Page 2139 - Cote clinical veterinary advisor dogs and cats 4th

1066 Blood Pressure Measurement

• The crystal is placed against the patient’s Oscillometric method:
Preparation: Important skin concave side down; the flat aspect of • Restrain the animal in a comfortable position,
Checkpoints
VetBooks.ir • Be sure the animal has acclimated to • Turn volume knob to low setting, and turn tization. The position of the animal depends
and allow time and reassurance for acclima-
the crystal faces outward.
on animal’s temperament and mobility and
the clinic’s environment and is calm and
amplifier on. Verify correct position of crystal
comfortable in lateral or sternal recumbency
in the artery beneath the crystal. Adjust
or sitting. BP values may be obtained in by listening for clear pulsatile sounds of flow on the planned position of the cuff.
○ Cuff on forelimb at level of radius:
standing animals only if a tail cuff is used. the crystal position or angle as necessary to sternal or lateral recumbency or sitting
Owner presence and assurance may help calm improve signal strength if sounds are soft, position
the animal. distant, or muffled. ○ Cuff on distal hindlimb at level of meta-
• Be sure the cuff size used is appropriate and • Gently position limb so cuff is at the level tarsus (median artery): lateral recumbency
noted in the record for future reference. The of the right atrium during readings. preferred; sternal recumbency may be
width of the cuff should be ≈40% of the ○ Sternum level if animal is in lateral used if limb is in gentle extension during
circumference of the limb or tail at the cuff position measurement.
site. ○ Thoracic inlet level if animal is sternal or ○ Cuff on proximal tail head: sternal or
• During measurements with either method, sitting lateral recumbency or standing if animal
the cuff should be at the level of the right • While listening to sound of pulsatile flow, is relatively immobile during readings (tail
atrium. This may involve elevating a fore- inflate the cuff using the bulb manometer head is preferred cuff site for oscillometric
limb during measurement if the animal is to approximately 20 mm Hg greater than measurement technique in cats).
sitting. the pressure needed to cut off flow sounds. ○ Limb cuffs should not be used in standing
• BP should be measured by well-trained • Slowly deflate the cuff (1-3 mm Hg per animals.
individuals in the practice to maximize second), and note pressure at which pulsatile • Measure the circumference of the limb or
consistency. This is especially important sounds of flow recur. This pressure is recorded tail at the intended cuff site, and choose an
when Doppler methods are used. as the systolic pressure. appropriately sized cuff.
• Completely deflate the cuff, and count the • Wrap the cuff snugly around the limb, with
Possible Complications and heart rate in the approximately 30 seconds the center of the inflatable bladder of the
Common Errors to Avoid between pressure readings. A contemporary cuff positioned over the artery, and attach
• Erratic oscillometric readings may be heart rate can be recorded with each BP to the BP monitor.
obtained if an arrhythmia or very high heart reading. • Gently position limb so cuff is at the level
rate is present. • Record at least 6 measurements in succes- of the right atrium during readings (no
• Turn volume knob to low or zero before sion, allowing approximately 30 seconds to repositioning required if tail cuff is used).
turning Doppler amplifier on; then gradually 1 minute between measurements to allow ○ Sternum level if animal is in lateral
increase volume to search for the pulse after for limb reperfusion. position
contact is established between the crystal • Discard the first reading, and average the ○ Thoracic inlet level if animal is sternal or
and the patient’s skin. Failing to do this can results of the remaining readings to obtain sitting
produce extremely loud static noise that is a representative number for systolic pressure • Record at least 6 measurements in succes-
startling to the patient (if using speakers) and heart rate. High heart rate may indicate sion, allowing approximately 30 seconds to
or deafening to the operator (if using that increased levels of stress have affected 1 minute between measurements to allow
headphones). readings. If the BP is trending down with for limb reperfusion.
• For maximal accuracy in Doppler readings, successive measurements, extra measurements • Discard the first reading and any readings
be sure the audible signal is strong before may be recorded, and the last 5 values aver- with clearly spurious results, and average the
beginning cuff occlusions. aged for a representative value. results of the remaining readings to obtain a
Procedure
Doppler method:
• Restrain the animal in a comfortable position,
and allow time and reassurance for acclima-
tion. The position of the animal depends on
the animal’s temperament and mobility and
on the planned position of the cuff.
○ Cuff on forelimb at level of radius: sternal
or lateral recumbency or sitting position
○ Cuff on hindlimb proximal to hock (tibial
level) or distal hindlimb (metatarsal level):
lateral recumbency preferred; sternal
recumbency may be used if limb is in
gentle extension during measurement.
• Measure the circumference of the limb or
tail at the intended cuff site, and select an
appropriately sized cuff (see above).
• Wrap the cuff snugly around the limb, and
attach to sphygmomanometer.
• Clip or dampen hair as needed at site of
Doppler crystal application distal to the cuff BLOOD PRESSURE MEASUREMENT Doppler method is used for estimating blood pressure (BP) in a
cat. The patient is restrained in a calm, comfortable position. Cuff is applied to a distal forelimb, and limb is
(palmar or plantar arterial arch, proximal to elevated such that cuff is at level of right atrium during readings. Coupling gel is applied to Doppler crystal
the metacarpal/metatarsal pad and slightly (shown). After Doppler crystal is positioned over palmar arterial arch and a strong audible signal is obtained,
medial); apply coupling gel, and hold or bulb sphygmomanometer is used for inflating cuff and occluding arterial flow and then slowly deflated. Pressure
tape crystal in position. at which arterial flow is again audible is recorded as the systolic BP.

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