GI Flashcards
(235 cards)
1
Q
What is a KUB?
A
Kidneys, ureters, and bladder
2
Q
What are the indications for a KUB?
A
Assessing the urogenital tract and specifically looking for calcifications
3
Q
What is the technique for a KUB?
A
AP supine
4
Q
What does a KUB look like?
A
There is a stone either in the lower pole of the right kidney or the ureter. The little right thing is abnormal.
5
Q
What are the plain films w/o contrast?
A
- Acute abdominal series (2-3 views). With this, we will get pictures of the abdomen, but we will also get a CXR
- If patient can stand → AP supine, PA upright, and PA chest
-If patient is unable to stand → AP supine, left lateral decubitus, AP supine chest
-If patient is unable to stand and turn → AP supine, AP supine chest, cross table view (lateral)
- KUB- does not necessarily show the diaphragm
6
Q
What are the indications for an acute abdominal series?
A
Assessing the entirety of the GI tract and specifically looking at gas patterns and areas of possible obstruction
7
Q
What is the technique for an acute abdominal series?
A
If patient can stand → AP supine, PA upright, and PA chest
If patient is unable to stand → AP supine, left lateral decubitus, AP supine chest
If patient is unable to stand and turn → AP supine, AP supine chest, cross table view (lateral)
8
Q
What does the position look like for an acute abdominal series?
A
9
Q
What does AP Supine look like on acute abdominal series look like on x-ray?
A
AP Supine showing some dilated bowel loops. Look for gas
10
Q
What are the indications for an acute abdominal series x-ray?
A
Good way to see gas in the stomach and the intestines
11
Q
What does AP upright look like on acute abdominal series look like on x-ray?
A
AP Upright. Looking for gas in places that it should or shouldn’t be. An obstruction could be seen if an area looks normal up until a point and then it turns black.
12
Q
What does PA chest look like on acute abdominal series look like on x-ray?
A
PA chest is useful for looking for abnormalities just under the diaphragm, sometimes we can see the stomach bubble extended above the diaphragm and sometimes we can see hiatal hernias like this as well.
13
Q
What are the indications for an Upper GI Series with contrast?
A
Concern for mechanical esophageal stricture. Upper abdominal pain with a possible gastric or duodenal origin. Surgical procedure gastric or duodenal procedure. Patient receives something to drink (typically chalky) while x-ray images are being taken.
14
Q
What is the technique for an Upper GI Series with contrast?
A
Barium contrast is typically used and we should use water soluble contrast if concerned for perforation. The location of area of concern typically dictates images obtained
15
Q
What does an Upper GI series look like on imaging with contrast?
A
16
Q
What is the issue in this image
A
Stomach polyp in the right image before it exits into the small intestine. The contrast is white in this image and the polyp or mass did not take up any of the contrast
17
Q
What is the issue in this image
A
This is a sagittal view and we can see the white contrast in the esophagus. The esophagus in this image looks fairly normal. Peristalsis can look kind of bumpy like that.
18
Q
What is the issue in this image
A
The image is a barium swallow. The patient had issues swallowing and a weird sensation when the liquid would attempt to pass the diaphragm. The contrast and liquid will go down and then towards the end, it will suddenly come back up
19
Q
What are the indications for an Upper GI series with contrast?
A
Further evaluation of: strictures, obstruction, masses, abnormal motility
Limitations: mild strictures and small masses
20
Q
What is the technique for an upper GI series with contrast?
A
Can be obtained with or w/o UGI
Images taken every 15-30 minutes until contrast reaches terminal ileum
Normally takes 30-120 minutes
21
Q
What does an Upper GI Series w/ Small Bowel follow-through look like on Imaging?
A
See the movement of contrast. In the 6 image series, the contrast is given via an NG tube and you can tell it is a pediatric patient. We can see the movement of contrast throughout the GI system
22
Q
What are the indications for a lower GI series?
A
Colonic stricture (position and length), colonic fistula, colonic bladder fistula, colonic uterus fistula, postoperative leak after surgery
23
Q
What is the technique for a lower GI series?
A
A rectal tube or barium enema is inserted, and contrast is given.
Multiple images can be obtained to view all areas of the large intestine from the ileocecal valve to the rectum
24
Q
What does a normal lower GI series w/ contrast look like on imaging?
A
25
What are the structures of the lower GI?
Small intestine jejunum and ileum which is distal to the ligament of Treitz
Large intestine
26
How do you assess intraluminal air?
Normal:
- Locations: stomach, small intestine, large intestine
- Appearance: diffuse, irregular pattern
Abnormal:
- Appearance: distended bowels, air fluid levels
27
What is this pathology?
Intraluminal air. This image shows dilated bowel loops. They are wider than they should be. Things that cause this is an obstruction, ileus
28
How do you assess extraluminal air?
Rarely normal to have
Exception shortly after abdominal surgery
more consistent with a hole or perforation
29
What is this pathology?
upright. air will rise, fluid will settle. Faint black line shows abnormal air under the diaphragm on the right side above the liver. This shows signs of a perforation or something that is leaking air into the abdominal cavity.
30
What is this pathology?
Supine. space in between walls of the intestine and that is a sign of perforation or air that is leaking into the abdominal cavity that shouldn't be there. There is a slight separating of the walls of the colon
31
What is this pathology?
Left lateral decubitus. seeing separation of the liver from the diaphragm, so there is air under the diaphragm.
