Related Experiment Video
Updated: Mar 28, 2026

Diaphragmatic Ultrasound in Adults: Image Acquisition and Interpretation
Published on: January 31, 2025
[A comparative study of different bedside lung ultrasound examination for the location and signs of diaphragmatic
Xin Ding, Xiaoting Wang, Huan Chen
1Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China;
Objective:
To investigate the differences of the locations and signs of the phrenic points between the Modified Bedside Lung Ultrasound Examination (M-BLUE) and Bedside Lung Ultrasound Examination (BLUE).
Methods:
A total of 61 consecutive patients who were treated in the Department of Critical Care Medicine at Peking Union Medical College Hospital in January and February of 2015 were enrolled in this study. BLUE and M-BLUE were both performed on each patient. The differences of examination results were compared.
Results:
(1) There were 47.5% (58/122) different locations of the phrenic points and 18.0% (22/122) different echo-signs between the BLUE protocol and the M-BLUE protocol. (2) Compared with BLUE protocol, changes of locations [67.9% (19/28) vs 33.3% (11/33)] and signs [42.9% (12/28) vs 12.1% (4/33)] of the phrenic points in the M-BLUE protocol in patients with respiratory failure were significantly higher than those without pulmonary diseases. Among 5 patients with acute respiratory distress syndrome and 6 patients with chronic obstructive pulmonary disease, all presented changes in locations of the phrenic point in the M-BLUE protocol, while 3 and 4 showed changes in signs respectively. (3) Signs of the phrenic point in the M-BLUE protocol were more consistent with the result of the chest CT than those in the BLUE protocol.
Conclusion:
Compared with BLUE protocol, M-BLUE protocol seems more accurate in locating the phrenic point and more specific for the diagnosis of pulmonary disease. Compared with BLUE protocol, M-BLUE is more valuable for critical patients.
Related Concept Videos
Physical Assessment of the Respiratory Tract III: Percussion
Percussion in Respiratory Assessment
Percussion evaluates underlying tissue composition with audible and tactile vibrations,...
Respiratory System Abnormal Finding I: Inspection and Percussion
Inspection Findings
During an inspection, several findings may suggest the presence of respiratory distress or disease. Pursed-lip breathing, where exhalation is slowed by...
Respiratory System Abnormal Finding II: Palpation and Auscultation
Palpation Findings
During a respiratory assessment, palpation can reveal several vital abnormalities:
Assessment of Respiration
Subjective Assessment: Nurses interview the patient to gather information directly during the subjective assessment. It includes questions about the individual's medical history, medications, and symptoms, focusing on past respiratory conditions like...
Physical Assessment of the Respiratory Tract II: Palpation
Thoracic Palpation
Thoracic palpation detects tenderness, masses, lesions, respiratory excursions, and vocal fremitus. The nurse assesses...
Ultrasound II: Endoscopic Ultrasound and FibroScan
Endoscopic Ultrasound (EUS):

