·
It is necessary
to auscultate the abdomen prior to percussion and palpation because
percussion may alter the frequency and the intensity of bowel sounds. The
absence of bowel sounds is not established unless no sounds are detected during
5 min of continuous auscultation. Percussion is an important means of assessing
the size and density of abdominal organs as well as detecting fluid or air in
the abdomen.
·
The HemOccult Slide Test (Smith-Kline Diagnostics)
detects the presence of hemoglobin in feces. False-positive results can be
produced by the dietary intake of rare beef or fruits and vegetables that
contain peroxidases. This effect is seen mainly in tests performed on
rehydrated stool specimens. Oral iron preparations also have been implicated in
some studies but not in others. False-positive results can occur due to blood
from sources other than colorectal carcinoma, such as gastric blood loss caused
by nonsteroidal antiinflammatory drugs (NSAIDs).
·
AST is elevated by twice as much as ALT in alcoholic hepatitis
because alcohol inhibits ALT synthesis more than AST synthesis.
·
Common MANEUVERS/SIGNS and their
associations:
1. Cullen sign, Turner sign: hemorrhagic
pancreatitis
2. Murphy sign: acute cholecystitis
3. Caput medusae: liver cirrhosis
4. Courvoisier gallbladder: cancer of the biliary
tract or pancreatic head
5. Kehr sign: splenic rupture
6. Obturator test, reverse psoas maneuver:
retrocecal appendicitis
7. Markle sign
(jar tenderness): specific for peritonitis
8. Succussion splash:
intestinal obstruction or gastric dilatation
·
CMV esophagitis
often is only one component of a generalized CMV infection, and some 20% to 40%
of patients with CMV esophagitis have systemic symptoms. In contrast, candidal and HSV esophagitis usually are not
associated with infection in other organs, and systemic symptoms caused by
these pathogens are uncommon.
·
Pancreatic
necrosis is defined as an absence of enhancement of pancreatic
parenchyma after the infusion of intravenous contrast on contrast-enhanced CT
(CECT). Acute necrotizing pancreatitis
is defined by the presence of necrosis on CECT; it is subclassified as either
sterile necrosis or infected necrosis. Acute
interstitial pancreatitis is defined by the absence of these CECT
findings of necrosis. Finally, pancreatic
abscess is defined as a circumscribed collection of pus containing
little necrotic tissue. What was formerly called infected pseudocyst is now
termed pancreatic abscess. The term phlegmon was
abandoned, because no consensus could be reached as to its definition.
·
The serum amylase
level may be normal in some patients with acute pancreatitis
associated with alcohol use
and in those with hyperlipidemic
pancreatitis (marked elevations in the triglyceride level can interfere with
the laboratory assay for amylase); the serum amylase level may be normal in
patients with acute pancreatitis if the measurement is made several days after the onset of symptoms.
Measurement of serum lipase is often used as an adjunct to or in place of serum
amylase as a confirmatory test.
·
A low serum
trypsinogen level (< 20 ng/ml) is highly specific for chronic
pancreatitis, but the trypsinogen level only drops to this level in advanced
disease. The bentiromide test
utilizes the measurement in urine of a metabolite that can only be produced by
the action of pancreatic enzymes. A 72-hour
stool collection for fat is the gold standard to detect steatorrhea.
Steatorrhea is only seen in far-advanced chronic pancreatitis. Fecal levels of elastase and chymotrypsin are
reduced in more advanced cases of chronic pancreatitis. Direct pancreatic
function tests involve placing a tube into the duodenum to collect pancreatic
juice. This test directly measures pancreatic output of enzymes or bicarbonate
after stimulation with a secretagogue. These tests are the most sensitive tests
available and are able to detect chronic pancreatitis at an earlier stage than
any other test.
