Clinical values of diaphragmatic movement in patients with chronic obstructive pulmonary disease

Abstract

Background The limitation of activity due to dyspnea in chronic obstructive pulmonary disease (COPD) patients is affected by diaphragmatic dysfunction and reduced lung function. This study aimed to analyze the association between diaphragm function variables and forced expiratory volume in the first second (FEV1) and to estimate the clinical significance of diaphragm function in the correlation between COPD severity and lung function. Methods This prospective, single-center, cross-sectional observational study enrolled 60 COPD patients in a respiratory outpatient clinic. Data for baseline characteristics and the dyspnea scale were collected. Participants underwent a pulmonary function test (PFT), a 6-minute walk test (6MWT), and diaphragm function by ultrasonography. Results The right excursion at forced breathing showed the most significant correlation with FEV1 (r = 0.370, p = 0.004). The cutoff value was 6.7 cm of the right diaphragmatic excursion at forced breathing to identify the FEV1 above 50% group. In the group with a right diaphragmatic excursion at forced breathing < 6.7 cm, modified Medical Research Council (mMRC), St. George's Respiratory Questionnaire and the total distance of 6MWT showed no difference between groups with FEV1 under and above 50% (p > 0.05). In the group with ≥ 6.7 cm, mMRC and the total distance of 6MWT showed a significant difference between FEV1 under and above 50% (p = 0.014, 456.7 ± 69.7 m vs. 513.9 ± 60.3 m, p = 0.018, respectively). Conclusion The right diaphragmatic forced excursion was closely related to FEV1, and analysis according to the right diaphragmatic forced excursion-based cut-off value showed a significant difference between both groups. When the diaphragm function was maintained, there was a lot of difference in the 6MWT’s factors according to the FEV1 value. Our data suggest that diaphragmatic function should be performed when interpreting PFT.

Diaphragmatic Ultrasound in Children With Asthma Exacerbations

“…Prior adult literature has correlated diaphragmatic dysfunction, defined as TF of <17%-20%, with failure for intubated patients to wean from ventilation and failure of PPV in patients with acute COPD exacerbations. 4,[14][15][16] Although both the mild and moderate asthma groups had TF values over 20%, we found that those with moderate PRAM scores had a statistically significantly higher TF than the mild group. We postulate that the increased use of respiratory muscles seen in the moderate asthma group contributed to this increase in TF and that TF may not decrease below 20% until respiratory failure.…”

“…Prior adult literature has correlated diaphragmatic dysfunction, defined as TF of <17%–20%, with failure for intubated patients to wean from ventilation and failure of PPV in patients with acute COPD exacerbations 4,14–16 . Although both the mild and moderate asthma groups had TF values over 20%, we found that those with moderate PRAM scores had a statistically significantly higher TF than the mild group.…”

Diaphragm Ultrasound in Different Clinical Scenarios: A Review with a Focus on Older Patients

“…The correlation between diaphragm excursion and pulmonary volumes is so evident that some authors have proposed to use diaphragm ultrasound as a proxy for spirometry or as an auxiliary method to interpret spirometry findings in stable COPD patients [ 93 , 94 , 95 ]. In particular, the ratio between the forced expiratory diaphragmatic excursion in the first second and maximum expiratory diaphragmatic excursion is predictive of an obstructive spirometric pattern [ 93 ].…”

“…In particular, the ratio between the forced expiratory diaphragmatic excursion in the first second and maximum expiratory diaphragmatic excursion is predictive of an obstructive spirometric pattern [ 93 ]. Furthermore, diaphragmatic excursion of <67 mm at forced breathing is predictive of obstruction on spirometric tests, while normal values at this ultrasound test do not help to assess obstructive pattern and severity [ 94 ]. A phenotype characterized by low maximal inspiratory pressure on spirometry and reduced diaphragm excursion on forced breathing is particularly frequent in patients over 70 years old, is associated with impaired physical performance and could help identify subjects with respiratory sarcopenia [ 95 ].…”

“…From a clinical perspective, reduced diaphragm excursion assessed by ultrasound is also able to predict the performance on a 6 min walking test [ 94 ], exercise capacity and tolerance [ 96 , 97 ] and, most importantly, the number of yearly acute exacerbations [ 98 ].…”