Diagnostic studies of gi system

1. DIAGNOSTIC STUDIES
of the Gastrointestinal system
PRESENTED BY
BEEMAMOL HUSSAIN
40TH BSC NURSING

2. Diagnostic studies
 Studies are considered to be objective data
 Explain the procedure to the patient and obtain
a written consent form from the patient
 Ask about any known allergies to drugs,
iodine, shellfish or contrast medium
 Monitor the patient closely to ensure adequate
hydration and nutrition during testing period

3.  Close monitoring is needed to prevent
diarrhea from bowel-cleansing procedures and
dehydration from prolonged fluid restriction
 Individualize and make comfortable
adjustments especially for older adults

5. Diagnostic studies
Radiologic studies
Endoscopic studies
Blood chemistries
Liver biopsy
Fecal tests
Liver function tests

6. Radiological studies
Upper Gastrointestinal (GI) Series or Barium Swallow
Small Bowel Series
Lower GI Series or Barium Enema
Ultrasound
Computed Tomography (CT)
Magnetic Resonance Imaging (MRI)
Cholangiography
Nuclear Imaging Scans (Scintigraphy)
Defecography
Gastric emptying breath test (GEBT)
Virtual colonoscopy
Barium X-
Ray studies

7. Barium X-Ray Studies
 A barium X-ray is a radiographic (X-ray) examination of the
gastrointestinal (GI) tract
 used to diagnose abnormalities of the GI tract, such as
tumors, ulcers and other inflammatory conditions, polyps,
hernias, strictures, varices, tumors, foreign bodies and peptic
ulcer in the duodenum or stomach.
 Fluoroscopy is a study of moving body structures—similar to
an X-ray “movie”. A continuous X-ray beam is passed through
the body part being examined, and is transmitted to a TV-like
monitor so that the body part and its motion can be seen in

8. Reasons for performing barium X-ray procedures may include
the following:
 Abdominal pain
 Bleeding from the rectum
 Unexplained vomiting
 Bowel movement changes
 Chronic diarrhea or constipation
 Pain or difficulty swallowing
 Unexplained weight loss
 Unusual bloating
 To detect anatomical abnormalities

9. There are three types of barium X-ray
procedures:
 Barium swallow (also called upper GI series)
 Barium small-bowel follow through
 Barium enema (also called lower GI series)

10. Upper Gastrointestinal (GI) Series or Barium
Swallow
 An upper GI series is an examination of the
esophagus, stomach and duodenal bulb using
barium to coat the walls of the upper digestive
tract so that it may be examined under X-ray
using fluoroscopy.

12. Nursing responsibility
 Explain the procedure to the patient.
 Keep patient NPO for 8-12 hour before procedure.
 Tell patient to avoid smoking after midnight the night before the
study.
 The patient will be asked to drink the contrast medium (barium
liquid).
 The patient will stand behind a machine called a fluoroscope . The
patient may be asked to move in different positions and to hold his
or her breath while the X-rays are taken.
 After x-ray, take measures to prevent contrast medium impaction
(fluids and laxatives).
 Tell the patient that stool may be white up to 72 hrs after test.

13. Small Bowel Series
 A barium small-bowel follow through involves
filling the small intestine with barium liquid
following barium swallow, while X-ray images
are being taken.
 Contrast medium is being ingested and films
taken q20min until medium reaches terminal
ileum.

14. Nursing responsibility
 Explain the procedure including the need to drink
contrast medium and assume various position on
the x-ray table.
 Keep patient NPO for at least 8 h.
 Tell the patient to avoid smoking after midnight
 After the procedure take measure to prevent
contrast medium impaction (fluids, laxatives).
 Tell the patient that stool may be white up to 72 h.

16. Lower GI Series or Barium Enema
 A barium enema involves filling the large intestine
with diluted barium liquid while X-ray images are
being taken. Barium enemas are used to
diagnose disorders of the large intestine and
rectum.
 Contrast medium (barium liquid) is administered
rectally.
 Used to detect the presence of tumors, diverticula,
and polyps.

