Colorectal 1 Flashcards
large bowel obstruction MC occurs where
sigmoid colon
bc site where stool becomes more solid
LBO cecum
most likely to perforate if obstruction here due to thinnest wall
LBO etiologies
MC 2/2 carcinoma
can be 2/2 diverticular dz, volvulus, hernia, benign growth
LBO pathophysiology
obstruction leads to massive dilation above obstruction
causes mucosal edema and impaired venous and arterial blood flow
ischemic bowel wall loses integrity and becomes compromised = mucosal permeability
mucosal permeability in LBO causes
bacterial translocation
systemic toxicity
dehydration
electrolyte abnormalities
symptoms of obstruction
deep, cramping pain
constipation/obstipation
abdominal distention
feculent vomiting
signs of obstruction
abdominal distention and tympany
high pitched metallic tinkles, w/ rushes and gurgles on auscultation
localized tenderness
what indicates an emergency LBO
fever, peritoneal signs and abdominal rigidity
might suggests peritonitis and perforation - surgical emergency
TOC for LBO
CT Abdomen/Pelvis, with IV and Oral contrast
CT findings in LBO
haustral markings
air fluid levels and dilated colon
CXR in LBO
air under the diaphragm
can show transition point
tx of LBO
initial stabilization and prep for possible surgery
I.e. fluid resuscitation, zosyn, NG tube
Ogilve’s syndrome
colonic dilation and ileum that mimics obstruction without transition point or mechanical obstruction
MC site of Ogilve’s syndrome
right colon and cecum commonly affected
risk factors of Ogilve’s syndrome
medical or surgical illnesses such as infection, trauma, cardiac disease
Ogilve’s syndrome tx
supportive - hydration and lytes and bowel rest
colonoscopic decompression may be attempted if supportive doesn’t work but surgical intervention is not encourage
medications that could cause Ogilve’s syndrome
opioids
anticholinergics
muscle relaxants
rotation of intestinal segment on mesenteric axis
volvulus
volvulus results in
partial or complete lumen obstruction
may compromise the blood supply = closed loop obstruction
can’t back up, rapid wall extension and increased risk of perforation
volvulus etiologies by country
chronic constipation (Western)
high fiber diet (developing nations)
volvulus pathophysiology
overloaded sigmoid colonic loop
stretching of mesentery and increasing susceptibility of torsion
populations predisposed to volvulus
institutionalized pts with neuropsychiatric disorders
MS, Parkinson disease, spinal cord injury
pts in nursing homes due to prolonged recumbency and chronic constipation
volvulus etiologies
excessive use of laxatives, cathartics, enemas (increased stimulation stretches it)
pregnancy or large pelvic tumors
chagas disease
s/s sigmoid volvulus etiologies
60-70% pts present acutely with LBO symptoms (cramping, obstipation, abdominal distention)
subacute or chronic symptoms (episodic constipation, less severe abdominal pain, distention, obstipation)
Xray sigmoid volvulus findings
massively dilated single bowel loop
concavity points to LLQ
coffee bean sign
s/s cecal volvulus
severe, intermittent colicky pain in RLQ , vomiting and obstipation ensues
less distention than sigmoid, more likely to have vomiting
cecal volvulus plain film
dilated kidney bean shaped cecum
concavity pointing to RLQ
cecal volvulus
inadequate for diagnostics
tx of cecal volvulus
operative detorsion
sigmoid volvulus tx
no strangulation or perforation = endoscopic decompression
strangulation or perforation = surgery
diverticulum
small finger like out-poaching of mucosa thru colonic wall at site of penetrating arteries
where do most diverticula occur
sigmoid colon and left sided colon
due to pressure sites
diverticula risk factors
increase with age
likely due to lack of fiber
obesity
asymptomatic diverticula
found incidentally during C-scope or BE
diagnosed with diverticulosis
diverticulosis tx
supplemental fiber in the diet
diverticulitis pathophysiology
- erosion of the diverticular wall due to increased intraluminal pressure and thickened matter
- outlet obstruction by fecalith or undigested food
diverticulitis epidemiology
mc in middle age to elderly population
right sided diverticula more common in asian population
