GI procedures Flashcards
Nasogastric Intubation
Passage of a tube through the nares, esophagus and into the stomach
Indications: Evacuate blood Decompress Remove toxic substances Provide enteral feedings
Required equipment Nasogastric tube Lubricant Cup of water with a straw Tape Large syringe
Nasogastric intubation complications and contraindications
Complications Bleeding Aspiration Tracheal intubation Erosion of naris (Long term) Pharyngeal/nasal perforation
Contraindications Facial trauma Basilar skull fracture Bilateral nasal obstruction Recent nasal, pharyngeal, esophageal or gastric surgery Bleeding diathesis
Types of nasogastric tubes
The Levin tube is a one-lumen nasogastric tube. The Levin tube is usually made of PVC with several drainage holes near the gastric end of the tube. There are graduated markings on the lumen so that you can see how far you have inserted the tube into the patient.
The Salem-Sump tube is a two-lumen tube. It has a drainage lumen and a smaller secondary tube that is open to the atmosphere. The second lumen allows for continuous suction and prevents gastric mucosa from being aspirated into the tube.
Esophagogastroduodenoscopy (EGD)
Esophagogastroduodenoscopy (EGD) is a procedure during which a small flexible endoscope is introduced through the mouth (or with smaller caliber endoscopes, through the nose) and advanced through the pharynx, esophagus, stomach, and duodenum. EGD is used for both diagnostic procedures and therapeutic procedures.
Other instruments can be passed through the endoscope to perform additional procedures. For example, a biopsy can be done in which a small tissue specimen is obtained for microscopic analysis. A polyp or tumor can be removed using a thin wire snare and electrocautery.
EGD indications
Diagnostic evaluation for signs or symptoms suggestive of upper GI disease, e.g. dyspepsia, dysphagia, noncardiac chest pain, recurrent emesis
Surveillance for upper GI cancer in high-risk settings, e.g. Barrett’s esophagus, polyposis syndromes
Biopsy for known or suggested upper GI disease, e.g. malabsorption syndromes, neoplasms, infections
Therapeutic intervention e.g. retrieval of foreign bodies, control of hemorrhage, dilatation or stenting of stricture, excision of neoplasms, gastrostomy tube placement
egd contraindications
Absolute contraindications
Known or suspected perforation
Medically unstable patients
Obstruction
Relative contraindications: Anticoagulation Pharyngeal diverticulum Recent head or neck surgery Esophageal stricture
EGD complications
Bleeding Infection Perforation Vocal cord injury Pharyngeal irritation Cardiopulmonary problems ** Cardiopulmonary events make up 50% of all major complications; such events are usually caused by the medications used for conscious sedation.
The following increase the risk of esophagitis:
- Alcohol use
- Cigarette smoking
- Surgery or radiation to the chest (for example, treatment for lung cancer)
- Taking certain medications, i.e. tetracycline, doxycycline, vitamin C and aspirin
- Prolonged vomiting
- Persons with weakened immune systems due to HIV and certain medications (such as corticosteroids)
- Fungi or viruses
Barrett’s Esophagitis
Esophageal adaption from chronic acid reflux
- Columnar epithelium replaces the squamous epithelium of the esophagus
- Premalignant condition
- Malignant transformation is highest in Caucasian men greater than 50 with more than 5 years of symptoms
Esophageal Cancer
Squamous cell in the proximal and mid esophagus, adenocarcinoma in the distal esophagus
20-30 times higher rate of occurrence in China
Risk Factors
Smoking
Ethanol use
High fat/low protein diet
GERD/Barrett’s esophagitis
Most common sites of metastasis are lungs, pleura, liver, stomach, peritoneum, kidneys and the adrenal gland.
Gastric Ulcer
Usually caused by disruption of the gastric mucosal barrier:
- Helicobacter pylori infection
- NSAIDS/aspirin
- The most common site is the angular incisura, followed by the lesser curvature and the antrum.
Gastric Cancer
Risk Factors: H. pylori Salty and smoked foods Chronic gastritis Smoking Diet low in fruits and vegetables Blood type A
Once 2nd most common cancer in U.S., now 14th
Primarily adenocarcinoma
In Japan, it remains the most common type of cancer among men
In western countries, the most common sites of gastric cancer are the proximal lesser curvature, cardia, and GE junction
In Asia, distal locations in the stomach are more common
distinguishing factor: upper GI to lower GI
ligament of treitz
Sigmoidoscopy
Flexible sigmoidoscopy is a procedure where the rectum and the lower (sigmoid) colon is examined under direct visualization. The flexible sigmoidoscope is a flexible tube 60 cm long and about 1.25 cm in diameter. It is inserted through the anus and advanced slowly into the rectum and sigmoid colon.
