Lecture 1 - Large Intestine Flashcards by Cal Schiller

Antibiotic associated diarrhea is not the same as antibiotic associated colitis.

True colitis is nearly always a result of infection with c. diff.

If a patient comes in w/ diarrhea OR gets diarrhea in the first 2 days, we typically don’t consider C diff.

Remember, diarrhea acquired on day three or after, we should consider C diff.

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Fluoroquinolones
Ampicillin
Clindamycin
Cephalosporins (3rd gen)

Most common causative agents of C diff

however, almost all have been implicated

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Watery, greenish, foul smelling stool that may contain mucus

Abd cramping

Mild leukocytosis on CBC (<15,000)

Mild-moderate antibiotic associated colitis

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Profuse diarrhea and fever (<101.3)

Hypoalbuminemia (serum albumin < 3g)

PLUS 1 of:

Abd pain w/ diffuse TTP

leukocytosis on CBC >15,000

Severe disease

Antibiotic associated colitis

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What are the reqs for a SEVERE version of antiobiotic associated colitis?

Profuse diarrhea/fever (<101.3)
Hypoalbuminemia (<3g/dL)

AND at least one of the following…

3a. Abd pain w/ diffuse TTP
3b. Leukocytosis on CBC > 15000

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Admission to ICU
HOTN (w/ or w/o vasopressors)
Fever > 101.3
Ileus of significant/visible abd distension
Mental status changes
WBC>35,000
Serum > 2.2
End organ failure

FULMINANT antibiotic associated colitis

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Result of severe inflammation

Manifests as raised yellow or off-white plaques up to 2 cm in diameter

Pseudomembranous colitis

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Study of choice for Antibiotic associated colitis?

What’s another option?

PCR = study of choice

Another option is Enzyme Immunoassay (EIA), which requires two samples

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For antiobiotic associated colitis, when is imaging warranted? What are we evaluating for?

When there’s evidence of fulminant disease. Used to evaluate for toxic megacolon, perforation, or other complications

contrast enhanced CT

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What are some complications of fulminant antibiotic associated colitis?

Hemodynamic instability
Hypercoagulability (from hypoalbuminemia(
Respiratory failure
Metabolic acidosis
Toxic megacolon
Bowel perf

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What are general tx measures for antibiotic associated colitis (regardless of severity)?

Admission
***D/c offending antibiotic!
Infection control measures
Correct fluid/electrolyte disturbances

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First line tx for MILD/MODERATE antibiotic associated colitis?

Metronidazole 500 mg PO TID x 10 days

alternate = vancomycin 125 mg PO QID x 10 days

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What would you do if there’s no clinical improvement w/ metronidazole therapyin 5-7 days?

Switch to vancomycin

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Why not just start w/ vancomycin?

COST and decrease in likelihood of abx resistance

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Tx for SEVERE antibiotic associated colitis?

Vancomycin 125 mg PO QID x 10 days

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Tx for FULMINANT antibiotic associated colitis?

Vancomycin 500 mg PO QID

AND

Metronidazole 500 mg IV q8 hrs

AND

Vancomycin PR 500 mg QID

AND EARLY CONSULTATION

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A quarter of patients w/ abx associated colitis will relapse w/ 14 days…

What’s the tx for the FIRST relapse?

Repeat course of abx

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What’s the tx for a subsequent relapse (i.e., third case) of antibiotic associated colitis?

7 WEEK taper of vancomycin

Consider probiotics/fecal transplant

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Total or segmental colonic dilatation

Non obstructive

LARGER THAN 6 CM (must be assessed by rad)

Systemic toxicity

Toxic megacolon

complication of IBD but typically ulcerative colitis

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Radiographic evidence of colonic distension (>6cm)

PLUS 3 of:

2a. Fever (100.4)
2b. Pulse (>120)
2c. Leukocytosis (>10,500)
2d. Anemia

PLUS 1 of:

3a. Dehydraion
3b. AMS
3c. Electrolyte abnormality
3d. HOTN

Toxic megacolon

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Evidence req’d for toxic megacolon?

