The document outlines the learning objectives and clinical applications of the Ankle Brachial Index (ABI) test, which is a noninvasive method for detecting peripheral arterial disease (PAD) through the comparison of blood pressure measurements at the ankle and arm. It highlights the sensitivity, specificity, and limitations of the ABI, including its inability to determine the exact location of arterial stenosis and risks of false positives in certain conditions. The document also discusses risk factors for PAD and presents clinical signs indicating the severity of arterial insufficiency.

2.  At the end of the class the students will be able to
Define Ankle brachial index, limitation of ankle brachial
index, risks factors and clinical implications

3. SR.NO LEARNING
OBJECTIVES
DOMAIN LEVEL CRITERIA
1 Define Ankle brachial
index
Cognitive &
psychomotor
MUST KNOW
2 limitation of ankle
brachial index
Cognitive &
psychomotor
MUST KNOW
3 risks factors Cognitive &
psychomotor
MUST KNOW
4

4.  The Ankle brachial pressure index ABPI is the
ratio of the systolic blood pressure measured at
the ankle to that measured at the brachial artery.
 It is a noninvasive, Simple, Valid,reliable &
effective test which is used to detect lower
extremity Peripherial arterial disease PAD to
measure the severity of atherosclerosis in the
legs.

5.  It is not appropriate to detect PAD because of
possibility of false negative findings
 Lower extremity Peripherial arterial disease PAD
is a frequent, chronic ,progressive vascular
disease and associated with significant morbidity
& mortality
 Risk factors PAD are advanced >70 yrs,
smoking,past and present diabetes, family history
of cardivascular disease.

6.  The ABI is also used as a prognostic marker for
cardiovascular events in the absence of symptoms of
PAD
 INDICATIONS:
 Detection of PAD in all patients who present with
symptoms:
 Pain that restrict walking, ischemic pain at rest and
signs ( reduced or absent pedal pulses on palpation,
skin that is cool ,shiny, hairless or thick, thickening of
nails, abnormal capillary, pallor of distal extremity on
elevation, leg pain and tissue ulceration.

7.  Measuring ABI to detect peripheral artery disease
is a more sensitive and reliable test compared to
palpation of a pedal pulse, especially in patients
who are obese or who have significant edema.
 The ABI can provide also reliable information
about the severity of the disease
 It can exclude other causes of calf pain: spinal
stenosis, venous, raynaud phenomenon and
popliteal artery entrapment.

8.  Patients with PAD are frequently asymptomatic,
most commonly they have atypical leg pain and a
few present with typical claudication.
 ABI should be conducted on patients presenting
with risk factors to detect PAD so that therapeutic
interventions known to diminish their increased
risk of MI, stroke & death

9.  The ankle brachial pressure index ABPI is a non
invasive method for detecting or rulling out the
presence of peripheral artery disease.
 ABPI is a calculation of the ratio of the patients
systolic blood pressure at their ankle to the
systolic pressure in their arm.
 ABPI is generally between 1.0-1.4 in healthy
people i.e the systolic pressure at the ankle is
greater than the systolic pressure at the arm

10.  An abnormally low ABPI value i.e < 0.9 has a
sensitivity of 79-95% and specificity of
approximately 95% for peripheral artery disease.
 ABPI provides an indication of disease severity
and the urgency of referral.
 The presence of ischemic rest pain suggest
increased severity of peripheral artery disease
and an increased risk to the limb.

11.  Patients with ischemic rest pain often present with a
burning pain in the arch or distal foot that occurs
when their feet are elevated eg: in bed and resolves
when they place their feet on the floor
 An ABPI <0.4 indicates the patient has critical limb
ischemia
 This is a potentially life threatening condition
characterized by severly reduced circulation,
ischemia rest pain and tissue loss due to gangrene.

12.  The following equipment is recommended for
measuring the ankle brachial pressure index:
 A hand held portable Doppler device with a
frequency of 8-10 Hz although 5 Hz probes may
be better for patients with significant ankle edema.
 A sphygmomanometer
 Ultrasound transmission gel

13.  With the patient in a supine position:
 Place the blood pressure cuff approximately two
to three cm above the antecubital fossa for the
brachial pressure and approximately 5 cm above
the medial malleolus for ankle pressure
 The Doppler probe should detect a clear arterial
pulse before the cuff is inflated.