17. Barium enemas are performed in two ways:
 Single-contrast barium enema - The entire large intestine is
filled with barium liquid. Single-contrast images show
prominent abnormalities or large masses in the large
intestine.
 Double-contrast or air-contrast barium enema - A smaller
quantity of thicker barium liquid is introduced to the large
intestine, followed by air. Double-contrast images show
smaller surface abnormalities of the large intestine, as the air
prevents the barium from filling the intestine. Instead, the
barium forms a film on the inner surface. As it requires the
patient to retain barium, it is not tolerated as well in an older
adult or immobile patient.

18. SINGLE CONTRAST BARIUM
ENEMA
DOUBLE CONTRAST BARIUM
ENEMA

19. Nursing responsibility
 Administer clear liquid diet one to two days prior to the
procedure.
 Before the procedure administer laxative, suppository, or drug
to cleanse the bowel until the colon is clear of stool evening
before procedure.
 Keep the patient NPO for 8 hour before test.
 Teach the patient about being given barium by enema.
 Explain that cramping and urge to defecate may occur during
procedure and patient may be placed in various positions on
tilt table.

20.  The patient will be positioned on an examination table.
 A rectal tube will be inserted into the rectum to allow the
barium to flow into the intestine.
 During the procedure, the fluoroscope and examination table
will move and the patient may be asked to change positions.
 After the procedure give fluids, laxatives, or suppositories to
assist in expelling barium.
 Observe stool for passage of contrast medium.
 Tell patient that stool may be white for up to 72 hr.

21. Ultrasound
 Ultrasound is a noninvasive procedure used to assess the organs
and structures within the abdomen.
 It uses high frequency ultrasound waves that moves through the
body to the organs and structures within by a transducer. The sound
waves bounce off the organs like an echo and return to the
transducer. The transducer processes the reflected waves, which
are then converted by a computer into an image of the organs or
tissues being examined.
 An ultrasound gel is placed on the transducer and the skin to allow
for smooth movement of the transducer over the skin and to
eliminate air between the skin and the transducer for the best sound

22.  Used to show size and confiuration of an
organ
 It is the diagnostic procedure of choice for
detecting cholelithiasis (gallstones).
 Ultrasound is also used for detecting
appendicitis, acute cholecystitis, and other
changes in abdominal organs.

23. Different types of ultrasound scans
Abdominal ultrasound :
Study detects abdominal
masses(tumors and
cysts) and is also used
to assess ascites.
Hepatobiliary ultrasound
: Study detects
subphrenic abscesses,
cysts, tumors and
cirrhosis and is used to
visualize biliary ducts.
Gallbladder ultrasound :
Study detects gallstones
(high degree of
accuracy) and can be
used for a patient with
jaundice or allergic
reaction to GB contrast
media.

25. Different types of ultrasound
scans
Endosco
pic
ultrasoun
d
(EUS)
 Small ultrasound transducer is installed
on the tip of endoscope.
 Because EUS transducer gets closer to
the organ(s) being examined, images
obtained are more accurate and detailed
than those provided by traditional
ultrasound.
 Detects and stages esophageal, gastric,
biliary and pancreatic tumors and
abnormalities.

26. Different types of ultrasound
scans
Ultrasound
elastiograph
y.
(Fibroscan)
 Transient elastiography uses an
ultrasound transducer to assess level
of liver fibrosis.
 Used to monitor patients with chronic
liver disease.
 Nursing responsibility
 Explain the need to lie in dorsal
decurbitus position with right arm in
extreme abduction.

27. Nursing responsibility in ultrasound
 Instruct the patient to be NPO 8-12 hour
before ultrasound.
 Air or gas can reduce quality of images.
 Food intake can cause gallbladder contraction,
resulting in suboptimal study.

28. Computed tomography
 Noninvasive radiologic examination combines
special x-ray machine used for CT (exposures
of different depths) with computer.
 Study detects mainly biliary tract, liver, and
pancreatic disorders.
 Use of contrast medium accentuates density of
differences and helps detect biliary problems.

30. Nursing responsibility
 Explain procedure to the patient
 Determine sensitivity to iodine if contrast
medium is used.

31. Magnetic Resonance Imaging
(MRI)
 Noninvasive procedure using radiofrequency
waves and magnetic field.
 IV contrast medium (gadolinium) may be used.
 Procedure is used to detect hepatobiliary disease,
hepatic lesions, and sources of GI bleeding and to
stage colorectal and other cancer.
 Contraindicated in patients with metal implants
(eg : pacemaker)or who is pregnant.