Sigmoidoscopy indications
Colorectal cancer screening
Preoperative evaluation prior to anorectal surgery
Surveillance of previously diagnosed (treated or untreated) malignancy (or polyp with high-grade dysplasia) in the rectum or sigmoid colon
Local treatment of ailments such as radiation proctitis
Removal of rectal foreign bodies
To perform therapeutic procedures such as endoluminal stent placement for strictures, balloon dilation, or decompression with placement of a decompression tube
Hematochezia requiring hemostasis
Sigmoidoscopy contraindications
Absolute contraindications Bowel perforation Acute diverticulitis Active peritonitis Fulminant colitis Cardiopulmonary instability
Relative contraindications
Lack of informed consent (except in emergencies)
Lack of patient cooperation
Lack of good bowel preparation
Sigmoidoscopy complications
Pain
Bleeding
Perforation
Infection
Colonoscopy
The advantage of colonoscopy over flexible sigmoidoscopy is the ability to find and remove polyps in the parts of colon that are beyond the reach of the flexible sigmoidoscope.
The patient is mildly sedated, the endoscope is inserted through the anus and advanced gently around the bends of the colon. If a polyp is encountered, a thin wire snare is used to remove it. Electrocautery (electrical heat) is applied to painlessly control any bleeding. Other tests can be performed during colonoscopy, including biopsy.
Colonoscopy indications
Colorectal cancer screening in average-risk adults
Evaluation and removal of polyps
Current or previous bowel resection for colon cancer
Family history of cancer
Management of inflammatory bowel disease
Identification of acute bleeding sites
Decompression of colon
colonoscopy contraindications
Absolute contraindications
Fulminant colitis
Known or suspected perforation
During early post-colectomy time period
Relative contraindications
History of radiation therapy for abdominal or pelvic cancer
History of abdominal or pelvic malignancy
Extensive adhesions from prior abdominal surgery
Bleeding dyscrasias
Anticoagulant therapy
Colonoscopy complications
Bleeding Perforation Respiratory depression Cardiac arrythmias or ischemia Transient bacteremia Nausea/vomiting Ileus
Colonoscopy/Sigmoidoscopy Preparation
In order to obtain accurate results, the rectum and the lower colon must be completely clean of stool. In general, this requires the use of one or two enemas prior to the procedure and may also call for a laxative and some dietary modifications. Under special circumstances, such as the presence of significant diarrhea, the preparation may be waived.
Pedunculated Polyp
Pedunculated polyps are mushroom-like tissue growths that are attached to the surface of the mucous membrane by a long, thin stalk, or peduncle.
The development of pedunctulated polyps can be due to inherited or non inherited causes.
Sessile Polyp
Sessile polyps sit right on the surface of the mucous membrane and do not have a stalk.
- Sessile polyps are flat.
- Generally have more malignant potential.
Colon Cancer
Surface of the cancer is generally irregular and ulcerated.
-Malignant tumors often are partially or completely circumferential and if left untreated obstruct the lumen.
- Ulcerative Colitis
Patients generally have more pain, cramping and rectal bleeding
Diarrhea and fever are common
On colonoscopy, characterized by ulceration, bleeding, continuous involvement and pseudopolyps
Mucosa is more friable and bleeds more easily than Crohn’s
Risk of coplon cancer rises each decade after diagnosis
- Crohn’s Disease
Symptoms can occur at any point along the gastrointestinal tract
Symptoms are similar to ulcerative colitis but usually:
More cramping with diarrhea
Less bleeding
Symptoms wax and wane
On colonoscopy, characterized by inflammation, cobble-stone appearance and “skip” lesions
ulcerative colitis vs crohn’s disease
crohn's: discontinuous involvement cobblestoning aphthous ulcers deep, longitudinal serpiginous ulcers rectal sparing or segmental inflammation anal lesions ileocecal valve stenotic and ulcerated
ulcerative colitis: continuous involvement erosions/ microulcers loss of vascular pattern rectal involvement ileocecal valve patulous and free of ulceration
Virtual Colonoscopy (VC)
Medical imaging procedure which uses imaging and computers to produce two- and three-dimensional images of the colon from the rectum, all the way to the distal ileum.
