General Diagnostics


General Diagnostics


ERCP

Endoscopic retrograde cholangiopancreatography (ERCP) is a procedure used to identify stones, tumors, or narrowing in the bile ducts. The procedure is done through an endoscope.

Description
An intravenous (IV) line is placed in your arm. You will lie on your stomach or on your left side for the test. Medicines to relax or sedate you will be given through the IV. Sometimes a spray to numb the throat is also used. A mouth guard will be placed in your mouth to protect your teeth. Dentures must be removed. After the sedative takes effect, the endoscope is inserted through the mouth. It is passed through the esophagus (food pipe) and stomach until it reaches the duodenum (the part of the small intestine that is closest to the stomach).

You should not feel any discomfort and may have little or no memory of the test. You may gag as the tube is passed down your esophagus. As the scope is in place, there will be some stretching of the stomach and duodenum. You may feel stretching of the ducts.

A thin tube (catheter) is passed through the endoscope and inserted into the tubes (ducts) that lead to the pancreas and gallbladder. A special dye is injected into these ducts, and x-rays are taken. This helps the doctor see stones, tumors, and any areas that have become narrowed.

Special instruments can be placed through the endoscope and into the ducts.

Why the Procedure is Performed
The procedure is used mostly to treat any problems of the pancreas or bile ducts that can cause abdominal pain(usually in the right upper or middle stomach area) and yellowing of the skin and eyes (jaundice).

ERCP may be used to:

  • Open the entry of the ducts into the bowel (sphincterotomy)
  • Stretch out narrow segments (bile duct strictures)
  • Remove or crush gallstones
  • Take tissue samples to diagnose a:
  • Tumor of the pancreas, bile ducts, or gallbladder
  • Conditions called biliary cirrhosis or sclerosing cholangitis
  • Drain blocked areas

Note: Imaging tests generally will be done to diagnose the cause of symptoms before an ERCP is done. These include ultrasound tests, CT scan, or MRI scan.

Risks
Reactions to the anesthesia, dye, or drug used during this procedure may include:

  • Blurred vision
  • Breathing problems
  • Dry mouth
  • Feeling of burning or flushing
  • Hives
  • Low blood pressure or slow heart rate
  • Nausea
  • Throat spasm
  • Problems emptying your bladder (urine retention)

Risks from the procedure include:

  • Bleeding
  • Hole (perforation) of the bowel
  • Inflammation of the pancreas (pancreatitis), which can be very serious

Before the Procedure
You will need to fast for at least 4 hours before the test and sign a consent form. Remove all jewelry so that it will not interfere with the x-ray.

Tell your doctor if you have allergies to iodine or you have had reactions to other dyes used to take x-rays.

You will need to arrange a ride home for after the procedure.

After the Procedure
Someone will need to drive you home from the hospital.

The air that is used to inflate the stomach and bowel during an ERCP can cause some bloating or gas for about 24 hours. After the procedure, you may have a sore throat for the first day, which may last for up to 3 – 4 days.

Stick to light activity on the first day after the procedure. Avoid heavy lifting for the first 48 hours.

You can treat pain with acetaminophen (Tylenol). Do not take aspirin, ibuprofen, or naproxen. Putting a heating pad on your belly may relieve pain and bloating.

The doctor or nurse will tell you what to eat. Most often, you will want to drink fluids and eat only a light meal on the day after the procedure.

Call your health care provider if you have:

  • Abdominal pain or severe bloating
  • Bleeding from the rectum or black stools
  • Fever above 100 degrees F (37.8 degrees C)
  • Nausea or vomiting

Alternative Names
Endoscopic retrograde cholangiopancreatography; Papillotomy; Endoscopic sphincterotomy; ERCP

References
Kimmey, MB. Complications of gastrointestinal endoscopy. In: Feldman M, Friedman LS, Brandt LJ, eds.Sleisenger & Fordtran’s Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 40.,Medline Plus.

Colonoscopy

A colonoscopy is an exam that views the inside of the colon (large intestine) and rectum, using a tool called a colonoscope.

