diaphragm Atrophy in COPD Mice via Inhibiting the RhoA/ROCK Signaling

Background

Exercise is an indispensable component of pulmonary rehabilitation with strong anti-inflammatory effects. However, the mechanisms by which exercise prevents diaphragmatic atrophy in COPD (chronic obstructive pulmonary disease) remain unclear.

Methods

Forty male C57BL/6 mice were assigned to the control (n=16) and smoke (n=24) groups. Mice in the smoke group were exposed to the cigarette smoke (CS) for six months. They were then divided into model and exercise training groups for 2 months. Histological changes were observed in lung and diaphragms. Subsequently, agonist U46639 and antagonist Y27632 of RhoA/ROCK were subjected to mechanical stretching in LPS-treated C2C12 myoblasts. The expression levels of Atrogin-1, MuRF-1, MyoD, Myf5, IL-1β, TNF-α, and RhoA/ROCK were determined by Western blotting.

Results

Diaphragmatic atrophy and increased RhoA/ROCK expression were observed in COPD mice. Exercise training attenuated diaphragmatic atrophy, decreased the expression of MuRF-1, and increased MyoD expression in COPD diaphragms. Exercise also affects the upregulation of RhoA/ROCK and inflammation-related proteins. In in vitro experiments with C2C12 myoblasts, LPS remarkably increased the level of inflammation and protein degradation, whereas Y27632 or combined with mechanical stretching prevented this phenomenon considerably.

Conclusion

RhoA/ROCK plays an important role in the prevention of diaphragmatic atrophy in COPD.

Diaphragmatic dysfunction is associated with postoperative pulmonary complications in the aged patients underwent radical resection of esophageal cancer: a prospective observational study

Background

Diaphragmatic dysfunction escalates the susceptibility to postoperative pulmonary complications (PPCs). Currently, no study reports the occurrence of diaphragmatic dysfunction correlated with PPCs following radical resection of esophageal cancer in aged patients. We aimed to diagnose diaphragmatic dysfunction via ultrasonography and analyze diaphragmatic dysfunction's relation with PPCs after radical resection of esophageal cancer surgery in aged patients.

Methods

This prospective observational study comprised 86 aged patients undergoing radical resection of esophageal cancer. Patient characteristics data and intraoperative details were collected. Ultrasonography was performed before (preoperative) and after (first, third, and fifth day postoperatively) surgery. Outcome measures included PPCs within seven days postoperative, occurrence of diaphragmatic dysfunction, and short-term prognosis.

Results

After excluding 14 patients, we finally analyzed clinical data from 72 patients. The prevalence of PPCs was higher in the patients with diaphragmatic dysfunction than those without (19 of 23, 83% vs. 21 of 49, 43%, P=0.004). Postoperative diaphragmatic dysfunction was positively correlated with PPCs in patients who underwent elective radical esophageal cancer surgery (r=0.37, P=0.001). Persistent diaphragmatic dysfunction, furthermore, was positively correlated with the development of multiple PPCs (r=0.43, P<0.001). The logistic regression analysis revealed that age, total open procedure, and postoperative diaphragmatic dysfunction were identified as significant risk factors for PPCs, while total open procedure was an independent risk factor for diaphragmatic dysfunction.

Conclusions

Postoperative diaphragmatic dysfunction positively correlates with developing PPCs. Continuous monitoring of postoperative diaphragmatic function can screen high-risk patients with PPCs, which has specific clinical significance. Age, total open procedure, and diaphragmatic dysfunction are identified as risk factors for developing PPCs, while total open procedure specifically increases the risk for postoperative diaphragmatic dysfunction.

Ultrasound assessment of diaphragmatic dysfunction in non-critically ill patients: relevant indicators and update

Diaphragm dysfunction (DD) can be classified as mild, resulting in diaphragmatic weakness, or severe, resulting in diaphragmatic paralysis. Various factors such as prolonged mechanical ventilation, surgical trauma, and inflammation can cause diaphragmatic injury, leading to negative outcomes for patients, including extended bed rest and increased risk of pulmonary complications. Therefore, it is crucial to protect and monitor diaphragmatic function. Impaired diaphragmatic function directly impacts ventilation, as the diaphragm is the primary muscle involved in inhalation. Even unilateral DD can cause ventilation abnormalities, which in turn lead to impaired gas exchange, this makes weaning from mechanical ventilation challenging and contributes to a higher incidence of ventilator-induced diaphragm dysfunction and prolonged ICU stays. However, there is insufficient research on DD in non-ICU patients, and DD can occur in all phases of the perioperative period. Furthermore, the current literature lacks standardized ultrasound indicators and diagnostic criteria for assessing diaphragmatic dysfunction. As a result, the full potential of diaphragmatic ultrasound parameters in quickly and accurately assessing diaphragmatic function and guiding diagnostic and therapeutic decisions has not been realized.