33. Nursing responsibility
 Explain procedure to the patient.
 Check for pregnancy, allergies, and renal function.
 Rave patient remove all metal objects.
 Ask about any surgical insertion of staples, plates, dental brides, or
other metal appliances.
 Remove metallic foil patches.
 Assess for claustrophobia and and the need for antianxiety
medication.
 Keep patient NPO for 6 hour before procedure.
 Keep the patient still during the procedure

34. Cholangiography
 Cholangiography is the imaging of the bile duct by
x-rays and an injection of contrast medium.
 There are mainly three types of cholangiography,
which are the :
o Percutaneous transhepatic cholangiography
o Surgical cholangiography
o Magnetic resonance Cholangio-pancreatography

35. Percutaneous transhepatic
cholangiography (PTC)
 Under local anesthesia and monitored
Anastasia care, a long needle is passed into
liver (under fluoroscopy) and into bile duct.
 Bile is removed and radiopaque contrast
medium is directly injected into biliary system.
 Used to determine filling of hepatic and biliary
ducts.

37. Nursing responsibility
 Assess patient’s medications for
contraindications, precautions or complications
with use of contrast medium.
 Keep patient NPO for 8-12 hour before test.
 Start prophylactic IV antibiotic 1 hour prior.
 After the procedure, Observe patient for signs of
hemorrhage, bile leakage, and infection.
 Observe safety precautions until sedation wears
off.
 Maintain bed rest for 6h.

38. Surgical cholangiography
 Contrast medium is injected into bile duct during
surgery on biliary structures.
 Nursing responsibility
 Explain that anesthesia will be used.
 Assess patient’s medication for contraindications,
precautions or complications with the use of contrast
medium.

39. Magnetic resonance Cholangio-
pancreatography
 Non-invasive study uses of MRI technology to obtain images of
biliary and pancreatic duct.
 Nursing responsibility
 Explain procedure to the patient.
 Check for pregnancy, allergies, and renal function.
 Rave patient remove all metal objects.
 Ask about any surgical insertion of staples, plates, dental brides, or other metal
appliances.
 Remove metallic foil patches.
 Assess for claustrophobia and the need for anti-anxiety medication.
 Keep patient NPO for 6 hour before procedure.
 Keep the patient still during the procedure

40. Nuclear imaging scans
(scintigraphy)
 Shows size, shape, and position of organ.
 Functional disorders and structural defects
may be identified.
 Radionuclide (radioactive isotope) is injected
IV, and a counter (scanning) device picks up
radioactive emission, which is recorded on
paper.
 Only tracer doses of radioactive isotopes are

41. Nursing responsibility
 Tell patient that substance to be ingested
contains only traces of radioactivity and poses
little, to no danger.
 Schedule no more than one radionuclide test
on the same day.
 Explain to patient need to lie flat during
scanning.

42.  In general we can classify nuclear imaging
scans ( scintigraphy) in to three :
 Gastric emptying studies
 Hepatobiliary scintigraphy (HIDA)
 Scintigraphy of GI bleeding

43. Gastric emptying studies
 Used to assess ability of stomach to empty solids.
 Cooked egg containing Tc-99m and toast are
eaten with water.
 Images are obtained at 0, 1, 2, and 4 hr later.
 Study is used in patients with gastric emptying
disorders caused by peptic ulcer, ulcer surgery,
diabetes, gastric malignancies, cancer or
functional disorders

45. Hepatobiliary scintigraphy (HIDA)
 Patient is given IV injection of Tc-99m and
positioned under camera to record distribution
of tracer dose in liver, biliary tree, gallbladder,
and proximal small intestine.
 Used to identify obstructions of bile ducts (e.g.,
gallstones, tumors), diseases of gallbladder,
and bile leaks.

46. Scintigraphy of GI bleeding
 Tc-99m labeled sulfur colloid or Tc-99m
labeling of the patient’s own red blood cells
(RBCs) to determine the site of active GI blood
loss.
 Sulfur colloid or the patient’s RBCs are
injected, and images of the abdomen are
obtained at intermittent intervals.