32
What is this pathology?
Upright/Erect: multiple air/fluid levels on erect film. Bubble type appearance in image , there are clear bubble of air with liquid and this is called our air fluid levels. Probably not seen on supine films, but in other positions you can probably tell. Top buble in image is probably a stomach bubble.
33
What is this pathology?
Supine: multiple dilated gas filled loops of small bowel throughout the abdomen. We will not see air fluid levels, because our imaging is not lok across the air fluid levels. The bowel looks much more dilated and bigger. The diameter across the colon is larger than it should be so it is called a dilated bowel loop.
34
What is this pathology?
L lateral decubitus: multiple air fluid level c/w obstruction. shows air fluid levels.
35
What do normal bowels look like on imaging?
1. Small Bowel
Located centrally within the abdomen
Folds running across the diameter of the lumen
Usually contains small volume air
2. Large Bowel
Located peripherally
Folds run part way across the diameter of the lumen (haustral folds)
Usually contains some air or fecal matter
36
What is the rule of 3-6-9?
Small bowel- 3 cm
Large bowel- 6 cm
Cecum- 9 cm
37
What are the organs and soft tissues we should be looking at on abdominal imaging?
Liver, spleen, stomach, kidneys, psoas muscles, bladder
38
What GI devices should we be looking for in our external structures and artifacts step in assessing imaging?
Nasogastric Tube (NG Tube), Dobhoff tube (Feeding Tube), Percutaneous gastrostomy tube (PEG Tube), gastric pacemaker, colostomy bag appliances
39
What GI devices should we be looking for in our external structures and artifacts step in assessing imaging?
Ureteral stent, foley catheter, suprapubic catheter, Nephrostomy tubes, Contraceptive devices (IUDs), Tubal ligation devices, penile implants, brachytherapy seeds
40
What post op devices should we be looking for in our external structures and artifacts step in assessing imaging?
Surgical staples, surgical drains, surgical sponges, embolization coils, IVC filters, Vascular grafts
41
What miscellaneous devices should we be looking for in our external structures and artifacts step in assessing imaging?
Foreign bodies, contrast material, patient restraint devices, vertebroplasty/kyphoplasty cement, hernia mesh, clothing, pannus
42
What is the pathology?
Sternotomy wires
43
What is the pathology?
insulin pump and IUD
44
What does the “Dense Stuff” look like on imaging?
Bones: ribs, vertebrae, pelvis, femur
Calcifications: stones, phleboliths, and vascular structures
45
What is the pathology?
kidney stone in the right ureter
46
What is the pathology?
gallstones collect in sac like structure
47
What is the pathology?
phleboliths that are benign.
48
What is the pathology?
look at where the aorta bifurcates into the iliac artery and there is significant calcification. Probably has very bad cardiovascular disease
49
What is the pathology?
pathology in the RUQ has a well defined bubble with an outer edge and the white outer edge, lets us know that there are calcifications there and makes it appear like there is an aortic aneurysm and there is calcification from that
50
What is the pathology?
normal EGD
51
What is an EGD?
Esophagogastroduodenoscopy, where an endoscope is inserted into the upper GI tract for direct visualization. THIS IS THE BEST way to evaluate the esophagus.
52
What are the diagnostic indications for an EGD?
Chronic upper abdominal pain, dysphagia, iron deficiency anemia, chronic GERD, persistent vomiting/diarrhea, unexplained weight loss, hematemesis, surveillance/monitoring
53
What are the therapeutic indications for an EGD?
Foreign body removal, dilation or stenting of strictures, esophageal variceal ligation (putting a clamp on the structure so that it doesn’t rupture), Upper GI bleeding control, placement of feeding tube, management of achalasia
54
What are the absolute contraindications to an EGD?
Perforated bowel, peritonitis (infection of the abdominal cavity), toxic megacolon (risk for aspiration and regurgitation)
55
What are the relative contraindications to an EGD?
1. Coagulation issues
- Severe thrombocytopenia
- Coagulopathy
2. Increased risk of perforation
- Connective tissue disorders
- Recent GI or neck surgeries
3. Unstable patient
56
What are the complications of an EGD?
These are rare and occur in less than 2% of patients
1. Sedation- most common complication
- Hypoxemia
- Hypotension
- Arrhythmias
- Aspiration
2. Procedural
- Bleeding
- Infection
- Perforation
57
What is the pathology?
With Barret’s, we can see that transition zone between tissue types (it should all be the same type of tissue) on imaging and this one has a mass with it, making it even more likely to develop esophageal cancer
58
What is the pathology?
Esophagitis, this would be something like reflex causing this or GERD, doesn’t necessarily have to be continuous and can be more kind of patchy. The white areas are more inflamed but so are the red areas. Should be pinkish
59
What is the pathology?
Varices are related to liver disease. Enlarged blood vessels that have dilated and can’t constrict in the ways that they normally would or should. This enlarged linear blood vessels, but them very easy to nic and start a bleed
60
What is the pathology?
Gastric mass this image is most likely taken at the top of the stomach, we can tell because the black portion at the top is actually the scope itself, so they inserted the scope and they do a retroflex view to views masses at the opening of the esophagus and stomach
61
What is the pathology?
Gastric ulcer, may have a bleed at one point, or maybe it hasn’t bleed yet, but there are some telangiectasisas surrounding it so it may have.
62
What is the pathology?