The colonoscope has a small camera attached to a flexible tube that can reach the length of the colon.

How the Test is Performed
You will usually be given medicine into a vein to help you relax. You should not feel any discomfort. You will be awake during the test and may even be able to speak, but you probably will not remember anything.

You will lie on your left side with your knees drawn up toward your chest. The colonoscope is inserted through the anus. It is gently moved into the beginning of the large bowel and slowly advanced as far as the lowest part of the small intestine.

Air will be inserted through the scope to provide a better view. Suction may be used to remove fluid or stool.

The health care provider gets a better view as the colonoscope is moved back out. Therefore, a more careful exam is done while the scope is being pulled back. The doctor may take tissue samples with tiny biopsyforceps inserted through the scope. Polyps may be removed with snares, and images may be taken.

Specialized procedures, such as laser therapy, may also be done.

How to Prepare for the Test
You will need to completely cleanse your intestines. A problem in your large intestine that needs to be treated may be missed if your intestines are not cleaned out.

Your health care provider give you the steps for cleansing your intestines. This may include using enemas, not eating solid foods for 2 or 3 days before the test, and taking laxatives.

You will be asked to drink plenty of clear liquids for 1 – 3 days before the test. Examples of clear liquids are:

  • Clean coffee or tea
  • Fat-free bouillon or broth
  • Gelatin
  • Sports drinks
  • Strained fruit juices
  • Water

You will usually be told to stop taking aspirin, ibuprofen, naproxen, or other blood-thinning medicines for several days before the test. Keep taking your other medicines unless your doctor tells you otherwise.

You will need to stop taking iron pills or liquids a few days before the test, unless your health care provider tells you it is okay to continue. Iron can make your stool dark black, which makes it harder for the doctor to view inside your bowel.

How the Test Will Feel
The medicines will make you sleepy so that may not feel any discomfort or have any memory of the test.

You may feel pressure as the scope moves inside. You may feel brief cramping and gas pains as air is inserted or the scope advances. Passing gas is necessary and should be expected.

You may have mild abdominal cramping and pass a lot of gas after the exam.

Why the Test is Performed
Colonoscopy may be done for the following reasons:

  • Abdominal pain, changes in bowel movements, or weight loss
  • Abnormal changes (such as polyps) found on sigmoidoscopy or x-ray tests (CT scan or barium enema)
  • Anemia due to low iron (usually when no other cause has been found)
  • Blood in the stool, or black, tarry stools
  • Follow-up of a past finding, such as polyps or colon cancer
  • Inflammatory bowel disease (ulcerative colitis and Crohn’s disease)
  • Screening for colorectal cancer

Normal Results
Normal findings are healthy intestinal tissues.

What Abnormal Results Mean
Abnormal pouches on the lining of the intestines, called diverticulosis
Areas of bleeding
Cancer in the colon or rectum
Colitis (a swollen and inflamed intestine) due to Crohn’s disease, ulcerative colitis, infection, or lack of blood flow
Small growths called polyps on the lining of your colon (which can be removed through the colonoscope during the exam)
Risks

  • Heavy or ongoing bleeding from biopsy or removal of polyps
  • Hole or tear in the wall of the colon that requires surgery to repair
  • Infection needing antibiotic therapy (very rare)
  • Reaction to the medicine you take to relax, causing breathing problems or low blood pressure

Considerations
After the test, you will feel sleepy for a period of time. You may have a headache or feel sick to your stomach or bloated, but this is not common. You may pass a lot of gas.

You should be able to go home about 1 hour after the test. You must plan to have someone take you home after the test, because you will be woozy and unable to drive. The nurses and doctors will not let you leave until someone arrives to help you.

When you are home:

Drink plenty of liquids. Eat a healthy meal to restore your energy.You should be able to return to your regular activities the next day.Avoid driving, operating machinery, drinking alcohol, and making legal decisions for at least 24 hours after the test.
References
Kimmey MB. Complications of gastrointestinal endoscopy. In: Feldman M, Friedman LS, Brandt LJ, eds.Sleisenger and Fordtran’s Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier;2010:chap 40.

