Tag Archives: lung

International recommendations for lung ultrasound

A multidisciplinary panel of 28 experts from eight countries reviewed the literature and came up with consensus guidelines in point-of-care lung ultrasound. There were some big names involved – all the big players in emergency/critical care ultrasound from around the World. Conspicuously absent were Matt and Mike from the Emergency Ultrasound Podcast, but maybe there was a maximum awesomeness limit or something.

Here are some snippets, taken out of context and without the grade of recommendation attached. Try to get hold of the original if you can, which might not be easy. I never understand it when ‘international recommendations’ are published as subscription-only articles. Either they want people to follow them or not. Oh well – here are some of their recommendations:
Pneumothorax

  • The sonographic signs of pneumothorax include the following: Presence of lung point(s); Absence of lung sliding; Absence of B-lines; Absence of lung pulse
  • The lung pulse refers to the subtle rhythmic movement of the visceral upon the parietal pleura with cardiac oscillations and is a rule-out sign for pneumothorax
  • In the supine patient, the sonographic technique consists of exploration of the least gravitationally dependent areas progressing more laterally.
  • Bedside lung ultrasound is a useful tool to differentiate between small and large pneumothorax, using detection of the lung point.

Interstitial syndrome

  • B-lines are defined as discrete laser-like vertical hyperechoic reverberation artifacts that arise from the pleural line (previously described as ‘‘comet tails’’), extend to the bottom of the screen without fading, and move synchronously with lung sliding.
  • The presence of multiple diffuse bilateral B-lines indicates interstitial syndrome. Causes of interstitial syndrome include the following conditions: Pulmonary edema of various causes; Interstitial pneumonia or pneumonitis; Diffuse parenchymal lung disease (pulmonary fibrosis)

Lung consolidation

  • The sonographic sign of lung consolidation is a subpleural echo-poor region or one with tissue-like echotexture.
  • Lung ultrasound is a clinically useful tool to rule in pneumonia; however, lung ultrasound does not rule out consolidations that do not reach the pleura.
  • In mechanically ventilated patients lung ultrasound should be considered as it is more accurate than portable chest radiography in the detection of consolidation.

Pleural effusion

  • Both of the following signs are present in almost all free effusions: A space (usually anechoic) between the parietal and visceral pleura; Respiratory movement of the lung within the effusion (‘‘sinusoid sign’’)
  • In opacities identified by chest radiography, lung ultrasound should be used because it is more accurate than chest radiography in distinguishing between effusion and consolidation.
  • Visualization of internal echoes, either of mobile particles or septa, is highly suggestive of exudate or hemothorax


BACKGROUND: The purpose of this study is to provide evidence-based and expert consensus recommendations for lung ultrasound with focus on emergency and critical care settings.

METHODS: A multidisciplinary panel of 28 experts from eight countries was involved. Literature was reviewed from January 1966 to June 2011. Consensus members searched multiple databases including Pubmed, Medline, OVID, Embase, and others. The process used to develop these evidence-based recommendations involved two phases: determining the level of quality of evidence and developing the recommendation. The quality of evidence is assessed by the grading of recommendation, assessment, development, and evaluation (GRADE) method. However, the GRADE system does not enforce a specific method on how the panel should reach decisions during the consensus process. Our methodology committee decided to utilize the RAND appropriateness method for panel judgment and decisions/consensus.

RESULTS: Seventy-three proposed statements were examined and discussed in three conferences held in Bologna, Pisa, and Rome. Each conference included two rounds of face-to-face modified Delphi technique. Anonymous panel voting followed each round. The panel did not reach an agreement and therefore did not adopt any recommendations for six statements. Weak/conditional recommendations were made for 2 statements, and strong recommendations were made for the remaining 65 statements. The statements were then recategorized and grouped to their current format. Internal and external peer-review processes took place before submission of the recommendations. Updates will occur at least every 4 years or whenever significant major changes in evidence appear.

CONCLUSIONS: This document reflects the overall results of the first consensus conference on “point-of-care” lung ultrasound. Statements were discussed and elaborated by experts who published the vast majority of papers on clinical use of lung ultrasound in the last 20 years. Recommendations were produced to guide implementation, development, and standardization of lung ultrasound in all relevant settings.

International evidence-based recommendations for point-of-care lung ultrasound
Intensive Care Med. 2012 Apr;38(4):577-91

Ultrasound for pneumonia

Lung ultrasound done by a single keen individual had better test characteristics than CXR in diagnosing pneumonia as defined by discharge diagnosis.
The lung ultrasound was considered to be positive for pneumonia if it showed consolidation (including air bronchograms) or a focal interstitial syndrome (localised increased density of ‘B’ lines)


Objective The aim of this study was to evaluate the diagnostic accuracy of bedside lung ultrasound and chest radiography (CXR) in patients with suspected pneumonia compared with CT scan and final diagnosis at discharge.

Design A prospective clinical study.

Methods Lung ultrasound and CXR were performed in sequence in adult patients admitted to the emergency department (ED) for suspected pneumonia. A chest CT scan was performed during hospital stay when clinically indicated.

Results 120 patients entered the study. A discharge diagnosis of pneumonia was confirmed in 81 (67.5%). The first CXR was positive in 54/81 patients (sensitivity 67%; 95% CI 56.4% to 76.9%) and negative in 33/39 (specificity 85%; 95% CI 73.3% to 95.9%), whereas lung ultrasound was positive in 80/81 (sensitivity 98%; 95% CI 93.3% to 99.9%) and negative in 37/39 (specificity 95%; 95% CI 82.7% to 99.4%). A CT scan was performed in 30 patients (26 of which were positive for pneumonia); in this subgroup the first CXR was diagnostic for pneumonia in 18/26 cases (sensitivity 69%), whereas ultrasound was positive in 25/26 (sensitivity 96%). The feasibility of ultrasound was 100% and the examination was always performed in less than 5 min.

Conclusions Bedside chest ultrasound is a reliable tool for the diagnosis of pneumonia in the ED, probably being superior to CXR in this setting. It is likely that its wider use will allow a faster diagnosis, conducive to a more appropriate and timely therapy.

Lung ultrasound is an accurate diagnostic tool for the diagnosis of pneumonia in the emergency department
Emerg Med J. 2012 Jan;29(1):19-23

B lines be gone!

Vicki Noble’s Emergency Ultrasound team describe the resolution of Songraphic B lines on the lung ultrasound of a patient with end stage renal disease who presented with dyspnoea due to pumonary oedema which was treated with CPAP.
B-lines are hyperechoic vertical lines that originate at and slide with the pleura and extend radially to the edge of the screen without fading. Isolated B-lines may be seen in normal lungs, but diffuse B-lines in multiple zones indicate interstitial thickening, most commonly seen in congestive heart failure (CHF).

Image from cardiovascularultrasound.com

This case is interesting because it describes real-time resolution of B-lines during therapy in the ED demonstrating that in CHF, B-lines reflect acute rather than chronic changes within lung parenchyma.
Real-time resolution of sonographic B-lines in a patient with pulmonary edema on continuous positive airway pressure
Am J Emerg Med. 2010 May;28(4):541.e5-8