Clinical Case 06

23 Aug

The case

An elderly male is bought to your ED from a nursing home. He has severe dementia and is unable to communicate but appeared to be in pain earlier as per staff. He has a known AAA  that has not been scanned recently and is tachycardia and hypotensive.

Your junior ED doctor has just completed their level 1 scan and finds the following when scanning the aorta.

CC 05.3

What does it show?

  • there is a hypo echoic somewhat circular structure visualised. While not measured it it is clearly >5cm. Your junior is concerned for leaking AAA

[collapse]
What does it really show...?

  • it’s bladder of course you numpty. You chastise the junior for being an idiot and get the patient catheterised before they get a CT scan showing urinary retention (Ed. that’s never happened to me honest…)

You perform the following scan

CC 05.1

transverse

CC 05.2

longitudinal

[collapse]
what does it show?

  • a AAA, probably around 4cm or so

[collapse]
Is it leaking?

  • tricky (but not impossible) to tell on ultrasound. Rupture rates for AAA depending on size are as follows
    • 1 percent rupture risk for AAA baseline diameter 40 to 49 mm
    • 1 to 11 percent rupture risk for AAA baseline diameter 50 to 59 mm
    • 10 to 22 percent rupture risk for AAA baseline diameter 60 to 69 mm
    • 30 to 33 percent rupture risk for AAA baseline diameter >70 mm (adapted from UpToDate)
  • An intra peritoneal rupture will have buckets of free fluid in abdomen. However the patient usually rapidly expires in this scenario
  • Most AAAs rupture retroperitoneally and there will be no free fluid in the abdomen
  • A hypotensive, tachycardic patient with a AAA should probably be imaged and see vascular emergently

[collapse]
Outcome

  • while you’re on the phone to CT your sheepish junior comes over to tell you that the patient has extensive cellulitis affecting his perineum and upper thighs likely precipitating the retention and causing the presentation. You pretend like you’ve just gone into a tunnel and hang up on the radiology reg…

[collapse]

Leave a Reply

Your email address will not be published. Required fields are marked *