·
Besides the commonly seen pseudocysts, a number
of other cystic lesions may occur in the
pancreas, including true cysts and cystic neoplasms. Serous cystic neoplasms are benign, but
mucin-producing cystic neoplasms may
follow a more malignant course. Mucinous cystic neoplasms present as
large cystic collections (cystadenomas and cystadenocarcinomas) and may be
relatively asymptomatic. Most cystic neoplasms occur in middle-aged patients,
particularly women. They are often mistaken for pseudocysts and
inappropriately treated as such. These cystic neoplasms may follow an initially
benign course, but when they undergo malignant degeneration, outcomes are as
poor as in patients with standard adenocarcinoma. The presence of a cystic collection of the pancreas in a middle-aged
(particularly female) patient without a previous history of pancreatitis should
immediately suggest a cystic neoplasm, not a pseudocyst.
·
The organisms that most commonly cause cholangitis are Escherichia
coli, Klebsiella, enterococci, and Bacteroides fragilis. Ceftriaxone
is not recommended in this case because it does not cover enterococci and
has been associated with the development of gallbladder sludge. Treat with
ampicillin-sulbactam.
·
Although sclerosing
cholangitis usually develops in younger men (aged 20 to 50 years),
it is often associated with ulcerative colitis. About 60% of patients will also
have a positive perinuclear antineutrophil cytoplasmic antibody (p-ANCA) test
result. The hallmark finding on ERCP is segmental stenosis of the biliary tree.
Primary biliary cirrhosis is an
autoimmune disease that typically affects women. About 95% of patients have
antimitochondrial antibodies. Both primary biliary cirrhosis and drug-induced
cholestasis cause intrahepatic cholestasis without extrahepatic duct
dilatation.
·
Collagenous sprue
is a rare, devastating disease in which there is a layer
of collagen underneath the enterocytes of the small bowel. The origin of
collagenous colitis is unknown, but it develops in approximately half the
patients who have refractory celiac disease. The symptoms are severe and
include obvious malabsorption. The diagnosis is made on the basis of the
classic histologic picture of villous atrophy and
subepithelial collagen deposition. Therapy for collagenous sprue is
uncertain; some patients respond to steroids. Poor adherence to
gluten-exclusion diet is common.
·
Congenital intestinal
lymphangiectasia: Intestinal lymphangiectasia is often a congenital
condition in which deformed lymphatics impair the transport of
chylomicrons from the enterocytes to the mesenteric lymph
duct. The blockage of lymphatic drainage may result in chylous ascites. Protein-losing enteropathy and lymphopenia are prominent
features. Modest steatorrhea is also present. In the congenital form of
the disease, lymphedema of the legs
or of one leg and one arm is seen. With endoscopic examination, white villi, white
nodules, and submucosal elevations may be noted. The white appearance of the mucosa is undoubtedly caused by
retained chylomicron triacylglycerol. Double-contrast barium x-ray examination
shows smooth nodular protrusions and thick mucosal folds without ulceration. On
histologic examination, dilated lymphatics with
club-shaped villi are seen.
·
Pancreas
transplantation has been shown to prevent or reduce the nephropathy
that often develops in kidney grafts in diabetic patients. The favored
placement of the graft is the right lower
quadrant, with vascular anastomoses to the common iliac artery and
the common iliac vein or portal vein; in simultaneous pancreas and kidney transplantations, the
preferred placement is the left lower quadrant.
·
SKIN FINDINGS IN CONDITIONS THAT
CAUSE GI BLEEDING
|
Associated skin findings
|
|
Pigmented macules on lips, palms, soles
|
|
Melanoma
|
|
Telangiectasias on lips, mouth, palms, soles (Osler-Weber-Rendu)
|
|
Dark, blue soft nodules
|
|
Oral and skin bullae
|
|
Café-au-lait spots, axillary freckles, neurofibromas
|
|
Alopecia; hyperpigmentation of creases, hands, and face
|
|
Spider angiomata, Dupuytren's contracture
|
|
Acanthosis nigricans
|
|
Cutaneous Kaposi's sarcoma
|
|
Skin fragility, keloids, paper thin scars
|
|
Yellow "chicken fat" papules and plaques in flexural areas
|
|
Webbing of neck, purpura, skin nodules
|
·
Basic stool
studies, including bacterial culture and sensitivity, Sudan
stain for fat, Wright's stain for WBCs, test for occult blood, and a
phenolphthalein test for the presence of laxative ingestion, are simple
and quickly obtainable tests that may give valuable results.
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