this is the pathophys of ileus activation of inhibitory spinal reflex arcs-- what prevents? [insert word] stress generates endocrine & inflammatory mediators (promotes)

spinal epidural prevents surgical stress promotes

Intestinal obstruction Flashcards by IFUNANYA CHRIS-UKAH

caused by decreased intestinal blood flow causing ischemia and subsequent reperfusion damage that may progress to mucosal injury, tissue necrosis & metabolic acidosis

mesenteric ischemia

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3 major GI arteries off the abdominal aorta

celiac axis
SMA
IMA

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3 primary causes of mesenteric ischemia

arterial embolism
arterial thrombosis– in those w preexisting mesenteric artherosclerosis
non-occlusive etiology– severe systemic illness w/ systemic shock usually d/t reduced CO (hypovolemia)

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symptoms include

severe, poorly localized, post-prandial abdominal pain w/ sorta normal abdomnial exam
not really relieved w/ opiods
N/V/D common
if chronic– wt loss & sitophobia
later dz– distention, ileus, melena, hematochezia

mesenteric ischemia

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how to revascularize a mesenteric ischemia caused by embolism vs thrombosis vs venous thrombosis if WITHOUT peritoneal signs?

embolsim– early laparotomy w/ embolectomy
arterial thrombosis– bypass graft or basloon dilation angioplasty w/ stenting
venous thrombosis– systemic anticoag (heparin, warfarin)

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if there are peritoneal signs or signs of perforation or gangrene, how are acute mesenteric ischemias treated?

emergent surgical exploration via laparotomy (after stabilization) to restore flow & resect nonviable bowel

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transient impaired persistalsis in intestine causing gas & fluid accumulation in bowel
# 1 cause is post-op
typically resolves in 2-3 days; if longer then its post-op ileus

ileus (functional)

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this is the pathophys of ileus

activation of inhibitory spinal reflex arcs– what prevents?
[insert word] stress generates endocrine & inflammatory mediators (promotes)

spinal epidural prevents
surgical stress promotes

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other causes of post-op ileus

somatic & visceral trauma activating mast cells, etc
gut handling & anastomosis interferes w/ electromechanical coupling
fluid overload/ electrolyte abnormalities
opioid analgesia decreases motliti

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slower onset of vague mild abd pain & bloating; N/V poor appetite; obstipation
NO CRAMPING
distended abdomen w/ tympany and decreased or no bowel sounds

ileus

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expected imaging for ileus on plain film

nonspecific bowel gas pattern; increased gas

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how can contrast help r/o mechanical SBO?

if the contrast does not reach cecum in 4 hrs then r/o mechanical SBO

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how is ileus managed? (4)

Admit for watchful waiting & hydration
correct underlying cause
+/- NGT; NPO till resolved; gum chewing?
d/c meds (opiates)

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general cause of FUNCTIONAL SBO

bowel wall or splanchnic nerve dysfunction

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are adnesions, hernias, volulus aand neoplasms luminal, mural or extraluminal?

all are extraluminal except neoplasms which are mural

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differentiate close vs open ended SBO in terms of movement. Which is typically luminal?

closed has 2 points and prevents any movement of contents; can affect blood supply
open has one point and affects with prograde movement; typically luminal

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whats a complicated obstruction?

affects circulation with resultant ischemia, infarction and perforation

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what are the 3 specific mechanical obstructions in SBO that we talked about

intussception
volvuus
gallstone ileus

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invagination of segment of bowel into another causing triad of vomiting + abdominal pain + blood per rectum (currant jelly stools) in kids esp after viral infection

intussception

axial twist of segment around its mesentery → closed loop obstruction and variable degree of vessel obstruction

volvulus

pathophys of SBO; fill in the blank

obstruction causes progressive dilation of the intestine ____ to blockage while ____ to the blockage, it’ll decompress as luminal contents pass
air swallowed & bacterial fermentation cause gas accumulation

1st space: Proximal
2nd space: distal

most common cause for SBO

adhesions

distal vs proximal distention– which is more associated w/ vomiting? which is more associated with distention?