The bleeding ulcer is blocking the view of the entire esophagus, so they would go in and cauterize this and this can be really scary to do. Or if they are concerned they could do a biopsy to confirm bacteria or malignancy
63
What is an EUS?
Endoscopic US. It is a US attachment placed on the end of an endoscope. It can be used to evaluate masses/lesions within the wall of the esophagus. It can also be used to assess other organs of the Upper GI tract as well as surrounding tissues
64
What is the pathology?
Bottom right corner is an EGD where you can’t tell if it is masses or varices. The CT confirms and shows masses and varices around the esophagus
65
What are the functional studies for the esophagus?
Modified Barium Swallow, FEES, Manometry, pH monitoring
66
How is a modified barium swallow (MBS) study performed?
Fluoroscopy evaluates swallowing and peristalsis w/the use of barium-containing liquids/solids. Thin liquid and then a thicker liquid and then a solid like eggs or something. Done with different consistencies and with a speech therapist at the bedside.
67
What are the indications for an MBS?
Dysphagia and suspected aspiration
68
What are the contraindications of an MBS?
Perforation and GI obstruction
69
What are the complications of an MBS?
N/V, Hypersensitivity, Constipation/Diarrhea
70
What are the indications for a Manometry?
Dysphagia, odynophagia, GERD, Non-cardiac chest pain
71
What are the contraindications of Manometry?
Recent esophageal/nasal trauma or surgery
Significant epistaxis history
Esophageal varices
Coagulation issues
72
What are the complications of Manometry?
Vomiting, epistaxis, and perforation
73
How is an esophageal pH Monitoring study performed?
The probe is inserted through nares into the esophagus that contains pH sensors
74
How are manometry functional studies performed with regard to the stomach?
The probe is placed through the nares and guided endoscopically into the duodenum. Measurements were taken at rest and with a small meal. This tube may be placed/put in and kept there for up to 24 hours, so sometimes these are taped to patients faces and you may see them walking around with these.
75
What are the indications for manometry functional studies with regard to the stomach?
Gastric motility disorders, GERD, Non-cardiac chest pain
76
What are the contraindications for manometry functional studies with regard to the stomach?
Recent esophageal/nasal trauma or surgery, significant epistaxis history, esophageal varices, coagulation issues, perforation
77
What are the complications for manometry functional studies with regard to the stomach?
Vomiting, epistaxis, and perforation
78
What is this pathology?
Gastric outlet obstruction because gas, air, or food things cannot pass through the SI due various different reasons, but most commonly due to a mass or stricture. May also see some solid stuff in these patients towards the bottom from where nothing is passing through the SI. These patients present with a bloating sensation and N/V.
79
What is this pathology?
free air under the diaphragm due to perforation
80
What is this pathology?
Schatzki ring
81
What is this pathology?
Schatzki ring
82
What is a Schatzki ring?
Schatzki's ring is a thin, circular band of tissue that forms at the lower end of the esophagus, where it meets the stomach. Thought to be related to GERD
83
What ia hiatal hernia?
84
How is gastric emptying performed?
Nuclear medicine (NM) study where radionuclide tracer is mixed with food then images taken at set intervals to assess progression
85
What are the indications for gastric emptying?
Suspected gastroparesis (early satiety and post-prandial N/V or abdominal pain), suspected rapid gastric emptying, GERD
86
What are the contraindications for gastric emptying?
Allergy to recommended meal. Hyperglycemia in diabetics.
87
What are the complications of gastric emptying?
Allergic reaction to tracer. Discomfort/nausea associated w/ meal consumption
88
What does a gastric emptying study look like?
There are both anterior and posterior images, taken at different time intervals. The tracer is in the pattern of the stomach. By the end, we should be seeing the tracer towards the end of the system and it is not, so this is abnormal.
89
What are the general indications for H. pylori?
Gram-negative rod. Often acquired in childhood. Colonizes gastric epithelium. Associated w/ development of gastritis, ulcers, and gastric cancers.
Found in most patients with PUD
Infected individuals 10-20% chance if developing peptic ulcers and 1-2% chance of developing gastric cancer
> 70% of infected individuals are asymptomatic
90
What are the noninvasive interventions for H pylori?
Urea breath test
Stool antigen test
Serologic test
91
What are the invasive interventions for H pylori?
If the patient has an EGD, testing can be done on biopsy samples
CLO test aka rapid urease test (most common one ordered in clinical practice)
PCR detection of H. pylori DNA
Histological examination/staining
Culture
92
What is celiac disease?
Autoimmune disease causes chronic inflammation of the proximal small bowel
93
What is IgA anti-tissue transglutaminase?
High specificity for celiac disease, but up to 3% of people with cleiac disease have depleted IgA and have a false negative test. Total IgA is often measured as well, and if low, IgG anti-tissue transglutaminase antibodies can be measured.
94
What is the most definitive testing for celiac disease?
It is most accurate when a patient is on a diet contain gluten
95
If there is low suspicion of celiac disease, what kind of testing should we do?
Serologic test only
Anti-tissue transglutaminase Ab (tTG-IgA) or anti-endomysial Ab (ema)
If positive, biopsy is needed
96
If there is high suspicion of celiac disease, what kind of testing should we do?
Serologic test AND biopsy
97
What is this pathology?
