Chapter 6 Lab Tests & Clinical Procedures

1. Lipase Test = tests for the level of lipase in the blood. Lipase is an enzyme that digests fat.

2. Liver function test (LFTs) = tests for presence of enzymes and bilirubin in blood.

Examples of liver function tests are = ALT (Alanine Transaminase) and AST (Aspartate Transaminase), these enzymes are present in many tissues.

Serum = clear fluid that remains after blood has clotted

ALT and AST levels are elevated in the serum of patients with liver disease

Alkaline Phosphatase (ALK PHOS) = is another enzyme that may be elevated in patients with liver, bone and other diseases

Serum Bilirubin = another enzyme that has elevated levels in patients with liver disease and jaundice

Direct Bilirubin Test = measures conjugated bilirubin, high levels indicate liver disease or biliary obstruction

Indirect Bilirubin Test = measures unconjugated bilirubin, and elevated levels suggest hemolysis, and can occur in newborns

3. Stool Culture = tests for microorganisms in feces, feces are placed in a growth medium and examined microscopically.

4. Stool Guaiac Test or Hemoccult Test = test that detects occult, meaning hidden blood in feces. This is an important screening for colon cancer.

   Guaiac = is a chemical found in wood from trees, when added to a stool sample it will react with any blood present in feces

Clinical Procedures

X-RAY tests = are used in many ways to detect pathological conditions.

Contrast Medium = is used in many x-ray tests to enhance the ability to see in substances that x-rays cannot penetrate. Contrast mediums are used to visualize a specific area of the digestive system. The contrast, because of its increased density relative to body tissue allows organs and parts be distinguished from one another.

1. Lower Gastrointestinal Series (Barium Enema) = X-RAY images of the colon/rectum obtained after injection of barium into rectum.

Barium = is a contrast medium

2. Upper Gastrointestinal Series = XRAY images of the esophagus, stomach and small intestine, obtained after giving barium by mouth.

   Barium swallow = is the study of the esophagus.

3. Cholangiography = XRAY examination of the biliary system after injection of contrast into bile ducts.

   Endoscopic Retrograde Cholangiopancreatography (ERCP) = is a contrast medium given through an oral catheter and passes through esophagus, stomach, duodenum and into bile ducts to help diagnose problems with bile ducts, gallbladder and pancreas

   Magnetic Resonance Cholangiopancreatography (MRCP) = is a type of MRI scan, special contrast dye is injected intravenously during the scan and detailed pictures of the pancreas, gallbladder and bile ducts are taken.

4. Computed Tomography (CT) earlier known as CAT scan = series of XRAY’s are taken in multiple views, especially cross section.

   CT scan = uses circular array of XRAY beams to produce the cross-sectional image, based on differences in tissue densities.

   Tomography = produces a series of XRAY pictures showing multiple views of an organ

Ultrasound Exams

1. Abdominal Ultrasonography = sound wave beams into abdomen to produce an image of abdominal viscera. This is especially useful in exams of fluid filled structures like the gallbladder.

2. Endoscopic Ultrasonography (EUS) = use of an endoscope combined with ultrasound to examine organs in the gastrointestinal tract. Endoscope inserted through mouth or rectum and ultrasound images are taken.

Magnetic Resonance Imaging

Magnetic Resonance Imaging (MRI) = magnetic waves produce images of organs and tissues in all three planes of the body. Magnetic Resonance Imaging does not use XRAY’s instead it detects differences in tissue composition, water content and blood vessel density to show sites of trauma, infection or cancer.

Nuclear Medicine Test

HIDA Scan = radioactive imaging procedure that tracks the production and flow of bile from the liver and gallbladder to the intestines.

HIDA stands for Hepatobiliary Iminodiacetic Acid

Cholescintigraphy is another name for the HIDA scan and determines if the gallbladder is functioning properly

Other Procedures

1. Fecal Transplant = Transfer of stool from a healthy donor into the gastrointestinal tract of the patient.

   C difficile = is an infection of harmful bacteria that causes diarrhea and colitis

2. Bariatric Surgery = procedures used for weight loss in patients with severe obesity.

   One type of of bariatric surgery is bariatric sleeve gastrectomy which is the removal of a large portion of the stomach

   Another type is gastric bypass = reduces the size of the stomach to a volume of 2 tablespoons and bypasses much of the small intestine