Use of Doppler in Wound Care
Management’
The Institute of Community Health
Nursing
17/05/2017
Theory of ABPI
• The APBI is the ratio of the systolic B/P
measured at the ankle to that measured at
the brachial artery (arm)
Theory of ABPI
What is an Ankle Brachial Pressure Index?
• The ankle-brachial pressure index (ABPI) or
ankle-brachial index (ABI) is the ratio of the
blood pressure at the ankle to the blood
pressure in the upper arm (brachium)
• Compared to the arm, lower blood pressure in
the leg is an indication of blocked arteries due
to peripheral artery disease (PAD)
Theory of ABPI
• Systolic B/P in the legs is equal (or slightly
greater than) systolic B/P in the arms (= 1)
• Circulatory system is a closed system
• When an arterial stenosis (or narrowing) is
present, a reduction in pressure(B/P) occurs
distally to the lesion. (= 0.9)
• This can be detected by ABPI or Doppler
Theory of ABPI
• ABPI is an objective assessment in identifying
arterial disease.
• Ratio of the ankle to the brachial systolic
pressure
• Uses a hand held Doppler ultrasound probe
instead of stethoscope to determine the
systolic reading.
• Divide the ankle systolic pressure(highest) by
the (highest)brachial systolic pressure
Theory of ABPI
Formula
Ankle The highest systolic reading in the ankle
Brachial The highest systolic reading in the arm
Theory of ABPI
Sounds
• Doppler probe makes audible the pressure at
which the systolic pulse return
• Normal “ triphasic” signal
• This represents the three phases of arterial
flow
• Three distinct sounds heard during a single
cardiac cycle (Donnelly et al 2000)
Theory of ABPI
Phases
1. Blood rushes forward
2. Reverses briefly
3. Propels forward again
This is echoing the elastic wall of the main artery
(Aorta) leaving the heart as it stretches and
contracts
Theory of ABPI
Sounds
• Triphasic waveform- all three sounds are
present
• Biphasic- the first two are present
• Monophasic- first one is observed
Theory of ABPI
Sounds
• Important to understand what the three
sounds represent as increasing artery stenosis
results in progressive dampening of the
waveform and the development of
monophasic sound.
(Vowden et al 2004)
Assessment
Assessment
• Important to assess the arterial supply to the
limbs prior to applying compression therapy
• Arterial disease can co-exist in approximately
10-20% with lower limb ulceration (Vowden
2001)
• ABPI should be done at the beginning of
treatment and every three months(or as
indicated) while compression therapy is used.
Assessment
• ABPI using a Doppler probe is a reliable way of
detecting evidence of arterial insufficiency
• Also shows if arterial insufficiency is
developing
• ABPI result itself is NOT a diagnostic indicator
of venous disease
• Guides the clinicians decision making towards
safe levels of treatment
Danger!!
• Failure to recognise arterial disease or
incorrect interpretation of ABPI results can
result in the unsafe application of high
compression therapy
• Pressure damage
• Exposed tendons
• Tissue damage
• Tissue necrosis
Taking a reading
• Ensure that client is lying flat for 15-20-minutes
• Semi reclined if patient cannot lie flat due to medical
conditions
• Take the brachial systolic pressure reading on both arms
and record the highest.
• Place the cuff on the lower limb protecting the ulcer site
• Take the systolic reading using the Dorsalis pedis and
posterior tibial artery.
• Record the higher of the two
• Calculate the reading by dividing the highest ankle systolic
by the highest brachial systolic.
Pedal Pulses
• Palpation of pulses not a fail safe way to
determine arterial sufficiency
• In one study, lack of pedal pulses had a
positive predictive value for significant
arterial disease in only 35% of clients.
• 37% with palpable pedal pulses were found
to have significant arterial disease
(Moffatt, O Hare 1995)
Pedal Pulses
• Dorsalis pedis congenitally absent in 12% of
population
• Oedema can make pedal pulses hard to
palpate
• Clients with intermittent claudication can
have palpable pulses at rest that disappear on
walking
• Diabetics can have pulses and have significant
small vessel disease
Pulse Points
• Arm… Brachial Artery in both arms
• Limbs… Dorsalis Pedis, Posterior Tibial pulse
ABPI
Readings
• ABPI between 0.92 and 1.30 = normal
• Greater than 1.30= calcified artery, false result
• Greater than 0.8= May be safe for full
compression (comprehensive history and
physical examination)
• Between 0.5 and 0.8= reduced compression
• Mixed ( ABPI < 0.5)- Urgent referral to vascular
specialist-NO COMPRESSION
Extrinsic and Intrinsic factors
•
•
•
•
•
•
•
•
Ambient Temperature
Age
Ethnicity
Height
Pulse volume
Smoking
Medication
White coat syndrome
Extrinsic and Intrinsic factors
• Take into consideration
• Make reasonable adjustments
• May have negligible effects on the diagnostic
ability of ABPI
Cuff size and position
• Appropriate to limb size
• Width should be at least 40% of the limb
circumference
• Standard and large cuff recommended
• Above the ankle and above the elbow
• Pulse point accessible
• May be easier to have cuff upside down so
that the tube is away form the pulse point
Equipment
• Hand held Doppler (or equivalent)
• Probe.. 8mgHz for lower limb assessment,
5mhHz if there is a lot of oedema
• Cuff
• Sphygmomanometer
• Ultrasound gel
• Tissues
• Cling film or equivalent to cover ulcer
Contra Indications
• Recent DVT ( within 2 weeks )
• Sickle cell anaemia (refer)
• Infection ( should be treated prior to ABPI and
application of compression)
• Caution with Diabetic due to hardening of
arteries
Issues to look out for?
• Cuff repeatedly inflated or inflated for long
periods
• Can cause ankle pressure to fall and affect the
reading
Issues to look out for?
• Cuff not at the ankle
• Ankle systolic pressure not measured,
pressure is usually higher than ankle pressure
Issues to look out for?
• Pulse is irregular or the cuff is deflated too
rapidly
• True systolic reading may be missed
Issues to look out for?
• Vessels are calcified, limbs are large, fatty,
oedematous, cuff too small or limbs
dependant
• Inappropriately high readings are obtained
Issues to look out for?
• Central systolic pressure may influence
“normal range” for ABPI
• Has the patient got Hypertension?
Conclusion
• Once the procedure is followed correctly with
proper consideration give to technique, risk
factors and data interpretation, ABPI is a safe
and reliable method of monitoring arterial
disease
Reference
• http://www.medicinenet.com/peripheral_vas
cular_disease/article.htm
• Worboys F, (2006) How to obtain the resting
ABPI in leg ulcer Management : Wound
Essentials (Technical Guide)
• VowdenP, Vowden K (2001) Doppler
Assessment and ABPI; Interpretation in the
management of leg ulceration. World Wide
Wounds