Small bowel stricture or narrowing where the contrast is not passing through the way that it should at the red arrow. We should be able to see the loops of bowel, but instead we’re seeing some areas that the contrast is not reaching. This lets us know that something is going on, whether it is a masss pressing on it, adhesions form surgery, cervial surgery. The other part of the scarring is crossed over and pinching down on the external part of the intestine, but contrast still isnt passing through.
98
What is this pathology?
The SI is very dilated and are much wider than they should be. These are signs of an obstructive process.
99
What is this pathology?
We have dilated loops and superiorly we have some air fluid levels, where air is certainly rising above it. These are signs of an obstructive process
100
What is this pathology?
Obstruction of the LI on x ray. We can tell because of the dilated loops of bowel, very large and very wide, especially in this are of the transverse colon.
101
What is this pathology?
Appendicitis on CT Abd/pelvis
At the base of the LI where the cecum turns into the ileum, is where the appendix is and you can see in this image, it has a white ring around it, meaning it is more inflamed than normal. It is usually very hard to see an appendix on plain CT scan. Additionally, around the white line of inflamed tissue, we can also see some fat stranding of the surrounding tissues (very indicative of appendicitis).
102
What does a normal LI xray look like?
Mix of gas and stool material within the LI. We see some air along the side, which is normal for the LI, because it is still normal diameter.
103
What kind of contrast do we want to use if we are concerned for appendicitis?
Try to use IV contrast (inflammation will show up better)
If you can’t oral contrast should be fine, but the appendix shouldn’t light up, because it is so inflamed.
104
Why does fecal impaction occur?
Nervous system issues where patients have trouble excreting things the way that they should. This can also happen in patients who are extremely dehydrated and so things are hard for them to pass on their own. This requires digital dysimpaction
105
What is this pathology?
Fecal impaction on xray. Common cause of an obstructive pathway. We can see feces all the way through and especially in the rectum, which is typically where the impaction occurs. It is extremely uncommon for a patient to get an impaction in the ascending or transverse colon and for things NOT to get moved. It is MOST OFTEN in the rectum. Theintestines themselves look fairly normal as fas as diameters. There is obviously a mix of stool and gas.
106
What is an NM Tagged RBC scan?
Used with overt GI bleeds w/o obvious cause on endoscopy
Tagged RBC/GI bleed scan
Patients RBCs removed and tagged with radioactive nuclide
RBCs tranfused back into patient
Scans to detect radiation repeated every hour for 4 hours
Can help localize area to exam with traditional angiography
107
What does an NM Tagged RBC exam look like?
The image on top is considered normal. Then the photos on the bottom are taken at specific time intervals. The tracer lights up the aorta, but the bladder will show up dark as well, becuase the blood flows through the kidneys, so the kidneys will filter nuc med out. The abnormal portion is this dot on right side. This indicates an area of a leak, because they tracer it just staying and collecting in that one spot.
108
What is Fecal Occult testing?
FOBT for short or aka guaiac test which evaluates of there is blood in the stool
109
What causes blood in the stool?
Reflux esophagiits, peptic ulcer, gastritis, cancer, crohns, ulcerative colitis, diverticulitis, hemorrhoids
110
Why do we do stool cultures?
To screen for salmonella, shigella, campylobacterm and shiga toxin
Need separate order if looking for vibrio or Yersinia
111
Why do we order ova and parasites?
Microscopic exam
112
What is Lactoferrin?
It is sort of a nonspecific marker that lets us known there is some sort of inflammatory process going on
113
Why do we order Stool WBCs and Lactoferin?
WBCs in stool can be seen with: Salmonella, Shigella, Yersinis, Campylobacter, C. Diff, Enteroinvasive E. coli, Entamoeba histolyica, and IBD.
Lactoferrrin is a nonspecific marker of inflammation
Antigen detection for specific pathogen
114
What pathogens can cause infection in the GI tract?
E. coli, Salmonella, campylobacter, vibrio cholerae, shigells, clostriduim species, yersinis entercolitica, rotovirus, norovirus
115
What pathogens are caused by the ingestion of their toxins?
Staph aureus and clostridium botulinum
116
What pathogen causes Gastruc ulcer disease?
H. pylori
117
What pathogens can cause parasitic infection?
Entamoeba histolyica, giardia lamnlia, ascarias and friends, and enterobius vermicularis
118
What are the most common bacterial pathogens of the GI tract?
Shigella (dysentery)
Campylobacter
Vibrio
Yersinia
Staphylococcus
E. coli
Salmonella
Clostridium
119
What bacteria are more likely to cause bloody diarrhea?
Shigela, Campylobacter, Yersenia, E. coli, Salmonella
120
Define the Shigella pathogen
Produces shiga toxin. Exotoxin released by shigella and has toxic properties that disrupt protein synthesis in target cells. Shiga-lie toxins identified from other bacteria have similar effects. Always a pathogen. WATERY BLOODY diarrhea, fever, stomach spasms/pain - sx can last 7 days; abx- cipro or azithro
121
Define the Campylobacter pathogen
RAW CHICKEN Highly virulent sx: fever, rigors, myalgias, abd cramping, copious bloody diarrhea, sx can last 5-7 days, usually self-limiting, associated with Gullian-Barre syndrome, reactive arthritis, increased risk for IBD and colon cancer.