48. Defecography
 Uses fluoroscopy or MRI to assess the shape and position of
the rectum during defecation.
 Using a lubricated small plastic tip, Fill rectum and anus with
barium.
 Oral barium allows small bowel to be visualized.
 The person then sits on a toilet-like seat attached to the X-ray
table and is asked to push and empty the rectum.
 Images are taken while person is sitting at rest, straining,
squeezing and during defecation.
 Detects pelvic floor abnormalities.

49.  Nursing responsibility
 Keep patient NPO for 2h
 2 enemas are given 2h before, 15 min apart.
 Oral barium is given 1h before

51. Gastric Emptying Breath Test
(GEBT)
 Non invasive test that measures CO2 in a patient’s
breath
 Used to diagnosis delayed gastric emptying.
 Baseline breath test done.
 Then patient eats a special test meal that include a
scrambled egg mix and spirulina plantensis, a protein
enriched with carbon-13 .
 It is measured in breath samples collected at multiple
time points after the meal.

52.  Nursing responsibility
 Teach patient to be NPO after midnight and that
the test takes 4h.
 Can be done in any clinical setting.
 Does not require special training or special
precautions related to radiation

54. Virtual colonoscopy
 Combines CT scanning or MRI with computer virtual
reality software to detect intestine and colon diseases,
including polyps, colorectal cancer, diverticulosis, and
lower GI bleeding.
 Air is introduced via a tube placed in rectum to
enlarge colon to enhance visualization.
 Images obtained while patient is on back and
abdomen.
 Computer combines images to form 2- and 3-D
pictures that are viewed on monitor.

55.  It produce images of the colon and the rectum.
 The test is less invasive than a conventional colonoscopy but does
require radiation and prior cleansing of the colon.
 Virtual colonoscopy enables one to better see inside a colon that is
narrowed due to inflammation or a growth.
 However, if a polyp is discovered using virtual colonoscopy, a
conventional colonoscopy will then be needed to obtain a biopsy or
remove it.
 A disadvantage of virtual colonoscopy is that it may be less
sensitive in obtaining information on the details and color of the
mucosa. In addition, it is less sensitive in detecting small (less than
10 mm) or flat polyps.

56.  Nursing responsibility
 Bowel preparation similar to colonoscopy.
 Unlike conventional colonoscopy, no sedatives
are needed and no scope is used. Procedure
takes about 15-20 min.

58. Diagnostic studies
Radiologic studies
Endoscopic studies
Blood chemistries
Liver biopsy
Fecal tests
Liver function tests

59. ENDOSCOPY
 Endoscopy refers to the direct visualization of a body structure
through endoscope.
 Endoscope is a lighted fiberoptic instrument with camera attached
allowing the ability to take video and still capture pictures.
 Some endoscopes contains a channel through which to pass
instruments, such as biopsy forceps and cytology brushes.
 The GI structures that can be examined by endoscopy include the
esophagus, the stomach, the duodenum, and the colon.
 The pancreatic, hepatic, and common bile ducts can be visualized
with an endoscope. This procedure is called endoscopic retrograde
cholangiopancreatography (ERCP).

60.  Endoscopy is often done in combination with biopsy and
cytologic studies and invasive and therapeutic procedures.
 Examples include polypectomy, sclerosis or banding of
varices, laser treatment, cauterization of bleeding sites,
papillotomy, common bile duct stone removal, and balloon
dilation.
 The major complication of GI endoscopy is perforation
through the structure being scoped.
 All endoscopic procedures require informed, written consent.
 Many endoscopic procedures require IV short-acting
sedation.

61. Endoscopic studies
Colonoscopy
Endoscopic retrograde cholangiopancreatography
(ERCP)
Esophagogastroduodenoscopy (EGD)
Laparoscopy (peritoneoscopy)
Sigmoidoscopy
Video capsule endoscopy (VCE)
Endoscopic ultrasound

62. Colonoscopy
 Directly visualizes entire colon up to ileocecal valve
with flexible fiberoptic scope.
 Patient’s position is changed frequently during
procedure to assist with advancement of scope to
cecum.
 Used to diagnose or detect inflammatory bowel
disease, polyps, tumors, and diverticulosis and dilate
strictures.
 Procedure allows for biopsy and removal of polyps
without laparotomy.