Definition, diagnosis, and treatment of respiratory sarcopenia

PURPOSE OF REVIEW

Skeletal muscle weakness and wasting also occurs in the respiratory muscles, called respiratory sarcopenia. Respiratory sarcopenia may lead to worse clinical indicators and outcomes. We present a novel definition and diagnostic criteria for respiratory sarcopenia, summarize recent reports on the association between respiratory sarcopenia, physical and nutritional status, and clinical outcomes, and provide suggestions for the prevention and treatment of respiratory sarcopenia.

RECENT FINDINGS

Recently, a novel definition and diagnostic criteria for respiratory sarcopenia have been prepared. Respiratory sarcopenia is defined as a condition in which there is both low respiratory muscle strength and low respiratory muscle mass. Respiratory muscle strength, respiratory muscle mass, and appendicular skeletal muscle mass are used to diagnose respiratory sarcopenia. Currently, it is challenging to definitively diagnose respiratory sarcopenia due to the difficulty in accurately determining low respiratory muscle mass. Decreased respiratory muscle strength and respiratory muscle mass are associated with lower physical and nutritional status and poorer clinical outcomes. Exercise interventions, especially respiratory muscle training, nutritional interventions, and their combinations may effectively treat respiratory sarcopenia. Preventive interventions for respiratory sarcopenia are unclear.

SUMMARY

The novel definition and diagnostic criteria will contribute to promoting the assessment and intervention of respiratory sarcopenia.

Lung transcriptomics reveals the underlying mechanism by which aerobic training enhances pulmonary function in chronic obstructive pulmonary disease

BACKGROUND

Aerobic training is the primary method of rehabilitation for improving respiratory function in patients with chronic obstructive pulmonary disease (COPD) in remission. However, the mechanism underlying this improvement is not yet fully understood. The use of transcriptomics in rehabilitation medicine offers a promising strategy for uncovering the ways in which exercise training improves respiratory dysfunction in COPD patients. In this study, lung tissue was analyzed using transcriptomics to investigate the relationship between exercise and lung changes.

METHODS

Mice were exposed to cigarette smoke for 24 weeks, followed by nine weeks of moderate-intensity treadmill exercise, with a control group for comparison. Pulmonary function and structure were assessed at the end of the intervention and RNA sequencing was performed on the lung tissue.

RESULTS

Exercise training was found to improve airway resistance and lung ventilation indices in individuals exposed to cigarette smoke. However, the effect of this treatment on damaged alveoli was weak. The pair-to-pair comparison revealed numerous differentially expressed genes, that were closely linked to inflammation and metabolism.

CONCLUSIONS

Further research is necessary to confirm the cause-and-effect relationship between the identified biomarkers and the improvement in pulmonary function, as this was not examined in the present study.

Sniff and reverse-sniff nasal respiratory pressures after exacerbation of chronic obstructive pulmonary disease: A single-center prospective study

BACKGROUND

and objective: This study examined the validity of sniff nasal inspiratory (SNIP) and reverse-sniff nasal expiratory pressures (RSNEP) for estimating respiratory muscle strength and for predicting poor life expectancy following exacerbation in patients with chronic obstructive pulmonary disease (COPD).

METHODS

This prospective study included patients who were admitted for COPD exacerbation and underwent rehabilitation. At hospital discharge, SNIP, RSNEP, and maximum mouth inspiratory (MIP) and expiratory pressures (MEP) were measured, and the body mass index, degree of airflow obstruction, dyspnea, and exercise capacity (BODE) index was calculated by evaluating body mass index, forced expiratory volume in 1 s (FEV1), the Modified Medical Research Council Dyspnea Scale, and 6-min walk distance.