122
Define the Vibrio pathogen
Watery diarrhea, large volume - up to the patients body weight in liquid stools excreted in 12 hours, “rice water” stools vibriosis-often from other vibrio sp-watery diarrhea, fever, abd cramping, vomiting, often from raw/undercooked seafood, V. vulnificus= wound infection
123
Define the staphylococcus pathogen
Toxins are not destroyed by cooking, sx= sudden onset nausea, vomiting, diarrhea, abd cramps 1-8 hours after eating/drinking item with Staph toxin; generally < 24 hours
123
Define the Yersina pathogen
Enterocolitica, gram neg coccobacilli, fever abd pain, bloody diarrhea, often from raw/undercooked pork
124
What does it mean to be Enterotoxigenic (ETEC)?
Traveler’s diarrhea froma contaminated water source. Produce toxins that stimulate intestinal cells to secrete water into lumen of intestine, causing diarrhea
124
What are the sx of Enterotoxigenic (ETEC)?
Abdominal cramping, watery diarrhea, no vomiting or fever
125
What does it mean to be Enterohemorrhagic (EHEC)?
Known as E. coli with a code. Coming from food, unpasteruized milk, and cider
Siga like toxin that is cytotoxic to cells and microvilli of LI and can lead to damage to submucosa and bleeding; toxin triggers platelet activation and clot formation in vessels which leads to microangiopathic hemolysis and the clot burden can lead to kidney damage, so HUS
126
What are the sx of Enterohemorrhagic (EHEC)?
Watery diarrhea progressing to bloody diarrhea, abdominal cramping, no vomiting or fever.
126
What is Enterohemorrhagic (EHEC) associated with?
Hemorrhagic colitis and HUS
DO NOT GIVE ABX
127
What is always a pathogen and never a normal flora?
Salmonella, it is a flagellated organism
128
What are the sx of salmonella enteriditis?
Diarrhea (may be bloody), fever/chills, abd pain, WBCs in stool
129
What is salmonella enteriditis?
Most common food borne illness in developing countries. Known as “food poisoning”
Can develop into sepsis, pneumonia, endocardiitis, eningitis
Healthy person recovers in 2 weeks
Treat with fluid and electrolyte replacement
Incubation is 12-48 horus and duration is 3 days
130
What is salmonella enterica?
Contaminated food from infected person. “Typhoid fever”, 1-3 weeks after exposure developed. No known animal source. Invades intestinal epithelial cells, then lynph nodes, then organs, harbored in gallbladder as in the carrier state
131
What is Clostridium perfingens?
Normal flora in the intestinal tract, but can cause diarrhea through ingestion of bacteria contaminated food held at unsafe temperature. Can cause gas gangrene where sx include diarrhea, abd pain, NO VOMITING and last up to 24 hours
131
What are the sx of salmonella enterica?
HA, fever (usually high, then there is the rash), RLQ pain, splenomegaly, diarrhea (may be bloody)
132
What is Clostridium botulinum?
Causes botulism. Neurotoxin causes flaccid muscle paralysis, infant botulism from ingestion of spores. “Floppy baby syndrome” incubation: 18-36 hours and duration can be weeks or months.
132
What is C diff?
Causes antibiotic associated colitis. Normal inhabitant in intestine, proliferates after abx therapy, some strains. Profuse water diarrhea, distinctive odor, often with fever, causes include medications like clindamyacin and cephalosporins.
133
What is a big thing we say that kids should not have before 2?
Honey, because it can cause botulism
134
How can we test for C diff?
It is toxin induced so we can measure the A and B toxins with the C diff toxin assay
Reflex testing
C diff antigen detection cannot differentiate between the two
134
What is the treatment for C diff?
ORAL vanc, fidaxomicin, fecal transplant
May cause pseudomembrane colitis
135
What is teh leading cause of hospital acquired infections?
C diff
136
What are the two types of C diff?
Toxigenic
Non-toxigenic
137
What are the diagnostic steps to diagnosing C diff?
138
What is rotavirus?
Most common cause of viral diarrhea in infants and children. Incubation 1-4 days. Acute onset diarrhea and possibly some vomiting.
139
What is the diagnostic test for rotavirus?
We can test for antigen in the stool.
140
What is norovirus?
Often causes outbreaks in schools, cruise ships and jails. Lasts 1-3 days. Acute N/V/D often with fever and abdominal pain.
141
What is the diagnostic test for norovirus?
PCR testing available though often diagnosed clinically
142
What are the parasitic pathogens?
Protozoans and Nematodes that usually both present with eosinophilia
143
What are the protozoans?
Entamoeba histolytica, Giardia lamblia, and Cryptosporidium
144
What are the Nematodes?
Ascaris lumbricoides, Necator americanus, enterobius vermicularis
145
What is Entamoeba histolytica?
Invade mucous membranes of LI, multiply in mucosal crypts
146
What is Giardia?
Most common reported parasite in the US
Inhabits the SI
Can be asymptomatic or produce mile to severe sx- can lead to steatorrhea
No eosinophilia on CBC
147
What is cryptosporidium?
Causes diarrhea and abdominal pain
Common infection in AIDS patients
Diarrhea can last > 4 weeks
148
What is the testing for protozoan pathogens?
Stool for ova and parasites, PCR, stool antigen testing for giardia
149
What is Ascaris lumbricoides?
Aka round worm. It is the largest intestinal nematode parasite that infects humans
150
What is Necator americanus?
Aka hookworm. Found in southern US along coastal areas. Larvae penetrates skin and migrates to lungs and then to intestines, where they attach to wall of SI and ingest blood to cause anemia
151
What is Strongyoloides?
