The Application of Diaphragm Ultrasound in Chronic Obstructive Pulmonary Disease: A Narrative Review

Figures & data

Figure 1. Diaphragm. A high-frequency linear array probe is utilized to identify the diaphragm located between the eighth to tenth intercostal space. The resulting image typically displays three parallel high and low echo bands, with the upper and lower layers representing the pleural and peritoneal membranes, respectively, and the diaphragm located in the middle.

Figure 2. Diaphragm excursion. The M-mode is utilized to detect diaphragm movement. And diaphragm excursion refers to the vertical distance from the baseline to the highest point at the end of both inspiration and expiration.

Table 1. Characteristics and findings of articles using diaphragmatic ultrasound in NIV.

Study/year	Population	Number of patients	NIV mode	Diaphragm ultrasound parameters	Acquisition time	Findings
Antenora F 2017 [76]	AECOPD	41	Pressure preset mode	TF	Admission before starting NIV	1. NIV failure was found to be strongly associated with DD (p < 0.001) 2. The ΔTdi% median value significantly higher in patients who were successful with NIV 3. DD correlated with longer ICU stay, prolonged MV, and tracheotomy
Marchioni A 2018 [73]	AECOPD	75	Pressure preset mode	TF	Admission before starting NIV	1. Patients with DD presented a higher risk for NIV failure than patients without DD 2. DD correlated with higher short- and long-term mortality, longer stay in the RICU, prolonged MV, and higher tracheostomy rate 3.ΔTdi < 20% showed higher accuracy in predicting NIV failure than baseline pH < 7.25, and both changes in arterial blood pH and PaCO2 did within 2 h after NIV was started 4.ΔTdi < 20% demonstrated the same accuracy as Pdi sniff in identifying DD
Cammarota G 2019 [75]	AECOPD	21	Pressure support mode	Right-sided DE Bilateral thickness Bilateral TF	Before starting NIV (T0), After 1 h (T1) of NIV. After 2 h (T2) of NIV	1. A greater DE in NIV successes compared to that observed in NIV failures at T0 (p = 0.02), T1 (p = 0.007), and T2 (p = 0 .008) 2. Left-sided expiratory thickness of NIV successes at T2 was higher than that of NIV failures at the same time point (p = 0.01) 3. The left expiratory DT of NIV successes increase at T2, whereas that of NIV failures remains unchanged over the whole study period.
Kocyigit H 2021 [77]	AECOPD	60	Continuous positive airway pressure-pressure support volume mode	TF	Admission before starting NIV	In predicting NIV failure, DD had a sensitivity of 84.6%, specificity of 91.5%, positive predictive value of 73.3%, and negative predictive value of 95.6%
Patel NB 2023 [78]	AECOPD	60	BIPAP mode	TF	Admission before starting NIV (T1) After 2 h of NIV (T2)	The DD criterion of ≤35.3 (T2) had a better diagnostic profile and higher log odds and hazard ratio than other thresholds (<20; ≤19.04) in estimating NIV failure.

NIV: noninvasive ventilation; AECOPD: acute exacerbations of Chronic Obstructive Pulmonary Disease: TF: thickening fraction: DE: diaphragm excursion: DD: diaphragmatic dysfunction: ΔTdi: diaphragm thickness change; ICU: intensive care units; RICU: respiratory intensive care units; MV: mechanical ventilation

Antenora F, Fantini R, Iattoni A, et al. Prevalence and outcomes of diaphragmatic dysfunction assessed by ultrasound technology during acute exacerbation of COPD: a pilot study. Respirology. 2017;22(2):338–344. doi: 10.1111/resp.12916.

 PubMed Web of Science ®Google Scholar

Marchioni A, Castaniere I, Tonelli R, et al. Ultrasound-assessed diaphragmatic impairment is a predictor of outcomes in patients with acute exacerbation of chronic obstructive pulmonary disease undergoing noninvasive ventilation. Crit Care. 2018;22(1):109. doi: 10.1186/s13054-018-2033-x.

 PubMed Web of Science ®Google Scholar

Cammarota G, Sguazzotti I, Zanoni M, et al. Diaphragmatic ultrasound assessment in subjects with acute hypercapnic respiratory failure admitted to the emergency department. Respir Care. 2019;64(12):1469–1477. doi: 10.4187/respcare.06803.

 PubMed Web of Science ®Google Scholar

Kocyigit H, Gunalp M, Genc S, et al. Diaphragm dysfunction detected with ultrasound to predict noninvasive mechanical ventilation failure: a prospective cohort study. Am J Emerg Med. 2021;45:202–207. doi: 10.1016/j.ajem.2020.08.014.

 PubMed Web of Science ®Google Scholar

Patel NB, Jain G, Chauhan U, et al. Evaluating diaphragmatic dysfunction and predicting non-invasive ventilation failure in acute exacerbation of chronic obstructive pulmonary disease in India. Acute Crit Care. 2023;38(2):200–208. doi: 10.4266/acc.2022.01060.

 PubMed Web of Science ®Google Scholar