Radiographic evidence of colonic distension (>6cm)

PLUS 3 of:

2a. Fever (100.4)
2b. Pulse (>120)
2c. Leukocytosis (>10,500)
2d. Anemia

PLUS 1 of:

3a. Dehydraion
3b. AMS
3c. Electrolyte abnormality
3d. HOTN

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Tx for toxic megacolon?

Reduce colonic distension

Correct fluid/electrolyte disturbances

Treat toxemia/precipitating factors

Surgical consult

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Sac like protrusion of the colonic wall?

diverticulum

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Most are asymptomatic (“incidental findings”)

Vary in size/number

Nearly universally present in sigmoid/descending colon

Pathogenesis related to increaed intraluminal pressure (low fiber/insufficient water intake)

Colonic diverticula

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What is the diverticulosis? Tx/work up?

Presence of diverticula (usually found incidentally/typically asymptomatic) No specific tx or further work up is necessary (recommend increase in dietary fiber/water)

Diverticular bleeding is typically self-limited. However, pt may complain of what?

Painless hematochezia (blood that squirts into the toilet) Typically no other ssx

Tx for diverticular bleeding?

With active bleeding, resuscitation/stabilization (CONSIDER UPPER GI BLEED) and endoscopy Pts w/o active bleeding, refer for scope (colonoscopy)

Inflammation/perforation of a diverticulum (typically a micro-perforation and results in an intraabdominal infection). How's the pt present?

Diverticulitis pt presents w/ abdominal pn/tenderness in LLQ Fever N/V

Diverticulitis PE? Labs?

LLQ TTP (20% will have a mass) Fever Lab = leukocytosis (w/w/o +FOBT)

WHAT DO WE NOT GIVE A PT W/ DIVERTICULITIS?

NO ENDOSCOPY

Diagnostic imaging for diverticulitis?

Abd CT | but not always necessary in pts w/ mild dz, ie, mild TTP w/ no fever

Mild diverticulitis tx? Type of abx?

Outpatient Oral broad spectrum abx: 1. Metronidazole + Cipro 2. Metronidazole + TMP-SMX 3. Amoxicillin-Clavulanate (7-10 days) Clear liquid diet (advance as tolerated)

What disease/condition? Clear liquid diet Oral broad spectrum abx: 1. Metronidazole + Cipro 2. Metronidazole + TMP-SMX 3. Amoxicillin-Clavulanate

Diverticulitis

Criteria for INPATIENT mgmt of diverticulitis?

Complicated diverticulitis as seen on CT scan Sepsis High fever (>102) Significant leukocytosis Advanced age Immunocompromise Significant comorbidities Unable to tolerate PO intake Failure of outpatient mgmt

Diverticulitis that warrants inpatient mgmt

Severe/inpatient mgmt of diverticulitis?

NPO IV broad-spectrum abx (Once inflammation is stabilized -> PO) IV fluid/electrolytes IV pn mgmt Surgical consultation

When would you transition from IV to PO abx in severe diverticulitis?

Once inflammation is stabilized

Potential complications of diverticulitis?

Perforation Abscess Fistulization Obstruction (from severe inflammation)

If a pt w/ diverticulits fails to improve after an abx regimen, what should be considered and obtained?

Consider complications, such as an abscess Obtain CT if suspecting a complication

Ssx of obstruction w/o mechanical lesion? Presence of bowel dilation on imaging

Acute colonic pseudo-obstruction (Ogilvie Syndrome)

When does acute colonic pseudo-obstruction occur?

Shortly after surgery ("postsurgical") Post-trauma Medical inpatients (e.g., respiratory failure, MI, CHF)

Ssx of acute colonic pseudo obstruction?

Abd distension Abd pn Nausea/vomiting Essentials of DX: - severe abdominal distention - Postoperative state or severe medical illness - precipitated by electrolyte imbalances /meds - Absent to mild abdominal pain; min tenderness - massive dilation of cecum or R colon

What imaging might be used for ACPO? | ??f/u to determine study of choice

Plain film shows colonic dilation (USUALLY confined to cecum/right hemicolon) (CT can r/o mechanical obstruction if suspected due to malignancy, volvulus, or fecal impaction) normal cecal size is 9 cm... cecal diameter greater than 10-12 cm is associated w/ increased risk of perforation!