RESULTS

Data from 43 patients (mean age 76.8 years, FEV1 42.8 % predicted) were analyzed. SNIP and RSNEP were moderately correlated with MIP and MEP, respectively. Bland-Altman plot means of SNIP (48.3 ± 17.5) and RSNEP (44.7 ± 23.8 cmH2O) were lower than those of MIP (54.8 ± 19.9) and MEP (76.4 ± 31.2 cmH2O), respectively, and the SNIP-MIP and RSNEP-MEP 95 % limits of agreement were wide. Logistic regression showed that SNIP and RSNEP were significantly associated with BODE score ≥7 (poor life expectancy), and predictive accuracy was 81.4 % when combining SNIP ≤49 and RSNEP ≤42 cmH2O.

CONCLUSION

After exacerbation in patients with COPD, SNIP and RSNEP are useful indicators that complement MIP and MEP. Furthermore, a combined SNIP and RSNEP test may be beneficial in predicting poor life expectancy.

The Importance of the Diaphragm in Neuromotor Function in the Patient with Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a constant and chronic narrowing of the respiratory airways, with numerous associated symptoms, not always related to the pathological adaptation of the lungs. Statistical projections show that COPD could become the third leading cause of death globally by 2030, with a significant increase in deaths by 2060. Skeletal muscle dysfunction, including the diaphragm, is one of the causes linked to the increase in mortality and hospitalization. Little emphasis is given by the scientific literature to the importance of the diaphragm towards functional neuromotor pathological expressions. The article reviews the adaptation of the skeletal muscles, with greater attention to the adaptations of the diaphragm, thereby highlighting the non-physiological variations that the main respiratory muscle undergoes and the neuromotor impairment found in COPD. The text could be an important reflection from a clinical and rehabilitation point of view, to direct greater attention to the function and adaptation of the diaphragm muscle.

Effects of Ipratropium Bromide Combined with Traditional Chinese Medicine Intervention on the Pulmonary Function and Psychological Status of Patients with Chronic Obstructive Pulmonary Disease

Recently, most scholars have advocated multidisciplinary comprehensive intervention measures for chronic obstructive pulmonary disease (COPD) to improve lung function, relieve symptoms of dyspnea, and improve quality of life. Traditional Chinese medicine (TCM) has rich experience in the treatment of various respiratory system diseases and the rehabilitation of their syndrome differentiation. In this study, total 68 patients with COPD from November 2019 to November 2021 in the hospitals were divided into the control group, ipratropium bromide (IB)-treated group, and IB + TCM-treated group for clinical efficacy observation and to explore the effect of IB combined with TCM on the pulmonary function and psychological status of COPD patients. Patients in the control group were subjected to routine oxygen inhalation, cough and expectorant, and antiviral treatments, while the patients in the IB-treated group were treated with IB and those received in the control group. Patients in the IB + TCM-treated group were treated with IB and TCM intervention. All patients were treated for a month. The results showed that after different interventions, the levels of FEV1, FEV1% pred, FVC, and PEF (P < 0.05) were significantly increased in all the groups, while levels of TNF-α, IL-6, IL-8, and CRP in serum as well as Hamilton Anxiety Scale and Hamilton Depression scores were significantly decreased. Compared with the control group and IB-treated group, the IB + TCM-treated group presented the greatest changes on all abovementioned indicators and the lowest total incidence of adverse reactions, indicating the biggest improvement of IB + TCM on the symptoms of COPD patients. Therefore, the combination of IB and TCM intervention effectively improved the pulmonary function and psychological status of COPD patients and could be used as an important adjunct for COPD treatment.

Effects of external diaphragm pacing combined with conventional rehabilitation therapies in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND

Numerous randomized controlled trials (RCTs) have reported the benefits of external diaphragm pacing combined with conventional rehabilitation therapies (EDP-CRTs) on pulmonary function and exercise capacity in patients with chronic obstructive pulmonary disease (COPD). However, evidence-based regarding its effects remains unclear.

OBJECTIVES

This systematic review and meta-analysis aimed to evaluate the effects of EDP-CRTs versus CRTs on patients with COPD.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES AND METHODS

We performed a systematic review and meta-analysis, searching PubMed, Embase, Cochrane Central Register of Controlled Trials, Scopus, China Biology Medicine Disc, Chinese National Knowledge Infrastructure, Wan-Fang Database, and Chinese Scientific Journal Database from inception to 10 September 2023. RCTs investigating the effects of EDP-CRTs versus CRTs on COPD patients were included. The primary outcome was pulmonary function, including forced expiratory volume in 1 s (FEV1), the percentage of predicted values of FEV1 (FEV1%pred), and FEV1/forced vital capacity (FVC)%. Secondary outcomes included arterial blood gas analysis [the partial pressure of arterial oxygen (PaO2) and the partial pressure of arterial carbon dioxide (PaCO2)]; dyspnea [modified Medical Research Council Dyspnea Scale (mMRC)]; exercise capacity [6-min walking distance (6MWD)]; and quality of life [COPD assessment test (CAT)]. RevMan 5.3 software was used for meta-analysis. The quality of the included studies was assessed using the revised Cochrane Risk of Bias tool for randomized trials (RoB 2.0). The certainty of the evidence was evaluated with the Grading of Recommendations Assessment, Development, and Evaluation system.

