EMBOLISM
may be used as a diagnostic test for
mul-
tiple myeloma
,
a bone marrow tumour
that produces abnormally high blood
levels of a specific
antibody
(a protein
manufactured by the immune system).
elephantiasis
A disease that occurs in the tropics and
is characterized by massive swelling of
the legs, the arms, and, in men, the
scrotum (the pouch behind the penis
that contains the testes). There is also
thickening and darkening of the skin.
Most cases of elephantiasis are due to
chronic lymphatic obstruction caused
by
filariasis
(a worm infestation).
elimination diet
A dietary programme used to identify
a
food allergy
or
food intolerance
.
Test
foods, such as milk, are gradually omit-
ted from the diet one at a time to see if
they are responsible for the symptoms.
(See also
exclusion diet
. )
ELISA test
A laboratory blood test used in the diag-
nosis of infectious diseases. ELISA stands
for enzyme-linked immunosorbent assay.
(See also
immunoassay
.)
elixir
A clear, sweetened liquid, w hich often
contains alcohol, that forms the basis
of many liquid medicines,
such as
cough remedies
.
ellipsoidal joint
A type of mobile
joint
,
such as the wrist
joint, that allows all types of movement
except full rotation.
Eltroxin
A brand name for
levothyroxine
,
a syn-
thetic
thyroid hormone
.
emaciation
Abnormal thinness or wasting away of
the body, w hich may be the result of a
variety of conditions including
malnutri-
tion
,
worm infestation
,
or diseases such as
tuberculosis
or
cancer
.
embolectomy
Surgical removal of an embolus (a frag-
ment of material, often a blood clot,
that is carried in the bloodstream and
has blocked an
artery
;
see
embolism
) .
There are two methods of embolec-
tomy. In one procedure, an incision is
made in the affected artery and the
embolus is removed through a suction
tube. In balloon embolectomy, a
balloon
catheter
(a flexible tube with a balloon
at its tip) is passed into the affected
blood vessel, to just beyond the embo-
lus. The balloon is inflated and the
catheter is withdrawn from the body,
bringing the embolus out with it.
embolism
Blockage of an
artery
by an embolus
(a fragment of material carried in the
bloodstream). An embolus may consist
of various
substances.
It
is
usually
formed from a blood clot. Other sub-
stances that may form an embolism
include a bubble of air or other gas; a
piece of tissue or tumour; a clump of
bacteria, bone marrow, cholesterol, or
fat; or, rarely, amniotic fluid forced into
a woman’s circulation during
childbirth
.
TYPES
A blood clot that has broken off from a
larger clot elsewhere in the circulation
is the most common type of embolus.
Pulmonary embolism
is a disorder that
may be due to a blood clot. The condi-
tion is usually the result of a fragment
breaking off from a deep vein thrombo-
sis (see
thrombosis, deep vein
)
and being
carried via the heart to block an artery
supplying the lungs. Pulmonary embol-
ism may cause sudden death. Blood
clots may form inside the heart after a
myocardial infarction
(heart attack), or in
the atria (upper chambers of the heart)
in
atrial fibrillation
,
and then travel to
the brain. This results in a cerebral
embolism, w hich is an important cause
of
stroke
(damage to part of the brain
due to interruption to its blood supply).
Air embolism
,
in w hich a small artery
is blocked by an air bubble, is rare. Fat
embolism, in w hich a vessel is blocked
by fat globules, is a possible complica-
tion of a major
fracture
of a limb; it
occurs when fat is released from the
marrow of the broken bone. Amniotic
fluid embolism occurs during labour
or immediately after delivery of the
baby. This rare complication of child-
birth is often fatal.
SYMPTOMS
Symptoms of an embolism depend on
the site of the embolus. Pulmonary
embolism
can lead to breathlessness
and chest pains. If the embolus lodges
in the brain, a stroke may occur, affect-
ing speech, vision, or movement. If an
embolism blocks an artery to the leg,
the lim b w ill become painful and turn
pale. If left untreated,
gangrene
(tissue
death) may develop.
In serious
cases
of fat embolism,
heart and breathing rates rise dramati-
cally and there may be restlessness,
confusion, and drowsiness.
E
TYPES OF EMBOLISM
Embolisms are named after the part of
the circulation affected by the embolus
involved (for example, a fat embolism
is caused by fat globules, sometimes
released from a bone fracture). When
an embolus is released, it is carried
through branches of an artery until it
becomes lodged. Blood is prevented
from reaching parts of the body beyond.
L e f t s u b c l a v i a n
a r t e r y
B r a c h i a l a r t e r y
H u m e r u s
E x t e n t o f b l o o d
f l o w in t o a r m
Angiogram of embolism in the arm
This X-ray was taken after injection of a contrast
medium into the blood vessel. It shows the
obstruction, by an embolus, ofthe normal flow
of blood through the subclavian artery and the
brachial artery beside the humerus.
C e r e b r a l e m b o l i s m
____
A b l o c k a g e o f o n e o f t h e
a r t e r i e s t h a t s u p p l y b l o o d
t o t h e b r a i n ; i t i s o n e o f
t h e m o s t c o m m o n c a u s e s
o f s t r o k e .
P u l m o n a r y e m b o l i s m .
A b l o c k a g e o f o n e o f t h e
a r t e r i e s t h a t s u p p l y b l o o d t o
t h e lu n g s . T h i s m a y c a u s e
c h e s t p a i n , b r e a t h l e s s n e s s ,
a n d s u d d e n d e a t h .
A m n i o t i c f l u i d e m b o l i s m
T h e e s c a p e o f s o m e o f t h e
f l u i d t h a t s u r r o u n d s t h e
b a b y in t h e u t e r u s in t o t h e
m o t h e r ’s c i r c u l a t i o n . T h is
m a y c a u s e b l o c k a g e o f a n
a r t e r y in o n e o f h e r l u n g s .
E m b o l i s m in l e g
A n e m b o l i s m m a y b l o c k
o n e o f t h e a r t e r i e s t h a t
s u p p l y b l o o d t o t h e le g .
G a n g r e n e m a y o c c u r
b e l o w t h e b l o c k a g e .
261
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