Proximal SBO: acute colicky pain with bilious vomiting
distal SBO: progressive with distention (distal-distention)

PE of distention, hyperactive high-pitched BS (early), hypoactive BS later, fever, tachycardia, TTP

SBO

what is the uright XR finding for SBO? when do you get a CT?

plain film-- increased air or multi-height air fluid level (flat straight lines ladder) CT if patient has fever, tachycardia, leukocytosis, or localized abd pain

how is SBO managed?

* ADMIT * aggressive fluid resus * analgesia and antiemetic tx PRN * NGT (aka bowel decompression) * early surgical consult * abx prophylaxis * NPO * ambulation and close observatoin

# what is this? how is it treated? * happens when inflammation & adhesions after cholecystitis causes choleocystenetic fistula via which gallstones enter the bowel and goes to either stomach or down the SB. * makes up a quarter of the nonstrangulating SBO in over 65yo; * most happen at the terminal ileus

gallstone ileus surgically corrected

functional obstruction causing massive acute colonic dilation in absence of any mechanical obstruction, usually at the cecum or right hemicolon with mortality rate of 40%

acute colonic pseudo-obstruction (Ogilvie's Syndrome)

explain laplace's law & which condition it's the most relevant to. What are 4 things it could cause?

* the intraluminal pressure needed to stretch the wall of a hollow tube & the diameter of that same tube are inversely related * most relevant to Ogilvie's syndrome * implications-- ischemia, serosal splitting, herniation, perforation

3 etiologies of ogilvie's syndrome

retroperitoneal trauma serious infection cardiac dz (MI or CHF)

most common presentation of ogilvie's syndrome

**debilitated**, **hospitalized** patient w/ **multiple medical problems** and **history of many surgical conditions.**

what do you need to diagnose ogilvies? (3)

signs & sx; history CBC, CMP plain films of adomen

first thing to do when managing ogilvies

r/o mechanical obstruction! - need to see colonic air in all segments; if not visible, get barium enema! - aggressive management of underlying issues & stop narcotics

how is < 9 cm cecum ogilvie's managed? give 4 examples

conservatively - prevent consipation - NPO, decompression, correct lytes, tx infection, etc

if conservative tx isn't working what are 3 ways to treat ogilvies?

1. sympathetic blocker (ocretotide) then cholinesterase inhibitor (neostigmine) 2. colonsocopic decompression to reduce perforation risk 3. surgery for perforations or mechanical obstructive risk

# what is the condition? radiological finding: marked isolated large bowel dilation (likely R side), diaphragm elevated

ogilvie's

# what is the condition? radiological finding: marked isolated large bowel dilation (likely R side), diaphragm elevated

ogilvie's

PE findings with ogilvie's is most similar to what other condition?

SBO

if patient with sx of SBO is not clinically stable what do you do? if they are stable then what?

* unstable-- laparotomy * stable-- XR or CT

if person w/ sx of SBO shows signs of vascular compromise or perforation on imaging, what next? what if it shows complete or partial obstruction instead?

* vascular comp or perf-- laparotomy * any obstruction-- NPO, NGT, IV fluids

what happens if person with partial obstruction doesn't resolve in 1-2 days? what if its complete that doesnt resolve?

* unresolving partial-- upper GI/SB follow-thru or enteroclysis (if it doesnt resolve then laparotomy) * unresolving complete-- laparotomy

which lab is essential in SB infarction or acute mesenteric ischemia?

**lactate/lactic acid** (NOT LDH)

most common, but still rare neuroendocrine tumors from enterochromaffin cells that mostly happen in GI tract of kids; tend to be incidental findings

carcinoid tumor

what is the classic carcinoid traid?

**diarrhea, flushing & wheezing respiration** (also **PERIODIC abd. pain**, tachycardia, hypotension)

best screening test for carcinoid tumors? how is it treated?

screen: 24hr urinary 5-HIAA treatment: surgery, chemo for carcinoid syndrome