RESULTS

In total, 13 studies/981 participants were included. The pooled results revealed significant benefits of EDP-CRTs versus CRTs on the FEV1 [standardized mean difference (SMD) = 1.07, 95% confidence interval (CI) = 0.58-1.56], FEV1%pred [weighted mean difference (WMD) = 6.67, 95% CI = 5.69-7.64], the FEV1/FVC% (SMD = 1.24, 95% CI = 0.48-2.00), PaO2 (SMD = 1.29, 95% CI = 0.74-1.84), PaCO2 (SMD = -1.88, 95% CI = -2.71 to -1.04), mMRC (WMD = -0.55, 95% CI = -0.65 to -0.45), 6MWD (SMD = 1.63, 95% CI = 0.85-2.42), and CAT (WMD = -1.75, 95% CI = -3.16 to -0.35), respectively. Planned subgroup analysis suggested that EDP-CRTs had a better effect on FEV1, FEV1/FVC%, 6MWD, and CAT in the duration of 2-4 weeks.

CONCLUSION

EDP-CRTs have better effects on pulmonary function, PaCO2, dyspnea, exercise capacity, and quality of life in COPD patients than CRTs, and the duration to achieve the most effective treatment is 2-4 weeks.

TRIAL REGISTRATION

This systematic review and meta-analysis protocol was prospectively registered with PROSPERO (No. CRD42022355964).

Effectiveness and safety of inspiratory muscle training in patients with pulmonary hypertension: A systematic review and meta-analysis

Background

Inspiratory muscle training (IMT) is a simple and well-tolerated physical therapy that increases respiratory muscle strength and relieving the degree of dyspnea and fatigue. Therefore, it may be used as a transitional modality before exercise training or as a specific physical therapy intervention for those who are diagnosed with respiratory muscle weakness. However, the current evidence on IMT in pulmonary hypertension (PH) patients is inconclusive. The purpose of this systematic review and meta-analysis was to summarize the current role of IMT in this group of patients.

Methods

PubMed, EMBASE, and Cochrane databases were searched through May 2022. Trials examining the feasibility and effectiveness of IMT in PH patients. Outcome measures included adverse events, training adherence and compliance, maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), forced vital capacity (FVC%), forced expiratory volume in 1 s (FEV1%), FEV1/FVC%, 6 min walk distance (6MWD), Peak VO2, dyspnea, and fatigue perception after the IMT training program. Only randomized controlled trials were included. The Cochrane Risk of Bias tool for controlled trials was adopted to assess study quality. Statistical heterogeneity was evaluated with the chi-square test and I 2 statistic. Mean differences and 95% confidence intervals (CIs) were estimated.

Results

We ultimately identified four studies that met the criteria. These studies comprised 80 patients with 16 males and 64 females. The mean age was 53.25. The main types of PH were group I (pulmonary arterial hypertension, 95%) and group IV (chronic thromboembolic PH, 5%). No severe adverse events were reported in the included studies. IMT had a significant effect on improving MIP (18.89 cmH2O; 95% CI: 9.43-28.35, P < 0.001) and MEP (8.06 cmH2O; 95% CI: 2.39-13.73; P = 0.005), increase in the 6MWD (30.16 m; 95% CI: 1.53-58.79; P = 0.04). No significant improvement was found in pulmonary function (P > 0.05), and uncertain effect on the quality of life (QoL) score.

Conclusion

Based on currently limited evidence, IMT is an effective physical therapy for increasing respiratory muscle function and exercise capacity, but still a lack of evidence on dyspnea and fatigue levels, pulmonary function, and QoL in PH patients. There are reasons to believe that IMT is a promising intervention in PH patients, enriching rehabilitation options and serving as a bridge before formal exercise training. It is expected that IMT will play an important role in the future clinical pathway of physical therapy for this group of patients.

Systematic review registration

[https://www.crd.york.ac.uk/PROSPERO/logout.php], identifier [CRD42022335972].