Aka threadworms is more common in some asian countries. Larvae infect through the skin and migrate through the lungs and cause an asthma like reaction. Eosinophilia as well.
152
What is Enterobius vermicularis?
Aka pinworms. The eggs are ingested by humans. Sx associated with migration of gravid female out from the anus to lay eggs on the perianal region at night. Causes severe perianal itching, loss of sleep, irritability, etc. Detected by “scotch tape prep”
153
What is the testing we cna do for nematodes?
Stool microscopy (ova and parasites)
Direct visualization by colonoscopy, scotch tape
PCR
CBC-eosinophilia
154
What are the GI tumor markers?
CEA (carcinoembryonic antigen), C19-9, AFP (alpha fetoprotein)
155
What is the CEA (carcinoembryonic antigen) tumor marker?
Elevated in most cancers, especially colorectal. Can be elevated in any colorectal disease, such as ulcerative colitis or diverticulitis. Also more elevated in smokers than non-smokers
156
What is the AFP (Alpha fetoprotein) tumor marker?
Elevated in many cancers, but especially liver or testicular/ovarian
156
What is the C19-9 tumor marker?
Associated more with accessory GI organ cancers. Can be elevated in gastric or colorectal cancer. Can be elevated in any biliary tress disorder, such as primary sclerosing cholangitis or chronic cholecystitis
157
What is a Magnetic Resonance Cholangiopancreatography (MRCP)?
Used to evaluate common bile duct abnormalities
Diagnostically equivalent to ERCP
Most useful in patients who can’t undergo ERCP
Screening test of choice of primary sclerosing cholangitis
Useful in evaluation of bile leak after surgery should be stapled off after surgery, but if they staples come loose, this is how we check)
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What is an example of a normal MRCP?
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What is the pathology on this MRCP?
Choledocholithiasis, aka gallstone blocking up the common bile duct. When something like this happens we have to be able to proceed with surgery or doing an ERCP
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What is an Endoscopic retrograde Cholangiopancreatography (ERCP)?
Both diagnostic and therapeutic. Makes sure all the structures are open and operating.
Inserted through the mouth and threaded down through the esophagus, stomach, and gallbladder
Combination endoscopy and contrast imaging
Can also be used to: obtain biopsy (can do brushings and sampling), retrieve stones, perform sphincterotomy, stent placement
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What is shown in this ERCP?
Contrast just stops injected into the biliary tree
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What is a percutaneous transhepatic Cholangiography (PTC)?
Needle is inserted through the skin, liver, and into the bile duct
It is used to evaluate common bile duct abnormalities
Diagnotically equivalent ot ERCP (but more risk of complications)
Most useful in patients who can’t undergo ERCP and MRCP is inconclusive
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What is a HIDA scan used to evaluate?
Acute and chronic cholecystitis, bile leak, biliary obstruction, sphincter of Oddi dysfunction
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What does a HIDA scan look like?
Tracer that is taken up by the gallbladder and then a medication is taken that reduces contraction of gallbladder and we measure the ejection fraction. This HIDA is an abnormal study. When the calogen is given, the contrast should be starting to leave the gallbladder slowly, but in this study it isn’t
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What is the normal bilirubin pathway?
Unconjugated bilirubin is water-insoluble and toxic to body cells, especially neurons. Made from breakdown of heme molecules. Bound to albumin in the blood. It is not excreted in the urine.
It is conjugated in the hepatocytes by combining it with glucuronic acid to make more water-solbule, and therefore easier for the body to excrete it.
Conjugated bilirubin secreted into the SI in bile. In the colon, bacteria convert conjugated bilirubin into urobilinogen and stercobiliogen which are then converted into urobilirubin and stercobilirubin.
Some urobilinogen absorbed from intestine into blood. Some is filtered out by the kidneys into urine, some is filtered by liver back into bile. Some urobilinogen turned into urobilin and stercobilin in the colon and excrted in the feces
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What are the blood tests of the bilirubin pathway?
Total bilirubin, unconjuagted bilirubin (indirect), and conjugated bilirubin (direct)
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What are the stool tests of the bilirubin pathway?
Urobilin, stercobilin
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What are the urine tests of the bilirubin pathway?
Urobilinogen and bilirubin (conjugated) would show up on a UA and key us in that something is going on in the bilirubin pathway.
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How is conjugated bilirubin filtered?
It is filtered into the urine, but alsmost all is reabsorbed at the proximal tubule. Therefore, bilirubin level in the urin is usually undetectable.
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What is jaundice?
Buildup of bilirubin in the blood causes exces bilirubin to be deposited into the skin and mucous membranes. Deposits in the sclera of the eyes first and then in the mucosal membranes, then the skin.
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When things go wrong in the prehepatic portion of the liver, what happens?
Increase in Total bilirubin
Increased in indirect bilirubin
Decrease in direct bilirubin WNL
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What are the 3 mechanisms of increased bilirubin?
Prehepatic, hepatocellular, post-hepatic
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What disorders are associated with prehepatic dysfunction?
Hemolysis disorders and some rare disorders of metabolism like Gilvert syndrome (doesn’t typically cause the same jaundice appearance) and Crigler-Najjar. We would see increased conjugated bilirubin in the gut and thus increased urobilingogen urine and feces. Trauma and HUS
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When things go wrong in the hepatocellular portion of the liver, what happens?