16.  Inflate the cuff slowly until the systolic pressure is
indicated by the disappearance of the Doppler
sound
 Divide the ankle systolic pressure detected at the
posterior tibial artery by the brachial pressure.
 If the patients ABPI is<0.9 then this indicates they
have peripheral artery disease and additional
measurements are recommended to increase the
accuracy of the assessment of disease severity

17.  Divide the highest ankle systolic pressure in each
of the posterior tibial and dorsalis pedis arteries in
both feet by the highest brachial systolic pressure
from each arm , the lowest resulting value is the
patients overall ABPI.
 The measurement may not be possible in all
patients as 12% of the general population has a
congenital absence of the dorsalis pedis pulse.

18.  ABPI for each leg is obtained by dividing the highest
ankle systolic blood pressure of dorsalis pedis or
posterior tibial artery by the highest of left and right
arm brachial systolic blood pressure
 ABPI=
 RISK FACTORS PAD:
 Old age
 Smoking past, present
 Diabetes
 Hypertension
 Renal function
HIGHER OF EITHER THE DORSALIS PEDIS OR
POST TIBIAL PRESSURE/HIGHER OF
BRACHIAL PRESSURE

19.  LIMITATION OF ABPI
 The Doppler device that is used in measurement
of ABPI indicates the velocity of blood flow and
this is related to blood volume
 The technique is unable to determine the exact
location of a patients arterial stenosis or occlusion
 ABPI can be falsely elevated in patients with
calcification of medial arteries eg in diabetes,
renal dysfunction ,RA

20.  Arterial insufficiency refers to a lack of adequate
blood flow to a region of the body
 PVD is a general term used to describe any
disorder that interfers with arterial or venous blood
flow of the extremities
 Factors that lead to PVD owing to arterial
insufficiency include smoking, cardiac disease
,Diabetes, hypertension ,renal disease and
elevated cholestrol, sedentry lifestyle are related
contributers in the cycle of disease and vessels
obstruction

21.  The damaged caused by these factors is reflected in
structual changes in the walls of arteries ,causing
abnormal blood flow
 Arteriosclerosis: thickening ,hardnening, loss of
elasticity of arterial walls
 Atherosclerosis the most common forms of
arteriosclerosis associated with damage to the
endothelial lining of the vessels and the formation of
lipid deposits, eventually leading to plaque formation.

22.  Thromboangitis obliterans (Buerger’s disease):
inflammation leads to arterial occlusion and tissue
ischemia especially in young men who smoke.
 Raynaud’s disease: a functional vasomotor
disease of small arteries and arterioles
 Ulceration : a peripheral sign of a long standing
disease process ,arterial ulcers are associated
with arterial insufficiency

23.  CLINICAL PRESENTATION:
 Most frequently located on the LE’S : Lateral
malleoli, dorsum of feet, toes
 When wounds are present on an ischemia limb,
atherosclerotic occlusion of the peripheral
vasculature is almost always present
 The majority of patients with arterial insufficiency
also have diabetes.

24.  Tropic changes are present and include abnormal
nail growth, decreased leg and foot hair , dry skin
 Skin is cool upon palpation
 Wounds are painful and patient may describe pain
in the leg and feet

25.  Wound base is necrotic and pale, lacking
granulation tissue.
 Skin around the wound may be black ,gangrenous
 Other signs of arterial insufficiency will be evident:
decreased pulses , pallor on elevation

26.  Painful cramping or aching of the LE during walking is
the most common complaint in patients with chronic
arterial occlusion of the LE’S.
 The pain is caused by intermittent claudication that
occurs when exercising muscle are not receiving
blood perfusion needed for normal function.
 Patients should be examined for other signs of
arterial insufficiency if intermittent claudication is
occuring

27.  Rest pain that develops at night awakens the
patient or requires analgesics for relief is
considered more severe than claudication.
 Diabetes will contribute to slower healing times
and difficulty fighting infection

28.  The ABI is a test designed to examine the
vascular system
 >1.2 : arterial disease diabetes
 1.19-0.95: normal
 0.94-0.75: mild arterial disease+ intermittent
claudication
 0.74-0.50: moderate arterial disease + rest pain
 <0.50 : severe arterial disease.

29.  What is ankle brachial Index?
 What are the limitation of Ankle brachial index?

30.  KISNER
 CASH

31. THANK YOU