The procedure is used to diagnose colon and bowel disease, including polyps, diverticulosis and cancer.
VC is performed via x-rays, i.e. computed tomography (CT) or magnetic resonance imaging (MRI).
Colorectal Cancer Screening Tests
FOBT Stool DNA Sigmoidoscopy Colonoscopy Colonography DCBE DRE
Fecal Occult Blood Test (FOBT)
Advantages:
No cleansing of the colon is necessary.
Samples can be collected at home.
The cost is low compared with other colorectal cancer screening tests.
FOBT does not cause bleeding or tearing/perforation of the lining of the colon.
Disadvantages:
This test fails to detect most polyps and some cancers.
False-positive results are common. Very sensitive but not specific since the wood resin of Guaiacum trees reacts with iron
Dietary restrictions and changes, such as avoiding meat, certain vegetables, vitamin C, iron supplements, and aspirin are often recommended for several days before a guaiac FOBT.
Should be repeated three to four times prior to drawing any conclusions
Additional procedures, such as colonoscopy, may be necessary if the test indicates an abnormality.
DNA Stool Testing
Cologuard
Came to market 2014, FDA approved
Recommended for screening in average-risk patients aged 50+, to repeat every three years
Colonoscopy may still be needed if test is abnormal
Does not require special bowel prep or change in diet or medication
Can be done at home
Does not require time off from work
Sigmoidoscopy- advantages and disadvantages
Advantages
The test is usually quick, with few complications.
For most patients, discomfort is minimal.
In some cases, the doctor may be able to perform a biopsy and remove polyps during the test, if necessary.
Less extensive cleansing of the colon is necessary with this test than for a colonoscopy.
Disadvantages
This test allows the doctor to view only the rectum and the lower part of the colon. Any polyps in the upper part of the colon will be missed.
There is a very small risk of bleeding or tearing/ perforation of the lining of the colon.
Additional procedures, such as colonoscopy, may be necessary if the test indicates an abnormality.
Colonoscopy
advantages and disadvantages
Advantages
This test allows the doctor to view the rectum and the entire colon.
The doctor can perform a biopsy and remove polyps or other abnormal tissue during the test, if necessary.
Disadvantages
This test may not detect all small polyps, nonpolypoid lesions, and cancers, but it is one of the most sensitive tests currently available.
Thorough cleansing of the colon is necessary before this test.
Some form of sedation is used in most cases.
Although uncommon, complications such as bleeding and/or tearing/perforation of the lining of the colon can occur.
Colonography
advantages and disadvantages
This test allows the doctor to view the rectum and the entire colon.
The test takes only 10-15 minutes and does not require the use of anesthesia.
This is not an invasive procedure, so there is little risk of bleeding or tearing/perforation of the lining of the colon.
Still covered on most insurances, recommended to be done every five years in average risk patients age 50+.
Disadvantages
This test may not detect all small polyps, nonpolypoid lesions, and cancers.
Thorough cleansing of the colon is necessary before the test.
If a polyp or non-polypoid lesion 6 to 9 millimeters in size or larger is detected, standard colonoscopy, usually immediately after the virtual procedure, will be recommended to remove the polyp or lesion or perform a biopsy.
During the procedure the rectum is insufflated with gas for visibility, the gas is removed at the end of the procedure but patients report this is extremely uncomfortable during the procedure and takes several days to fully resolve.
Double Contrast Barium Enema (DCBE)
advantage and disadvantages
Advantages
This test usually allows the doctor to view the rectum and the entire colon.
Complications are rare.
No sedation is necessary
This is still a covered screening benefit on most insurances at recommended intervals of five years.
Disadvantages
This test may not detect some small polyps and cancers.
Thorough cleansing of the colon is necessary before the test.
False-positive results are possible.
The doctor cannot perform a biopsy or remove polyps during the test.
Additional procedures are necessary if the test indicates an abnormality.
Digital Rectal Exam (DRE)
advantages and disadvantages
Disadvantages
The test can detect abnormalities only in the lower part of the rectum.
Additional procedures are necessary if the test indicates an abnormality.