Pasricha PJ. Gastrointestinal endoscopy. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 136.

Endoscopy

Endoscopy is a way of looking inside the body using a flexible tube that has a small camera on the end of it. This instrument is called an endoscope.

How the Test is Performed
There are many types of endoscopes. Each one is named according to the organs or areas they are used to examine.

For example:

  • Arthroscope: Used to look directly in the joints
  • Bronchoscope: Used to look in the airways and lungs
  • Cystoscope: Used to view the inside of the bladder
  • Laparoscope: Used to look directly at the ovaries, appendix, or other abdominal organs

An endoscope is passed through a natural body opening or small cut. For example, a laparoscope is inserted through small surgical cuts in the pelvic or belly area. In men, a urinary tract endoscope is passed through the opening of the urethra.

A gastrointestinal endoscope may be inserted through the mouth or anus. An ultrasound probe can be added to a gastrointestinal endoscope. This is called an endoscopic ultrasound. Depending on the area of interest, this device can also be passed through the mouth or anus.

Small instruments can be inserted through an endoscope and used to take samples of suspicious tissues.

This article offers a general overview on endoscopy. For more information, see the specific procedure:

  • Anoscopy
  • Bronchoscopy
  • Colonoscopy
  • Cystoscopy
  • EGD (esophagogastroduodenoscopy)
  • Enteroscopy
  • Endoscopic retrograde cholangiopancreatography (ERCP)
  • Laparoscopy
  • Sigmoidoscopy

How to Prepare for the Test
Ask your health care provider if you need to do anything to prepare for your endoscopy. You may be asked not to eat or drink before most types of endoscopy. Before an examination of the lower gastrointestinal tract, you may be asked to use enemas or laxatives to clear out the large intestine.

How the Test Will Feel
You may be given medicine to help you relax and possibly fall asleep. This is called sedation. With the right sedation, you should have little, if any, discomfort.

Sedation is usually not given to people having an endoscopic ultrasound of the rectum. The endoscope will make you feel like you need to move the bowels (pass stool), but it should not cause any pain.

Why the Test is Performed
There are many different reasons to perform an endoscopy. For example, your doctor may order an endoscope if you have bleeding, pain, difficulty swallowing, and a change in bowel habits. Colonoscopy can also be done to screen for colon polyps and colon cancer.

For more information, see the specific article:

Anoscopy
Bronchoscopy
Colonoscopy
Cystoscopy
Esophagogastroduodenoscopy (EGD)
Enteroscopy
Endoscopic retrograde cholangiopancreatography (ERCP)
Laparoscopy
Sigmoidoscopy

Normal Results
The endoscopy should show normal appearance and function of the area being examined.

What Abnormal Results Mean
Abnormal results depend on the type of exam being performed. Your health care provider will explain your results after the endoscopy.

For detailed information see:

Anoscopy
Bronchoscopy
Chorionic villus sampling
Colonoscopy
Cystoscopy
Esophagogastroduodenoscopy (EGD)
Enteroscopy
Endoscopic retrograde cholangiopancreatography (ERCP)
Laparoscopy
Sigmoidoscopy

Risks

  • Bleeding
  • Infection
  • Pain
  • Tearing (perforation) of the tissue wall during endoscopy
  • Reactions to the sedation can occur, although they are rare. For this reason your breathing, blood pressure, heart rate, and oxygen level will be monitored during the procedure.

Considerations
Endoscopies also can be used to treat certain diseases or conditions. For example, tumors can be removed or bleeding from lesions can be stopped.

Update Date: 2/20/2011
Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Medline plus

Pulmonary Function Test

Pulmonary function tests are a group of tests that measure how well the lungs take in and release air and how well they move gases such as oxygen from the atmosphere into the body’s circulation.

How the Test is Performed
Spirometry measures airflow. By measuring how much air you exhale, and how quickly, spirometry can evaluate a broad range of lung diseases. In a spirometry test, while you are sitting, you breathe into a mouthpiece that is connected to an instrument called a spirometer. The spirometer records the amount and the rate of air that you breathe in and out over a period of time.