Torsion of a segment of the alimentary tract is called? What can it lead to? Most common site?

Volvulus can lead to obstruciton MOST COMMON SITE IS SIGMOID (can occur anywhere)

Insidious onset of progressive abd pn Continuous/severe pn at presentation Nausea Abd distension Vomiting CONSTIPATION

Sigmoid volvulus (ACPO aka Ogilvie is only absent to mild abdominal pain) Toxic megacolon from IBD or C diff would have fever; dehydration, sig abdominal pain; leukocytosis; and diarrhea, which is often bloody (instead of constipation)

PE of sigmoid volvulus?

Distended abd w/ tympany to percussion TTP (lab tests typically unremarkable)

Imaging and tx for sigmoid volvulus?

Plain abd films CT to r/o other etiologies Tx is detorsion via flex sig

Protuberance extending into the lumen of the colon, that's typically asympomatic... but may lead to?

Polyp... may lead to Bleeding Tenesmus Obstruction

Two types of polyps?

Pedunculated (connected by thinner stalk) Sessile

Four types of polyps?

1. Mucosal adenomatous 2. Mucosal serrated 3. mucosal non-neoplastic 4. Submucosal lesions

Most common polyp? Description?

Adematous Dysplastic by definition May be tubular, villous, or tubulovillous

Display a lumen w/ serrated or stellate architecture

Serrated polyps (including hyperplastic polyps)

Type of non neoplastic polyps that has no clinical significance... Includes hamartomas... which are?

Mucosal non-neoplastic Hamartomas = benign tumor-like malformations made up of an abnormal mixture of cells/tissues

Create polypoid appearance of overlying mucosa

Submuscosal lesions

Bad to see on pathology report?

adenoma dysplasia (hyperplastic, not so bad)

Inherited disorder Development of 100s+ of polyps Develop polypls by 15 Development of cancer is inevitable (requires an eventual total colectomy) ANnual colonoscopy requiered until colectomy

Familial Adenomatous Polyposis

Polyposis syndrome that presents w/ hamartomas and oral lesions

Peutz Jeghers Syndrome

Familial Juvenile Polyposis

type of hamartomatous Polyposis syndrome increased risk of colon CA

Cowden disease

type of hamartomatous Polyposis syndrome

AKA Lynch Syndrome Autosomal dominant condition Increased risk of abdominal organ cancer Use what for screening?

Hereditary Nonpolyposis Colon Cancer (HNPCC) Bethesda Criteria

Colorectal cancer risks?

IBD Smoking Family Hx (first degree relatives) Age (risk > after 45) DIet high in fat and red meat

Cancer lesions maybe present for years before symptoms begin. So?

We implement prevention and detection tests

Colorectal CA prevention tests?

Colonoscopy Flex Sig CT colonography

Colorectal CA DETECTION tests?

Fecal Immunochemical Test Hemoccult SENSA Fecal DNA

What constitutes a high risk CRC pt?

Single first degree relative w/ CRC or advanced adenoma diagnosed at age > 60 Two first degree relatives w/ CRC adenomas

What is the recommended screening for high risk patients?

Colonoscopy every 5 years beginning at age 40 years or 10 years younger than age at diagnosis of the youngest affected relative

Used for prognosis AFTER diagnosis (NOT a screening test) USed as a marker for recurrence

Carcinoembryonic Antigen (CEA)

Colorectal cancer of the right colon... ssx?

Iron deficiency anemia Weakness/fatigue

CRC of the L colon... ssx?

Change in bowel habits Blood streaked stool Obstructive symptoms

CRC in the rectum... ssx?

Tenesmus Hematochezia Urgency Decrease in caliber of stool ("ribbon stool")

What are the signs of advanced CRC?

Complete obstruction ("apple core" lesion) Wt loss Fever, chills, night sweat

Work up for CRC?

FOBT (guiac or FIT) CBC CMP UA Colonscopy

Tx for CRC?

Surgical resection (full/partial colectomy) Chemotherapy Radiotherapy

CRC prognosis?

Stage 1 = best | Stage 4 = worst