Download Smoking can cost an arm and a leg KEY

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Smoking Can Cost You an Arm and a Leg! – 40 Informal Points
Introduction
By this point in your life, you are well aware of the dangers of smoking. From simple physical changes such as
yellow teeth and stinky breath to full-scale disease such as throat or lung cancer, the effects of smoking are
anything but glamorous. But did you know that smokers are at an increased risk for losing a limb? This fact
alone should be enough to make anyone quit. Smoking might literally cost a person an arm or a leg.
As blood is being pushed through the body, it presses against the sides of the vessels. As you learned in PBS,
we can measure this blood pressure to get an idea of the stress placed upon the vessels. In a normal blood
pressure reading of 120/80 the top number is called the systolic pressure and the bottom number is called the
diastolic pressure. Systole is the Greek word for “contracting” and diastole is the Greek word for “dilation.” This
means that the first number in a blood pressure corresponds to pressure when the vessel is contracted; the
second number corresponds to the pressure when the vessel is open, or dilated. Normally, we take blood
pressure readings in our arms. Similar methods can be used to measure blood pressure in other vessels in the
body and to monitor overall blood flow.
As you complete this activity, you will learn how simple measures of pressure in blood vessels can pinpoint
problems in blood flow and how body systems work together to maintain blood pressure and volume. In this
activity, you will investigate the symptoms of a fictional patient, evaluate diagnostic tests and recommend
medical interventions as you play the role of John’s doctor.
Procedure
Part I: Tired of Tingling
John’s Health History: John Jones has always been relatively healthy. He eats well, but he has smoked a
pack a day on and off for 30 years. John was an athlete in college and even though he is in his 50’s now, he
still gets out running or walking at least twice a week. Lately, he has noticed cramping in his right calf when he
exercises. The pain goes away once he stops and rests, but John is starting to think that something might be
wrong. John also reports frequent tingling in his leg, almost like it is falling asleep.
1. With your partner, analyze information provided in John’s health history given above. Use your own prior
knowledge and information you find on the Internet to answer the following questions:
o What are some possible causes of John’s leg pain?
Smoking has harmed his cardiovascular system. In the lungs not as much oxygen is being
absorbed due to the black tar buildup. Vessels have become hardened and blocked by
plaque. Circulation becomes poor which means oxygen delivery is poor which reduces or
eliminates functioning.
o What do you think is the most likely cause of John’s leg pain? Describe this condition.
PAD (Peripheral Artery Disease). Peripheral artery disease (PAD) is a narrowing of the
peripheral arteries to the legs, stomach, arms, and head - most commonly in the arteries of
the legs. PAD is similar to coronary artery disease (CAD). Both PAD and CAD are caused
by atherosclerosis that narrows and blocks arteries in various critical regions of the body.
o How might smoking be related to John’s leg pain?
Smoking has harmed his cardiovascular system. In the lungs not as much
oxygen is being absorbed due to the black tar buildup. Vessels have become
hardened and blocked by plaque. Circulation becomes poor which means oxygen
delivery is poor which reduces or eliminates functioning.
o What basic test(s) can be performed to confirm your diagnosis? What do these tests
measure?
Physical Exam:
During the physical exam, your doctor will look for signs of P.A.D. He or she may
check the blood flow in your legs or feet to see whether you have weak or absent
pulses.
Your doctor also may check the pulses in your leg arteries for an abnormal
whooshing sound called a bruit. He or she can hear this sound with a stethoscope. A
bruit may be a warning sign of a narrowed or blocked artery.
Your doctor may compare blood pressure between your limbs to see whether the
pressure is lower in the affected limb. He or she also may check for poor wound
healing or any changes in your hair, skin, or nails that may be signs of P.A.D.
Diagnostic Tests:
Ankle-Brachial Index
A simple test called an ankle-brachial index (ABI) often is used to diagnose P.A.D.
The ABI compares blood pressure in your ankle to blood pressure in your arm. This
test shows how well blood is flowing in your limbs.
ABI can show whether P.A.D. is affecting your limbs, but it won't show which blood
vessels are narrowed or blocked.
Part II: Under Pressure
In Part I, you learned that John may be at risk for peripheral vascular disease (PVD), specifically peripheral
artery disease (PAD). One simple test for diagnosing PAD is called the ankle brachial index (ABI).
2. Review the physiology of blood pressure. Use the Internet to help you answer the following:
o List and describe at least three body systems that help in the regulation and control of
blood pressure.
Endocrine – hormones cause vessels to vasodilate or vasoconstriction
Urinary – regulates water retention or excretion which directly affect blood volume
Circulatory – heart rate
o Draw a feedback loop that shows one way your body responds to an increase in blood
pressure. Make sure to mention all the organ systems, organs, or hormones involved in
restoring balance.
3. With your partner, use the Internet to answer the following:
o What is the ankle brachial index (ABI) and how is it computed?
The ankle-brachial index (ABI) result is used to predict the severity of peripheral arterial disease (PAD).
A slight drop in your ABI with exercise means that you probably have PAD. This drop may be important,
because PAD can be linked to a higher risk of heart attack or stroke.