s/s diverticulitis
mild to moderate aching abdominal pain in LLQ
n/v, constipation, diarrhea, +/- BRBPR
fever
symptoms are usually mild, more acute with perforation
diverticulitis on PE
generalized pain –> increased size causes localized pain
high fever
increased then decreased BP
painful heel tap
TOC diverticulitis
CT abdomen/pelvis w/contrast
diverticulitis evaluation
CT scan, barium enema contraindicated
Labs: CBC, chem panel, blood cultures x2 q 15 minutes
+/- amylase, lipase, liver enzyme, c-diff screen
mild diverticulitis tx
mild symptoms and no peritoneal sings
clear liquid diet, ABX 7-10 days
ABX used in mild diverticulitis
Cipro + Flagyl, Augmenting or Avelox
inpatient medical diverticulitis tx
NPO with IVF
IV antibiotics (zosyn, unasyn) (3-5days switch to PO)
consult if severe or septic
IR percutaneous catheter
who gets surgical tx diverticulitis
peritonitis, large abscess, fail to improve with medical management in 2-3 days
OR significant peritonitis/perforation at time of presentation
surgical tx diverticulitis
NOP, fluid resuscitated
brand spectrum IV ABX begun
abdominal laparotomy + colostomy (elective takedown)
repeated episodes of diverticulitis
episodes of 3+ diverticulitis
consider elective colon resection (no colostomy)
colitis types
Infectious, ischemic, IBD
RARE: microscopic, necrotizing enterocolitis, allergic colitis
C diff colitis
inflammation and infection of the colon
typically gotten from healthcare workers and contaminated clothing and equipment and ABX use kill off other natural gut flora causing C Diff to develop
C diff colitis MC due to what ABX (4)
- ampicillin
- clindamycin
- 3rd gen cephalosporins
- fluorquinalones
risk factors for developing C diff colitis
elderly, debilitated, immunocompromised
multiple abx/prolonged use
entereal feeding, PPI use, DI dz, surgery
C diff colitis s/s
w/in 2 months of after ABX use
can occur after just ONE dose of ABX
watery green, foul smelling diarrhea w/mucus and cramping
SIGNIFICANT LEUKOCYTOSIS
C diff colitis workup
Diarrheal stool samples ONLY:
enzyme immunoassay (EIA)
PCR assay of C diff toxin
flexible sigmoidoscopy
tx of C diff colitis
stop abx that contribute to problem
ABX 10-14days
do NOT repeat
ABX less likely to cause C diff colitis (5)
vancomycin sulfonamides macrolides IV aminoglycoside tetracycline
ABX used to tx C diff colitis
Flagyl/Metronidazole (PO, IV) 500 mg q8/250q6
Vancomycin (Oral) 125 PO
C diff colitis recurrence
typically occurs in 1-3 weeks
repeat stool assays dont work
NOT related to drug resistance so can use same drug
call I&D, high chance of reoccurrence
severe C diff colitis if:
- leukocytosis >15,000
- serum creatinine >1,5x pt baseline
- shock, hypotension
C diff colitis tx
VANC preferred
rarely, total colectomy
fecal microbiota transplant
fecal microbiota transplant
normal non pathogenic bacteria from donor stool can repopulate in tract of recipient and stop unchecked C Diff growth
ischemic colitis
low blood flow to bowel causes mucosa to become ischemic and slough
typically 2/2 trauma, surgery, syncope
areas most vulnerable to ischemic colitis
splenic flexure
rectosigmoid junction
ischemic colitis s/s
LLQ pain, cramping tenderness
frankly blood diarrhea following inciting event
ischemic colitis tx
supportive care (NPO, hydration)
daily labs to monitor progress
empiric ABX
lower GI bleed epidemiology and etiologies
mc in men, elderly
- diverticular bleeding
- angiodypslasia/AVM
- benign anorectal dz
- IBD
- neoplasm
lower GI bleed painless and copious
diverticular bleed
lower GI bleed self limited, painless, slow and RECURRENT
AVM/angiodysplasia
lower GI bleed painful bloody, weight loss, mucous
inflammatory colitis
lower GI bleed painful, hx of event with low flow
ischemic colitis
lower GI bleed insidious bleeding painless
colon ca
lower GI bleed painful or painless, blood on toiled
anorectal disease
lower GI bleed management
try to qualify loss (rectal exam)
lab work up: CBC, chem panel, PTT, PT/INR, T&C
GI consult
how to determine if lower GI bleed is ongoing?
serial H&H to see rate of decline
remember fluids will decrease
lower GI bleed workup
colonoscopy initially (tx and dx)
CT scan, bleeding scan, mesenteric angiography
