Abdominal EDE Flashcards
What is the external landmark for abdominal US (both RUQ and LUQ)?
Intersection of Posterior axillary line and xiphoid process
What is the internal landmark for abdominal US?
kidney
What are the areas of interest for abdominal US (RUQ & LUQ)?
RUQ- hepatorenal interface
LUQ- splenorenal interface and medial area caudal to the diaphragm
What are the steps to an abdominal scan?
1) Start at external landmark, move probe in post/ant plane to find brightest whitest kidney capsule
2) Move probe longitudnially to find the best view of the interface
3) Magnify the image while keeping spine visible
4) Sweep interface, including caudal tip of solid organ (liver) until kidney disappears in both directions
*LUQ only
5) Adjust using troubleshooting manoeuvres to visualize the medial aspect of the area caudal to the diaphragm (6 to 9 o’clock)
What are some techniques to avoid rib shadow when scanning the RUQ/LUQ?
1) Move in the longitudinal plane (bold moves, 2-3 rib spaces at a time)
2) Rotate probe so that it is parallel to the ribs, sending beam through intercostal space
3) Time sweeps with patient’s spontaneous respirations
4) Vary the patient’s respirations- Ask patient to take a breath in or out to move interface out of rib shadows
What are the CPOCUS steps for troubleshooting when finding the diaphragm in the LUQ?
“Ice cream cone approach”
1) Find the best view of the kidney by moving anterior/posterior
2) Move cephalad in longitudinal plane to try and capture the entire 6-9 o’clock view of the diaphragm
3) Rotate the probe through the intercostal spaces
4) While still rotated, move anteriorly and sweep posteriorly (OR move posteriorly sweep anteriorly)
5) If the above doesn’t work, move the probe back to the position achieved in step 1, then move caudally in the longitudinal plain and heel cephalad up through the spleen
Assessments of the upper quadrants must include the ____________ of both the liver and the spleen. Disappearance of the kidney is the end point of these sweeps.
Caudal tips
What are troubleshooting tips to help visualize caudal tips of solid organs?
1) Slide the probe caudally along the longitudinal plane
2) Slide probe anteriorly
3) Rotate the probe
What are pitfalls in image interpretation in the abdominal scan (7)?
1) Attempting to interpret interfaces with rib shadows
2) Mistaking perinephritic fat for free fluid
3) Mistaking clotted blood for perinephritic fat
4) Mistaking ascites for blood
5) Mistaking urine for blood
6) Mistaking intraluminal bowel fluid
7) Mistaking the stomach wall for diaphragm in LUQ
The absence of visible free fluid on FAST only rules out hemoperitoneum greater than ____ mL
250 mL
*Clinical impression is more important in the right context
Patients with ________ may have fluid sequestered away not accessible by POCUs, and are at risk for having a false negative scan.
Multiple surgeries (“Battlefield abdomen”)
Why can’t you rely on a negative FAST on a trauma patient whose presentation is delayed?
After several hours, blood becomes clotted and more echogenic, causing it to be mistaken for perinephritic fat or missed entirely
________ position can increase the sensitivity of an upper quadrant scan
Trendelenberg
The kidney defines the ________ of the scan, but the _____________ defines the location and extent of the interface.
End points, solid organ (including caudal tips)
*This is because the fluid will collect against the solid organ. To ensure free fluid isn’t missed you must see the entire solid organ, including caudal tip, but not necessarily the entire kidney.
What is required for a determinate NEGATIVE scan for the upper quadrants?
The entire interface, including solid organ, must be visualized and swept completely until the kidney disappears in both directions
AND
The medial aspect of the area caudal to diaphragm (6 to 9 o’clock) must be visualized
… With no free fluid :)