For some of the test measurements, you can breathe normally and quietly. Other tests require forced inhalation or exhalation after a deep breath. Sometimes you will be asked to inhale the substance or a medicine to see how it changes your test results.

Lung volume measurement can be done in two ways:

The most accurate way is to sit in a sealed, clear box that looks like a telephone booth (body plethysmograph) while breathing in and out into a mouthpiece. Changes in pressure inside the box help determine the lung volume. Lung volume can also be measured when you breathe nitrogen or helium gas through a tube for a certain period of time. The concentration of the gas in a chamber attached to the tube is measured to estimate the lung volume.
To measure diffusion capacity, you breathe a harmless gas, called a tracer gas, for a very short time, often for only one breath. The concentration of the gas in the air you breathe out is measured. The difference in the amount of gas inhaled and exhaled measures how effectively gas travels from the lungs into the blood. This test allows the doctor to estimate how well the lungs move oxygen from the air into the bloodstream.

How to Prepare for the Test
Do not eat a heavy meal before the test. Do not smoke for 4 – 6 hours before the test. You’ll get specific instructions if you need to stop using bronchodilators or inhaler medications. You may have to breathe in medication before or during the test.

How the Test Will Feel
Since the test involves some forced breathing and rapid breathing, you may have some temporary shortness of breath or lightheadedness. You breathe through a tight-fitting mouthpiece, and you’ll have nose clips.

Why the Test is Performed
Pulmonary function tests are done to:

  • Diagnose certain types of lung disease (such as asthma, bronchitis, and emphysema)
  • Find the cause of shortness of breath
  • Measure whether exposure to chemicals at work affects lung function
  • Check lung function before someone has surgery

It also can be done to:

  • Assess the effect of medication
  • Measure progress in disease treatment

Normal Results
Normal values are based upon your age, height, ethnicity, and sex. Normal results are expressed as a percentage. A value is usually considered abnormal if it is less than 80% of your predicted value. Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

Different measurements that may be found on your report after spirometry include:

  • Expiratory reserve volume (ERV)
  • Forced vital capacity (FVC)
  • Forced expiratory volume (FEV)
  • Forced expiratory flow 25% to 75%
  • Functional residual capacity (FRC)
  • Maximum voluntary ventilation (MVV)
  • Residual volume (RV)
  • Peak expiratory flow (PEF).
  • Slow vital capacity (SVC)
  • Total lung capacity (TLC)

What Abnormal Results Mean
Abnormal results usually mean that you may have some chest or lung disease. Some lung diseases (such as emphysema, asthma, chronic bronchitis, and infections) can make the lungs contain too much air and take longer to empty. These lung diseases are called obstructive lung disorders. Other lung diseases make the lungs scarred and smaller so that they contain too little air and are poor at transferring oxygen into the blood. Examples of these types of illnesses include:

  • Extreme overweight
  • Fibrosis of the lungs
  • Lung cancer
  • Sarcoidosis and scleroderma

Risks
The risk is minimal for most people. There is a small risk of collapsed lung in people with a certain type of lung disease. The test should not be given to a person who has experienced a recent heart attack, or who has certain other types of heart disease.

Considerations
Your cooperation while performing the test is crucial in order to get accurate results. A poor seal around the mouthpiece of the spirometer can give poor results that can’t be interpreted. Do not smoke before the test.

Alternative Names
PFTs; Spirometry; Spirogram; Lung function tests

References
Hegewald MJ, Crapo RO. Pulmonary function testing. In: Mason RJ, Broaddus VC, Martin TR, et al, eds. Murray and Nadel’s Textbook of Respiratory Medicine. 5th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 24.

Reynolds HY. Respiratory structure and function: mechanisms and testing. In: Goldman L, Schafer AI, eds.Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 85.

Update Date: 12/12/2011
Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Denis Hadjiliadis, MD, Assistant Professor of Medicine, Division of Pulmonary, Allergy and Critical Care, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.