17-thoracic Ultrasound Flashcards
“Recall aspects of the ultrasound demonstration of phrenic nerve
Get patient to sniff(forced inspiration)
If normal will move down, if nerve is paralysed diaphragm will move up
“Explain the importance of probe selection
Cured array transducer: gives high depth of view+ low resolution
Linear probe: limited depth of view, high resolution
What is the gliding pleura sign
Visceral and parietal pleura is visible on US - echogenic line
This slides during breathing
What other signs may be visible on a normal lung
A’ lines run parallel to the lung edge, apparently within the lung but are artefacts
Comet tail’or B line artefacts perpendicular to lung edge = interlobular septa
What is M mode ultrasound
One dimensional display of motion (M) of echo-producing interfaces displayed against time (T) along the second axis
Gives a sea shore design in a normal lung
Which plane is most useful for thoracic ultrasound
Paracoronal or parasaggital plane
What can ultrasounds be used for
Detect pleural effusion and guide drainage
•Differentiate sub-pulmonary from sub-phrenic fluid
•Assess tumour invasion of chest wall and pleura
•Guide pleural and lung biopsy
•Identification of pneumothorax
•Assessment of respiratory muscle function
Why is ultrasound better at detecting pleural effusions that x rays
300ml of fluid is required in an x Ray, but less with US
Name some accessory respiratory muscles
SCM (sternocleidomastoid), scalenes, serratus, pectorals
Which muscles are involved in inspiration
Diaphragm contracts, moves down
•Scalenes and SCM contract and elevate ribs and move sternum anteriorly
•External intercostals (and interchondral portions of internal intercostals contract, elevate ribs
Which muscles are involved in expiration
Diaphragm relaxes, moves up
•Scalenes and SCM relax, ribs move down and sternum drops posteriorly
•External intercostals contract (aided by abdominal muscles), ribs move down
