Diaphragmatic excursion correlates with exercise capacity and dynamic hyperinflation in COPD patients

Abstract

BackgroundAlthough the pathophysiological mechanisms involved in the development of dyspnoea and poor exercise tolerance in patients with chronic obstructive pulmonary disease (COPD) are complex, dynamic lung hyperinflation (DLH) plays a central role. Diaphragmatic excursions can be measured by ultrasonography (US) with high intra- and interobserver reliability. The objective of this study was to evaluate the effect of diaphragmatic excursions as assessed by US on exercise tolerance and DLH in patients with COPD.MethodsPatients with COPD (n=20) and age-matched control subjects (n=20) underwent US, which was used to determine the maximum level of diaphragmatic excursion (DEmax). Ventilation parameters, including the change in inspiratory capacity (ΔIC), were measured in the subjects during cardiopulmonary exercise testing (CPET). We examined the correlations between DEmax and the ventilation parameters.ResultsThe DEmax of patients with COPD was significantly lower than that of the controls (45.0±12.8 mm versus 64.6±6.3 mm, respectively; p<0.01). The perception of peak dyspnoea (Borg scale) was significantly negatively correlated with DEmax in patients with COPD. During CPET, oxygen uptake/weight (VO2/W) and minute ventilation (VE) were significantly positively correlated with DEmax, while VE/VO2 and VE/carbon dioxide output (VCO2) were significantly negatively correlated with DEmax in patients with COPD. DEmax was also significantly positively correlated with ΔIC, reflecting DLH, and with VO2/W, reflecting exercise capacity.ConclusionReduced mobility of the diaphragm was related to decreased exercise capacity and increased dyspnoea due to dynamic lung hyperinflation in COPD patients.

Diaphragmatic excursion is correlated with the improvement in exercise tolerance after pulmonary rehabilitation in patients with chronic obstructive pulmonary disease

“…In addition, the model using DE max had better prediction performance than that using PI max . The high predictability of DE max may be because of its strong association with DLH and dyspnoea during exercise, as reported previously [9]. DLH is involved in the development of dyspnoea, and both are important factors to determine the improvement in 6MWD in patients with COPD.…”

“…Using the liver as an acoustic window (Fig. 1A), a convex 3.5 MHz probe was used to measure the excursions of the right hemidiaphragm according to the techniques mentioned in previous studies [9,12,13]. The M-mode cursor was rotated and placed on the axis of diaphragmatic displacement on the stored image, and displacement measurements were performed.…”

“…Considering the role of DLH in the development of dyspnoea and poor exercise tolerance in patients with COPD, objective measures that reflect the degree of DLH may help in identifying good responders to PR. Previously, we reported that there was an association between increased dyspnoea due to DLH on exercise and decreased exercise capacity in patients with COPD and reduced mobility of the diaphragm, which was assessed by the maximum level of diaphragm excursion (DE max ) using ultrasonography [9]. Other research groups reported the utility of ultrasonographic assessment of diaphragmatic mobility in COPD in understanding its association with 6-min walk distance (6MWD), dyspnoea [10] and increased mortality [11].…”

Combined Use of Electrocardiography and Ultrasound to Detect Cardiac and Pulmonary Involvement after Recovery from COVID-19 Pneumonia: A Case Series

“…Although LUS diaphragmatic excursion proved to predict successful weaning in critically ill patients during the acute phase of the disease [36], to the best of our knowledge, this is the first study to evaluate DT and DE values in fully recovered patients. Considering the proven role of these echo parameters in assessing a decreased exercise capacity and increased dyspnoea in COPD patients [37], they might as well predict the outcome of patients after COVID-19 pneumonia. However, considering the contrasting evidence on the results of pulmonary function tests after SARS-CoV-2-related pneumonia [38,39], prospective and more powered studies are mandatory to define the abnormal thresholds, feasibility and diagnostic power of such echo imaging techniques in this patient population.…”

The Feasibility of Ultrasonographic Diaphragmatic Excursion in Healthy Dogs: Effect of Positioning, Diaphragmatic Location, and Body Weight of Dogs

“…Initially, DE was used to detect the respiratory problems that induced dyspnea (1). In the last few years, studies have shown that DE can be utilized in several aspects of detection and clinical assistance, i.e., the detection of phrenic-nerve-injury-induced diaphragmatic paralysis (3)(4)(5), the evaluation of chronic obstructive pulmonary disease (6)(7)(8), or chronic pulmonary disease patients (9), the assessment of respiratory function in post-thoracentesis (10), or chronic kidney disease patients with hemodialysis (11), the guided technique for ventilator use and weaning in critically ill patients (12)(13)(14), and as an intervention in the diaphragmatic pacing protocol for the appropriate stimulation of diaphragmatic muscle (15)(16)(17)(18).…”