63.  Nursing responsibility
 Before procedure:
 Bowel preparation is done. This varies depending on physician.
For example, patients may be kept on clear liquids 1-2 days
before procedure. Cathartic and/or enema given the night before.
 An alternative is to give 1 gal of polyethylene glycol (GoLYTELY,
Colyte) evening before (8-oz glass q10min) or Prepopik, one
packet the night before colonoscopy and a second packet
morning of colonoscopy.
 Explain to patient that flexible scope will be inserted while patient
in side-lying position.
 Explain to patient that sedation will be given.

64.  After procedure:
 Patient may experience abdominal cramps caused by stimulation
of peristalsis because the bowel is constantly inflated with air
during procedure.
 Observe for rectal bleeding and manifestations of perforation
(e.g., malaise, abdominal distention, tenesmus).
 Check vital signs

66. Endoscopic retrograde cholangiopancreatography
(ERCP)
 Fiberoptic endoscope (using fluoroscopy) is orally inserted
into descending duodenum, then common bile and pancreatic
ducts are cannulated.
 The pancreatic, hepatic, and common bile ducts can be
visualized with an endoscope
 Contrast medium is injected into ducts and allows for direct
visualization of structures.
 Technique can also be used to retrieve a gallstone from distal
common bile duct, dilate strictures, biopsy, diagnose
pseudocysts.

67.  Nursing responsibility
 Before procedure:
 Explain procedure to patient, including patient role.
 Keep patient NPO 8 hr before procedure.
 Ensure consent form signed.
 Administer sedation immediately before and during procedure.
 Administer antibiotics if ordered.
 After procedure:
 Check vital signs.
 Check for signs of perforation or infection.
 Be aware that pancreatitis is most common complication.
 Check for return of gag reflex.

69. Esophagogastroduodenoscopy
(EGD)
 Directly visualizes mucosal lining of esophagus,
stomach, and duodenum with flexible endoscope.
 Test may use video imaging to visualize stomach
motility.
 Inflammations, ulcerations, tumors, varices, or
Mallory-Weiss tears may be detected.
 Biopsies may be taken and varices can be treated
with band ligation or sclerotherapy

70.  Nursing responsibility
 Before procedure:
 Keep patient NPO for 8 hr.
 Make sure signed consent is on chart.
 Give preoperative medication if ordered.
 Explain to patient that local anesthesia may be sprayed on throat before insertion
of scope and that patient will be sedated during the procedure.
 After procedure:
 Keep patient NPO until gag reflex returns.
 Gently tickle back of throat to determine reflex.
 Use warm saline gargles for relief of sore throat.
 Check temperature q15-30min for 1-2 hr (sudden temperature spike is sign of
perforation)

72. Laparoscopy (peritoneoscopy)
 Peritoneal cavity and contents are visualized with
laparoscope.
 Biopsy specimen may also be taken.
 Done with patient in operating room.
 Double-puncture peritoneoscopy permits better
visualization of abdominal cavity, especially liver.
 Can eliminate need for exploratory laparotomy in
many patients.

73.  Nursing responsibility
 Make sure signed consent is on chart.
 Keep patient NPO 8 hr before study.
 Administer preoperative sedative medication.
 Ensure that bladder and bowels are emptied.
 Observe for possible complications of bleeding
and bowel perforation after the procedure.

75. Sigmoidoscopy
 Directly visualizes rectum and sigmoid colon
with lighted flexible endoscope.
 Sometimes special table is used to tilt patient
into knee-chest position.
 Used to detect tumors, polyps, inflammatory
and infectious diseases, fissures,
hemorrhoids.

76.  Nursing responsibility
 Administer enemas evening before and morning of
procedure.
 Patient may have clear liquids day before, or no dietary
restrictions may be necessary.
 Explain to patient knee-chest position (unless patient is
older or very ill), need to take deep breaths during insertion
of scope, and possible urge to defecate as scope is
passed.
 Encourage patient to relax and let abdomen go limp.
 Observe for rectal bleeding after polypectomy or biopsy

