CHOLESTASIS
cholelithiasis
See
gallstones.
cholera
An infection of the small intestine by
the bacterium V
ibrio cholerae
. The dis-
ease causes profuse watery diarrhoea,
w hich can lead to dehydration and
death in severe untreated cases.
CAUSE AND INCIDENCE
Infection is acquired by ingesting con-
taminated food or water. Outbreaks of
the disease occur regularly in northeast
India, but worldwide cholera is con-
trolled by sanitation.
SYMPTOMS
Cholera starts suddenly, between one
and five days after infection, with diar-
rhoea that is often accompanied by
vomiting. More than
500
m l of fluid
may be lost each hour and, if this fluid
is not replaced, severe dehydration and
then death may occur w ithin hours.
The fluid loss is caused by the action of
a toxin produced by the cholera bac-
terium
that
greatly
increases
the
passage of fluid from the bloodstream
into the large and small intestines.
TREATMENT
Treatment
is with
water
containing
salts and sugar (see
oral rehydration ther-
apy
) and, in severe cases, by
intravenous
infusion. Antibiotic drugs
can shorten the
period of diarrhoea and infectiousness.
After
adequate
rehydration,
affected
people usually make a full recovery
from the infection.
PREVENTION
Cholera is controlled worldwide by the
improvement of sanitation, and in par-
ticular by ensuring that sewage is not
permitted to contaminate water sup-
plies
used
for
drinking. Vaccination
against cholera is not recommended.
Travellers
planning
to visit
cholera-
infected areas are advised to consume
only water that has been boiled, or bot-
tled drinks from reliable sources.
cholestasis
Stagnation of
bile
in the small
bile ducts
w ithin the liver, leading to
jaundice
and
liver disease. The obstruction to the
flow of bile may be intrahepatic (with-
in the liver) or extrahepatic (in the bile
ducts outside the liver).
CAUSES
Intrahepatic cholestasis may develop as
a result of viral hepatitis (see
hepatitis,
viral
) or as an adverse effect of various
drugs. The flow of bile w ill improve
gradually as the inflammation from
hepatitis subsides or when a causative
drug is discontinued.
The bile ducts outside the liver can
become blocked by abnormalities such
as gallstones or tumours (see
bile duct
obstruction
). Rarely, the ducts are absent
from birth (see
biliary atresia).
TREATMENT
Bile duct obstruction and biliary atresia
are often treated surgically to ensure or
restore the free passage of bile from the
liver to the duodenum.
CHOLECYSTECTOMY
Surgery to remove the gallbladder
(cholecystectomy) can be performed
conventionally or laparoscopically. The
procedure is performed under general
anaesthesia; it is most often carried
out when the gallbladder has been
found to contain gallstones.
Laparoscopic cholecystectomy
(pictured here), despite taking twice
as long as conventional surgery
(about two hours), has the advantage
of requiring only small incisions and
allowing most patients to make a full
recovery in 7 to 10 days.
Sites of
incision
L iv e r
S t o m a c h
G a l l b l a d d e r
Cholecystogram of the gallbladder
Gallstones, which become more prevalentwith
age, are revealed bya cholecystogram (X-ray
image ofthe gallbladder).
G a l l b l a d d e r
S u c t io n i n s t r u m e n t
Procedure for cholecystectomy
The abdominal cavity is inflated with gas to
provide a clear view, then a laparoscope fitted
with a video camera is introduced through a
small incision. Further instruments are passed
through other incisions. While watching the
monitor, the surgeon removesthe gallbladder,
ensuring that there is no leakage from the bile
duct or blood vessels.
C
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