The hepatocytes are NOT WORKING
Increase in total bilirubin
Increased in indirect bilirubin
Increase in direct bilirubin (not really significant, but because some are still working, as the hepatocytes swell in relation to insult
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What are some of the causes associated with hepatocellular dysfunction?
Viral hepatitis, drugs, alcohol hepatitis
Indirect up d/t hepatocyte dysfunction
Direct up d/t swollen hepatocytes decreased excretion
Decreased direct bilirubin in stool- pale stools, increased urobilinogen in urine, + bilirubin in urine
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What is the de Ritis ratio and how is it used to distinguish between the type sof hepatitis?
The de Rites ratio is AST/ ALT
- Acute viral hepatitis: AST and ALT VERY elevated, ALT>AST, ratio < 1
- Chronic hepatitis: AST and ALT elevated, AST> ALT, ratio 1to about 2
- Alcoholic hepatitis: AST>>ALT ratio > 2, GGT also elevated
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What is a table that explains Prehepatic, hepatocellular, post-hepatic?
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What does a de Ritis ratio graph look ike?
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What is Hep A?
Fecal-oral transmission
Responsible for 50% of viral hepatitis cases in the US
Virus is shed in feces beginning 7-10 days after exposure.
Sx develop 1-3 weeks after exposure
Usually mild and self limiting: does not develop into chronic hepatitis and can however cause fulminant hepatitis but is rare
Usually food bourne illnesses
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What are the Hep A nonspecific abnormalities labs?
Increased ALT and AST (Alk phos mildly elevated)
Increased serum bilirubin, positive bilirubin in urine
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What are the Hep A specific abnormalities labs?
HAV IgM antibodies (After infective stage)
Virus or antigen can be detected in stool 1-2 weeks before sx
Cell culture not used.
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Why do we not use viral antigens?
Peak levels occur before patient seeks medical attention
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What is Hep B?
Transmission: blood, sexual contact, mom-baby
Can turn chronic
Vaccine is available
More common in the US and most attempted to prevent
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What are the Hep B labs?
1. HBsAg: acute infection and/or chronic infection
2. HBsAB: past infection or vaccination
Core antibody
3. HBcAb (IgM): acute infection
4. HBcAB (IgG): past infection and/or chronic infection
5. HBV DNA: acute or chronic infection
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What are the Hep B labs in table form?
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What is Hep C?
Transmission: blood, sexual contact, mom-baby
Can turn chronic (70-80%): 20-30% develop fibrosis/chronic, can develop hepatocellular CA
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What are the Hep C screening labs?
Detects > 95% of patients
Does not distinguish between acute or chronic infection
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What are the Hep C diagnostic labs?
Diagnosis-HCV RNA
HCV RNA Qualitative
Yes or no
Assessment of response
HCV RNA Quantitative (Viral Load)
Assess response to therapy
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What are the goals of therapy for Hep C?
Sustained viral response to no detectable virus 6 months after anti-viral treatment
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What is a table table that summarizes the hepatitis disorders?
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What is autoimmune hepatitis?
Rare
Workup:
Rule out viral causes
Measures anti-smooth muscle antibody
Biopsy
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What is alcoholic hepatitis?
Usually occurs after months to years of heavy alcohol use for years
Clinical symptoms include jaundice, RUQ pain or fullness sensation, fever, anorexia
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What are the lab tests for alcoholic hepatitis?
Elevated total bilirubin, direct and indirect bilirubin
Elevated GGT
Moderately elevated aminotransferases (AST and ALT)
De Ritis ratio > 2, usually > 5
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How can non-alcoholic fatty liver disease (NAFLD, may also be called NASH or MASH) cause hepatitis?
Fat infiltrate the liver and is usually asymptomatic.
Labs= mildly elevated AST and ALT, De Ritis ratio usually < 1
Imaging: changes can be seen on US or MRI
Biopsy is confirmatory-GOLD
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Define chornic liver disease
Chronic inflammation of the liver that leads to fibrosis and formation of nodules in the liver tissue. Cirrhosis-severe and advanced fibrosis with loss of liver function
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What are some possible causes of chronic liver disease?
Viral hepatitis, alcoholic liver disease, nonalcoholic fatty liver diease, hemochromatosis, Wilson’s disease, a 1 antitrypsin deficiency, autoimmune hepatitis, CHF, medications, sarcoidosis, primary biliary cholangitis, primary sclerosing cholangitis
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Describe what a paracentesis is
It can be diagnostic or therapeutic and is a frequently large volume.
Labs for evaluation of cause:
- Serum ascites albumin gradient (SAAG)
SAAG >/=1.1 g/dL-indicative of portal hypertension- cirrhosis or CHF
SAAG < 1.1 g/dL no portal hypertension-malignancy or nephrotic syndrome
-Total protein- helps distinguish causes of SAAG >1.1 g/dL
>2.5 g/dL- CHF
< 2.5 g/dL-cirrhosis
-Gram stian and culture
-Cytology
-PMN (polymorphonucelar cells, WBC) > 250 cells/mm3
-Culture with ID and sensitivities
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What are some of the causes of ascites?
1. Portal hypertension: liver failure, cirrhosis, CHF
2. Hypoalbuminemia: Nephrotic syndrome and malnutrition/malabsorption
3. Malignanacies
4. Intraabdominal infections
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What is a SAAG?
The SAAG (Serum-Ascites Albumin Gradient) lab test measures the difference in albumin levels between a patient's blood serum and ascitic fluid (fluid in the abdominal cavity) to help determine the cause of ascites, especially if it's related to portal hypertension.