An ABI is calculated for each leg. The ABI value is determined by taking the higher pressure of the 2
arteries at the ankle, divided by the brachial arterial systolic pressure. In calculating the ABI, the higher of
the two brachial systolic pressure measurements is used.
o How does ABI relate to blood pressure?
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).
o What is the difference between systolic and diastolic pressure? To compute an ABI, we use
only the systolic blood pressure.
Blood pressure is usually reported as two values – systolic pressure, the pressure in the
arteries when the ventricles are at maximum contraction, and diastolic pressure, the
pressure in the arteries when the ventricles are relaxing.
o John is worried about pain during this test. What can you tell him to calm his nerves?
Only blood pressure is taken. Nothing is painful. The gel may be cold.
Part III: Analyzing an ABI
The ABI is a painless measurement that evaluates the circulation in your legs. In this simple test, the doctor
listens to the flow of blood and measures the blood pressure in both the arms and the feet. Normally, these two
pressures should be about equal. A significantly lower pressure in the ankle usually indicates that there is a
problem with blood flow in the legs.
Doppler ultrasound uses reflected sound waves to assess blood flow through a vessel. In this activity, you will
use a Doppler device to listen to blood moving through the vessels of the arm and ankle, and use systolic
pressure values to compute an ABI.
John finally agreed to go in for simple testing. The report from his ABI testing is found on the next page.
4. Compute John Jones’ ABI.
Right ABI: 60/142 = 0.42
Left ABI: 129/142 = 0.91
5. Work with your partner to analyze your findings, discuss treatment and answer the following:
o What do the values for ABI imply about John’s legs?
John is in the mild-moderate disease category.
o What is most likely occurring inside John’s leg to cause this increase in peripheral
pressures? How does this relate to smoking?
Smoking caused the vessels to harden and plaque to build up in the arteries – arteriosclerosis. The more plaque
the higher the pressure because the opening for blood flow is narrowed.
o What is arteriosclerosis? What is the difference between arteriosclerosis and
atherosclerosis?
Arteriosclerosis occurs when the blood vessels that carry oxygen and nutrients from your heart to the rest
of your body (arteries) become thick and stiff — sometimes restricting blood flow to your organs and
tissues. Healthy arteries are flexible and elastic, but over time, the walls in your arteries can harden, a
condition commonly called hardening of the arteries.
Atherosclerosis is a specific type of arteriosclerosis, but the terms are sometimes used interchangeably.
Atherosclerosis refers to the buildup of fats, cholesterol and other substances in and on your artery walls
(plaques), which can restrict blood flow.
o How can atherosclerosis be linked to PAD?
Clogged arteries increase pressure which over time leads to disease.
o What other tests can be performed to confirm this diagnosis?
Physical Exam:
During the physical exam, your doctor will look for signs of P.A.D. He or she may
check the blood flow in your legs or feet to see whether you have weak or absent
pulses.
Your doctor also may check the pulses in your leg arteries for an abnormal
whooshing sound called a bruit. He or she can hear this sound with a stethoscope. A
bruit may be a warning sign of a narrowed or blocked artery.
Your doctor may compare blood pressure between your limbs to see whether the
pressure is lower in the affected limb. He or she also may check for poor wound
healing or any changes in your hair, skin, or nails that may be signs of P.A.D.
o If tests confirm that John has a clot in his leg, what treatment options may help relieve his
pain and save his leg?
The blood clot can break free and travel to the lungs if not treated, where it blocks blood flow and
causes a condition known as pulmonary embolism. Blood thinners and clotbusters are medications
intended to dissolve blood clots. Clotbusters are dangerous, however, because they can cause
extensive bleeding, so they are used only when blood thinners have failed. An implanted filter may be
used to catch the blood clot before it can block blood flow to the lungs.
Conclusion Questions
1. What is your ABI? What does this value tell you about your risk of peripheral artery disease?
2. Explain how PAD might impact other body systems.
Over time, plaque can harden and narrow the arteries. This limits the flow of oxygen-rich blood to
your organs and other parts of your body. P.A.D. usually affects the arteries in the legs, but it also
can affect the arteries that carry blood from your heart to your head, arms, kidneys, and stomach.
3. How do the chemicals in smoke relate to the development of atherosclerosis?
The chemicals in tobacco smoke harm your blood cells. They also can damage the function of your heart
and the structure and function of your blood vessels.
4. Why do you think diabetics are also at increased risk for PAD?
Diabetics have a large amount of glucose in their blood, which can damage the walls of
arteries and make them more susceptible to PAD.
5. Explain why untreated PAD can lead to the loss of a leg. Make sure to mention the specific arteries of the
leg.
PAD can damage and block the blood flow in the femoral arteries, or the arteries that feed
blood to the femur and rest of the leg. If left untreated, PAD can lead to the total blockage of
an artery, which results in a total lack of blood flowing to the leg which would cause cell death
and the loss of the leg.
6. Explain how the endocrine system and the kidneys help play a role in regulating blood pressure.
The kidneys help balance the water levels in the blood. They can either pull out more or less
water with would help the blood thicken or be more dilute. The endocrine system, specifically
the pituitary gland, releases the hormone that tells the kidneys to release more or less anti diuretic hormone which will help thicken the blood or dilute it.