Test yourself
Urinary retention: measure the bladder, then look upstream
4 questions. Pick an answer to see whether you are right and why. Your score appears at the end.
Question 1Which planes do you need to estimate bladder volume?
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Answer b. The ellipsoid formula needs three diameters. The transverse view gives width and depth, and the sagittal view gives the head-to-foot length.
Question 2What factor do you multiply the three bladder diameters by to estimate volume?
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Answer d. The bladder approximates an ellipsoid, and 0.52 (π/6) is the ellipsoid factor. The result is an estimate, so record it and compare with the volume drained.
Question 3A patient in retention has a large bladder and bilateral hydronephrosis. What does this suggest?
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Answer d. Back pressure from a large retained bladder dilates both collecting systems. Check renal function and monitor for diuresis after catheterisation.
Question 4A catheterised patient has a full bladder on scan with little in the bag. What do you look for?
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Answer a. A full bladder around a catheter means it is blocked or not in the bladder. Find the balloon. A balloon in the urethra needs urgent attention.
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Four or five delegates per instructor, FAMUS-accredited faculty and long, supervised time on the probe.
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