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What is ascites?
Fluid collection in the abdominal cavity
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What does ascites look like on US?
This is fluid, because it is not entirely dark and still has some grayish shade to it
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What does ascites look like on CT?
Will have protuberent stomach. The slight gray separatign the skin and liver indicates ascites. The patient will say that they feel full.
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How do we diagnose and therapeutically address ascites?
Paracetesis in the abdominal cavity
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What is cholelithiasis/choledocholithiasis?
With or without obstruction. Can be seen on moat imaging studies. Typically with increased bilirubin, ALP and GGT
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What is cholecystitis?
Inflammation/infection of gallbladder. Acute vs chronic. RUQ gallbladder US is test of choice. Possible elevation in total bilirubin, ALP, and GGT
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What is an amniocentesis?
Centessis of the amniotic sac
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What is the pathology on this MRCP?
Choledocholithiasis, aka gallstone blocking up the common bile duct. When something like this happens we have to be able to proceed with surgery or doing an ERCP
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What is acute cholangitis?
inflammation/infection of biliary tree. High mortality if untreated, Charcot’s triad. Labs: blood cultures, liver enzymes, CBC (elevated WBCs), =/- bile culture
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What can be seen on this US?
The gallbladder is otulined in the white and is the sac like structures, not as solid, towards the cystic duct, it appears that there is a gallstone or perhaps some biliary sludge (thin consistency)
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What does the pancreas look like on CT?
Pancreas looks like “an ear of corn”
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What is this pathology?
Pancreatitis
Indicative by fat stranding
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What is this pathology?
Pancreatic cancer. Mass is sitting in the pancreatic head
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What is this pathology?
Pancreatic pseudocysts
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What are we looking for on US of the pancreas?
Masses, dilatation of pancreatic duct or CBD, inflammation of pancreatitis
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What does the pancreas look like on US?
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What are the tests for pancreatitis?
1. Amylase-low specificity and sensitivity
Produced primarily by pancreas and salivary glands
Cleared by kidneys: can be elevated w/o necessarily indicating acute illness in severe CKD/ESRD
2. Lipase-better specificity and sensitivity than amylase
Primarily produced by pancreas
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How can we diagnose actue pancreatitis?
Amylase (but helpful for determining the stage or assessing the course)
Lipase (better for diagnosis, because it is more specific)
ALT > 150 units/L may suggest gallstone pancreatitis as cause in patients with acute pancreatitis
lipase/amylase ratio > 2 may help rule out alcoholic etiology of acute pancreatitis
Transabdominal US main benefit is identification of gallstones or dilation of common bile duct due to choledocholithiasis
CT may show necrosis of the pancreas in severe pancreatitis
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How can we diagnose chronic pancreatitis?
Serum amylase and lipase may be elevated during acute attacks, normal values do not exclude the diagnosis
Serum alkaline phosphatase and bilirubin may be elevated owing to compression of the bile duct
Excess fecal fat may be demonstrated on the stool (steatorrhea)
MRCP may show morphological changes in the pancreas
ERCP can be diagnostic and therapeutic- can show dilated ducts, intraductal stones, or strictures
Pancreatic function tests, one is called fecal elastase that is a marker for pancretic function in the stool. Another one is called a secretin test (rarely performed)
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What things can be assessed in duodenum diagnostics?
1. Structural issues
X-ray
CT abdomen
EGD
2. Labs: Gastrin (look for gastrinoma and may consider Zollinger-Ellison syndrome)
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How do you differentiate between acute and chronic pancreatitis?
To differentiate between acute and chronic pancreatitis, focus on the duration and nature of symptoms, with acute pancreatitis featuring a sudden onset of severe pain that resolves within days, while chronic pancreatitis involves persistent or recurrent pain and can lead to permanent pancreatic damage.
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What is gastrin?
The hormone that regulates acid secretion in the stomach, elevated gastrin levels tend to promote duodenal ulcers
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What is gastrinoma?
Rare cancer that secretes gastrin, causing distal duodenal ulcers/ multiple ulcers (Zollinger-Ellison syndrome)
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What types of malabsorption happen most often with SI issues?
1. Fat:
a. Qaulitative:
Sudan III Stain (determines if the fecal fat is there, yes or no): not widely available in US
b. Quantitative
Fecal Fat measurement
72 hour stool collection
Available routinely in only a few centers
2. Carbohydrates: Hydrogen breath test
3. Protein: Not widely available test
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What labs can help us determine liver function?
Albumin, PT/INR, total bilirubin (conjugated or direct, unconjugated or indirect), platelets, cholesterol, BUN, glucose, ammonia
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What are some separate tests that are commonly ordered to help diagnose liver issues?
GGT and ammonia
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What are some of thesigns and sx of hepatic encephalopathy ?
acute alteration of mental status with no other obvious cause and a known h/o severe chronic liver disease
AMS (severoty of ammonia elevation, does not directly correlate to the mental status), fatigue, weakness/coordination issues
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What are some of the diagnostics of hepatic encephalopathy?
acute alteration of mental status with no other obvious cause and a known h/o severe chronic liver disease
Rule out above causes, ammonia- not diagnostic, non-contrasted CT head (don’t want to miss a brain bleed or stroke)
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What is ammonia?
Urea cycle disruption in the liver leads to excess ammonia. Excess ammonia can cause hepatic encephalopathy
