Page 42 - Basic Monitoring in Canine and Feline Emergency Patients

(B)
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(A)

Fig. 2.8. The placement of cuffs when performing indirect blood pressure monitoring (similar location is used for both
Doppler blood pressure measurement and oscillometric blood pressure monitoring). (A) The cuff is placed between
the elbow and carpus when utilizing the forelimb’s medial palmar artery for blood pressure monitoring. (B) The cuff is
placed between the stifle and hock when utilizing the hindlimb’s dorsal pedal artery for blood pressure monitoring.

The cuff should be placed snugly on the limb and
secured with a hook and loop fastener on the cuff
(Fig. 2.8). Occasionally, white medical tape can be
used to augment the hook and loop fastener to pre-
vent the cuff from opening up during cuff inflation.
If tape is used, it should be placed loosely so as to
not alter the pressure reading of the cuff during
inflation. Prior to inflation, the cuff should be placed
tightly enough that a finger cannot be inserted
between the cuff and the patient’s limb or tail.
The fur at the intended arterial detection site is
clipped and ultrasound gel is placed on the Doppler
transducer. Ultrasound gel is critical as air between
the probe and the skin will not clearly conduct
sound (Fig. 2.9). Once the ‘whoosh’ audible signal
is noted, the transducer is held gently over the
artery. It should be noted that excessive pressure
should not be used to hold the transducer over the
site as it may affect the blood flow and generation Fig. 2.9. The clipped fur proximal to the metacarpal
of an audible signal. The sphygmomanometer is pad. Ultrasound gel is placed on the probe and the
then used to inflate the cuff until the audible sound probe is then placed against the skin and the position
is no longer heard. The cuff is inflated 20–30 mmHg adjusted until an audible ‘whoosh’ is heard (this sound
beyond the point at which the sound is no longer confirms the probe is detecting arterial blood flow).
audible and then the pressure is slowly released.
The pressure at which the ‘whoosh’ sound is again representative of the diastolic pressure; however, the
heard represents the systolic blood pressure. measurement of diastolic pressure is inconsistent and
A change in the sound or a second sound may be unreliable. Therefore, when using the Doppler in
noted as the pressure drops. This is theoretically veterinary medicine, only the systolic pressure is

34 D.S. Foy