78. Video capsule endoscopy
(VCE)
 Patient swallows a capsule with camera (approximately the size of a
large vitamin), which provides endoscopic visualization of GI tract .
 Most commonly used to visualize small intestine and diagnose
diseases such as Crohn’s disease, small bowel tumors, small bowel
injury due to NSAIDs, celiac disease, and malabsorption syndrome
and to identify sources of possible GI bleeding in areas not
accessible by upper endoscopy or colonoscopy.
 Camera takes >50,000 images during 8-hr examination.
 Capsule relays images to monitoring device that patient wears on
belt.
 After examination, images are downloaded to a workstation.
 Its sensitivity in detecting the source of GI bleeding, small lesions,
esophageal varices, colonic polyps, and colorectal cancer is under

79.  Nursing responsibility
 Instruct patient to fast overnight.
 Patient may have bowel preparation similar to colonoscopy.
 The video capsule is swallowed, and clear liquids resumed after 2 hr and
food and medications after 4 hr.
 Procedure is comfortable for most patients.
 Eight hours after swallowing the capsule, the patient returns to have the
monitoring device removed.
 A patency capsule may be used first in patients determined to be high risk
for capsule retention due to strictures.
 Peristalsis causes passage of the disposable capsule with a bowel
movement.

81. Endoscopic ultrasound
 Combined use of endoscopy and ultrasound
using an ultrasound transducer attached to an
endoscope.
 Enables visualization of esophagus, stomach,
intestine, liver, pancreas, and gallstones.
 Similar to EGD.

82. Diagnostic studies
Radiologic studies
Endoscopic studies
Blood chemistries
Liver biopsy
Fecal tests
Liver function tests

83. Blood chemistries
Study Description and purpose Nursing responsibility
Amylase •Measures secretion of amylase by
pancreas.
•Is important in diagnosing acute
pancreatitis.
•Level of amylase peaks in 24 hr and
then drops to normal in 48-72 hr.
•Depending on method, reference
interval is 30-122 U/L (0.51-2.07 μkat/L).
•Obtain blood sample in acute attack of
pancreatitis.
Explain procedure to
patient.

84. Study Description and
purpose
Nursing responsibility
Lipase Measures secretion of
lipase by pancreas.
Level stays
elevated longer than
serum amylase in acute
pancreatitis.
Reference interval: 31-
186 U/L (0.5-3.2 μkat/L).
Explain procedure to
patient.

85. Study Description and
purpose
Nursing responsibility
Gastrin Gastrin is a hormone
secreted by cells of the
antrum of
the stomach, the
duodenum, and the
pancreatic islets
of Langerhans.
Reference interval: 25-
100 pg/mL when fasting
Explain procedure to
patient.

86. Liver Biopsy
 The purpose of a liver biopsy is to obtain hepatic
tissue that can be used in establishing a diagnosis
or assessing fibrosis.
 It may also be useful for following the progress of
liver disease, such as chronic hepatitis.
 The patient lies supine with the right arm over the
head.
 Instruct the patient to expire fully and to not

87.  The two types of liver biopsy are open and closed.
 The open method involves making an incision and removing
a wedge of tissue. It is done in the operating room with the
patient under general anesthesia, often concurrently with
another surgical procedure.
 The closed, or needle, biopsy is a percutaneous procedure in
which the site is infiltrated with a local anesthetic and a
needle is inserted between the sixth and seventh or eighth
and ninth intercostal spaces on the right side. Often done
using ultrasound or CT guidance.
 Needle used for the test are,

88.  Nursing responsibility
 Before procedure:
 Check patient’s coagulation status (prothrombin time,
clotting or bleeding time).
 Ensure that patient’s blood is typed and crossmatched.
 Take vital signs as baseline data.
 Explain holding of breath after expiration when needle is
inserted.
 Ensure that informed consent has been signed.

89.  After procedure:
 Check vital signs to detect internal bleeding q15min ×
2, q30min × 4, q1hr × 4.
 Keep patient lying on right side for minimum of 2 hr to
splint puncture site.
 Keep patient in bed in flat position for 12-14 hr.
 Assess patient for complications such as bile
peritonitis, shock, pneumothorax.

90. Fecal Tests
Fecal analysis
 Form, consistency, and color are noted.
 Specimen examined for mucus, blood, pus, parasites, and fat content.
 Tests for occult blood (guaiac test, Hemoccult, Hemoccult II, Hemoccult-SENSA,
Hematest) are done.
 Single DNA test (PreGen-Plus) is a panel of DNA markers used to detect and
monitor colorectal cancer.
 Nursing responsibility
 Observe patient’s stools.
 Collect stool specimens.
 Check stools for blood.
 Keep diet free of red meat for 24-48 hr before occult blood test.

