CIS GI Case 2 Flashcards
What is in the differential for hematochezia: hemorrhoids, anal fissures, diverticulum bleed, IBD, infectious colitis, ischemic colitis
Hemorrhoids: painless bleeding is usually associated with bowel movement, coats stool at end of defecation. Blood may also drip into toilet or stain toilet paper
Anal fissure: diagnosed from history, tearing pain with passage of bowel movements, small amount on toilet paper or on surface of stool
Diverticula bleed: painless profuse bleeding
IBD: ulcerative colitis»_space; Crohn disease
Infectious colitis: similar clinical presentation and endoscopic appearance to UC. Excluded with stool and tissue cultures, stool studies, and biopsies of colon (EHEC)
Ischemic colitis: abdominal pain followed by profuse bleeding
What is in the differential for hematochezia: AV malformation, rapid upper GIB, polyps, proctitis, rectal ulcers, colorectal cancer, radiation colitis
AV malformation
Rapid upper GIB
Colorectal cancer
Polyps: asymptomatic and are most often detected by colon cancer screening tests, occult bleeding
Proctitis: insidiously with intermittent rectal bleeding, passage of mucus, and mild diarrhea associated with <4 small loose stools per day (mild UC)
Rectal ulcers: can present with bleeding, passage of mucus, straining during delectation, and sense of incomplete evacuation
Radiation colitis: seen weeks-years after abdominal or pelvic irradiation
What are important history points to ask GIB pt?
Prior episodes of GI bleeding
Pt’s past medical history (IBD, cancer: change in BMs, CVD, diverticulosis)
Medication use: particularly agents that are associated with bleeding or that may impair coagulation, such as NSAIs, anticoagulants, and antiplatelet agents
What are important physical points to perform on GIB pt?
Assessment of hemodynamic stability as well as examination of pt’s stool to confirm pt of hematochezia or melena
What are signs of hypovolemia?
Mild to moderate hypovolemia: resting tachycardia
Blood volume loss of at least 15%: Orthostatic hypotension (decrease in SBP of more than 20 mm Hg and/or increase in heart rate of 20 beats/min when moving from recumbency to standing)
Blood volume loss of at least 40%
Supine hypotension
How is smoking related to ulcerative colitis?
Stopping smoking is risk factor for developing UC
what is the BUN:Cr ratio in upper GIB?
30:1
What is the AST:ALT ratio in an alcoholic?
2:1
what is the anatomical division of upper GIB vs lower GIB?
Ligament of Treitz
what happens when beta blocker is abruptly stopped?
Rebound tachycardia
What skin finding is found in many inflammatory conditions?
Erythema nodosum
Red nodular areas on shins
Seen in pt with IBD
Describe advantages/disadvantages of radionuclide imaging
Advantages:
Noninvasive
Sensitive to low rates of bleeding
Can be repeated for intermittent bleeding
Disadvantages: Has to be performed during active bleeding Poor localization of bleeding site Not therapeutic Not widely available
Describe advantages/disadvantages of CT angiography
Advantages: Noninvasive Accurately localizes bleeding source Provides anatomic detail Widely available
Disadvantages:
Has to be performed during active bleeding
Not therapeutic
Radiation and IV contrast exposure
Describe advantages/disadvantages of angiography
Advantages:
Accurately localizes bleeding source
Therapy possible with super-selective embolization
Does not require bowel preparation
Disadvantages:
has to be performed during active bleeding
Potential for serious complications
Describe advantages/disadvantages of colonoscopy
Advantages:
Precise diagnosis and localization regardless of active bleeding or type of lesion
Endoscopic therapy possible
Disadvantages:
Need colon preparation for optimal visualization
Risk of sedation in acutely bleeding pt
Definitive bleeding source (stigmata) infrequently identified
What diagnostics should be considered when there is concern for upper GI bleeding source?
High index of suspicion: Upper endoscopy (EGD)
Must stabilize pt with IVF and blood
Moderate suspicion: nasogastric tube with lavage
Positive UGIB = coffee-ground material or bright red blood
-Can be falsely negative if bleeding has ceased or is beyond closed pylorus (duodenal bleed)
-Negative: bilious fluid indicates open pylorus, no active bleeding proximal to ligament of Treitz
-Indeterminate: no blood or bile. Do upper endoscopy
What is the initial management of acute lower GI bleed?
Supportive: IV access, appropriate setting (outpatient/inpatient/ICU), O2, IVF, blood products, assessment and management of coagulopathies
In pts with ongoing bleeding or high-risk clinical features:
- colonoscopy should be performed within 24 hours of presentation after adequate colon preparation to potentially improve diagnostic and therapeutic yield
- Perform colonoscopy as soon as pt has been resuscitated and adequate bowel preparation (typically 4-6 L of polyethylene glycol) has been given
- -nasogastric tub may help with getting prep down
What are considerations for blood transfusion with packed RBCs?
First type and screen if hemoglobin is stable and no acute bleed
Type and cross (and hold vs transfuse)
- Young pts without comorbid illness may not require transfusion until hemoglobin <7g/dL
- Older pts and those who have more severe comorbid illnesses such as CAD require >9 g/dL
- *Pts with active bleeding and hypovolemia may require a blood transfusion despite apparently normal hemoglobin
Obtain iron studies before transfusion because afterwards, they are inaccurate
What are some potential complications or risks in pts with ulcerative colitis?
Toxic megacolon (emergency -> surgery for colectomy)
Primary sclerosing cholangitis (M>F)
Ankylosing spondylitis
Pyoderma gangrenosum
What are some potential complications or risks in pts with Crohn disease?
Fistulas/strictures
Fissures
Pigmented gallstone formation
Malabsorption
What are some potential complications or risks in pts with both ulcerative colitis and Crohn disease?
Colon cancer
*DVT
How fast can potassium chloride (KCl) be given through peripheral IV?
10 mEq/hr (otherwise irritating to vein)
How many g/dL would the hemoglobin raise from 1 unit of packed red blood cells (PRBCs)?
Giving 1 unit of PRBCs should increase Hgb by 1g/dL
During acute IBD flare, what is the primary treatment?
Corticosteroids (IV or PO)
What is the gold standard for colorectal cancer screening?
Colonoscopy
Every 10 years
Requires less frequent screening
Screening and diagnostic follow-up of positive findings can be performed during same exam
Describe colorectal cancer screening strategies: stool-based tests
Guaiac-based fecal occult blood test (aFOBT)
Every year
No prep. Can be done at home
Fecal immunochemical test (FIT)
Every year
More accurate than gFOBT
No prep. Can be done at home with one sample
FIT-DNA
Every year or 3 years
More false-positives than FIT but better sensitivity
Describe colorectal cancer screening strategies:CT colonography, flexible sigmoidoscopy, flexible sigmoidoscopy with FIT
CT colongraphy
Every 5 years
Flexible sigmoidoscopy
Every 5 years
Less benefit than with FIT. Declined in US
Flexible sigmoidoscopy with FIT
Scope every 10 years, FIT every year
Declined in US
Option for pts who want endoscopic screening but limit exposure to colonoscopy
