User manual
10
Doppler Procedure
Doppler detects blood flow in arteries and veins. The radial, cranial, tibial, and
median coccygeal arteries are the most practical to monitor. Our preference is the
cranial tibial artery because the hair clipping that is required is least noticeable.
However, the other two arteries are acceptable and preferred by some. When using
the median tibial artery for cats, place a 2-4 cm wide cuff above the hock. Stress
must be minimized is to get meaningful blood pressure readings. Allow your patient
a few minutes to rest in a quiet place away from other animals before proceeding.
The presence of the owner is very helpful in relieving your patient’s stress. Take
advantage of this if possible. (NOTE: Ensure that all comparable measurements for
each animal is taken at the same location because pressure will vary with location.)
1. Assemble the Doppler unit before addressing the patient. If you believe
Doppler audio will agitate the patient, plug in the headphones and place the
headset over your ears.
2. Position the cuff proximal to the hock, proximal to the elbow, or at the base of
the tail, depending on the artery used. (NOTE: Cuff size in width should be
40% of the circumference of the limb at the site of placement. Making use of
the size gauge printed on the cuff will ensure that a cuff of the correct width
is used.)
3. Turn the unit on and verify that the volume is set in the high range and then
turn the unit back off again. (NOTE: Arterial blood flow may be difficult to
detect if the volume is set too low.)
4. Clip hair as short as possible at the palmar aspect of the foot just proximal to
the metacarpal pad. Wet the hair with alcohol and rub a small amount of
ultrasound gel into the skin in the midline area where the palmar arterial arch,
located slightly medial to the midline. You can palpate the pulse on large dogs.
(NOTE: Clipping the hair may NOT be necessary if hair is short and very fine
and is first wetted with alcohol.)