91. Stool culture
 Tests for the presence of bacteria, including
Clostridium difficile.
 Nursing responsibility
 Collect stool specimen.

92. Liver Function Studies
 Liver function tests (LFTs) are laboratory
(blood) studies that reflect hepatic disease.

93. Test Reference interval Description and Purpose
Serum
bilirubin
Measurement of liver’s ability to
conjugate and excrete bilirubin, allowing
differentiation between unconjugated
(indirect) and conjugated (direct) bilirubin
in plasma.
• Total Reference interval:
0.3-1.0 mg/dL (5.1-17
μmol/L)
Measurement of direct and indirect total
bilirubin.
• Direct Reference interval:
0.1-0.3 mg/dL (1.7-5.1
μmol/L)
Measurement of conjugated bilirubin.
Elevated in obstructive jaundice.
• Indirect Reference interval:
0.2-0.8 mg/dL (3.4-12
μmol/L)
Measurement of unconjugated bilirubin.
Elevated in hepatocellular and hemolytic
conditions.
Urinary
bilirubin
Reference interval: 0
or negative
Measurement of urinary excretion of
conjugated bilirubin.

94. Test Reference interval Description and Purpose
Protein Metabolism
Protein (serum) • Albumin, reference interval:
3.5-5.0 g/dL (35-50 g/L)
• Globulin, reference interval:
2.3-3.4 g/dL (23-34 g/L)
• Total protein, reference interval:
6.4-8.3 g/dL (64-83 g/L)
• A/G ratio, reference interval:
1.5:1-2.5:1
Measurement of serum proteins
manufactured
by the liver.
α-Fetoprotein Reference interval: <10 ng/mL
(<10 mcg/L)
Indication of hepatocellular
cancer.
Ammonia Reference interval: 10-80 mcg
N/dL (6-47 μmol N/L)
Conversion of ammonia to urea
normally occurs in the liver.
Increase can result in hepatic
encephalopathy secondary to
liver cirrhosis.

95. Test Reference interval Description and Purpose
Hemostatic Function
Prothrombin time
(PT)
Reference interval: 11-12.5
sec
Determination of
prothrombin activity.
International
normalized ratio
(INR)
Reference interval: In
general, 2-3 is the desired
therapeutic level with warfarin
(Coumadin), depending on
laboratory
Standardized system of
reporting PT based on
a reference calibration
model and calculated
by comparing the
patient’s PT with a
control value.
Vitamin K Reference interval: 0.1-2.2
ng/mL
(0.22-4.88 nmol/L)
Essential cofactor for
many clotting factors.

96. Test Reference interval Description and Purpose
Serum Enzymes
Alkaline
phosphatase
(ALP)
Reference interval: 38-126
U/L (0.65-2.14 μkat/L),
depending on method and
age
Originates from bone and liver.
Serum levels rise when excretion is
impaired as a result of obstruction
in the biliary tract.
Aspartate
Aminotransferase
(AST)
Reference interval: 10-30
U/L (0.17-0.51 μkat/L)
Elevated in liver damage and
inflammation.
Alanine
Aminotransferase
(ALT)
Reference interval: 10-40
U/L (0.17-0.68 μkat/L)
Elevated in liver damage and
inflammation.
γ-Glutamyl
transpeptidase (GGT)
Reference interval: 0-30
U/L (0-0.5 μkat/L)
Present in biliary tract (not in
skeletal or cardiac muscle).
Increase in hepatitis and alcoholic
liver disease. More sensitive for
liver dysfunction than ALP.

97. Test Reference interval Description and Purpose
Lipid Metabolism
Cholesterol
(serum)
Reference interval: <200
mg/dL (<5.2 mmol/L),
varying with age
Synthesis and excretion
by liver. Increase in
biliary obstruction.
Decrease in cirrhosis and
malnutrition.

98. References
• Lewis’s Medical Surgical Nursing
Assessment and Management of Clinical
problems, fourth south Asia edition
• Brunner & Suddarth’s Textbook of
Medical-Surgical Nursing 10th edition
• Wikipedia/ Google