small and large BO, anal and rectal dz Flashcards
1
Q
vascular supply to the small intestine is primarily from
A
superior mesenteric artery
2
Q
List the extraluminal causes of small bowel obstruction
A
- Post-op surgical Adhesions (60%)
- Neoplasms (20%)
- Hernias (10%)
- malrotation
- intraabdominal abscess
3
Q
What are the some intraluminal causes of small bowel obstruction
A
- intussception
- neoplasm
- crohn’s
4
Q
In a patient who presents with abd pain, why is it important to ask for a h/o abd surgery
A
- adhesions are present in 2/3 of patients after abd surgery
- post op surgical adhesions account for 60% of small bowel obstructions
5
Q
small bowel obstruction leads to what volume status
A
- hypotension
- intravascular fluid depletion -> edematous wall leads to fluid sequestration in lumen
6
Q
Obstipation
A
- inability to pass either gas or stool
7
Q
clinical presentation
- abd pain, intermittent -> steady
- abd distension
- N/V
- constipation
- obstipation
- high pitched or absent bowel sounds
- typmany on percussion
A
obstruction
8
Q
What films would you order to assess for small bowel obstruction?
A
- plain films: supine and upright
- CT scan
- plain films are negative but high clinical suspicion
9
Q
List the red flags when assessing for SBO -> surgery consult
A
- pneumoperitoneum
- retroperitoneal air
- peritoneal signs
- shock
10
Q
List signs on xray/CT that are consistent with obstruction
A
- dilated proximal bowel
- distal collapsed loops
- air fluid levels
- bowel wall thickening > 3 mm
- sub-mucosal edema
- ascites
11
Q
management of small bowel obstruction
A
- volume resuscitation, NPO, decompression with NG tube, abx
- consult surgeon
- only 1/4 of patients with SBO require surgery
12
Q
What percentage of partial small bowel obstructions resolve spontaneously
A
80%
13
Q
Name two ways to differentiate between complete and partial small bowel obstruction
A
- cessation of passage of stool or gas > 12-24 hrs supports complete SBO
- absence of air or fluid in distal small bowel or colon supports complete SBO
14
Q
List causes of complicated bowel obstruction
A
- complete obstruction
- close loop obstruction
- incarcerated hernia: causes highest complication rate
- bowel ischemia, necrosis, or perforation
15
Q
List three causes of intestinal strangulation
A
- strangulated hernia
- volvulus
- intussusception
16
Q
clinical presentation
- rebound tenderness
- tenderness to percussion
- pain with light palpation/bumps
- diminished bowel sounds
A
peritonitis
17
Q
currant jelly stools is characteristic for
A
intussusception
18
Q
clinical presentation following abdominal surgery
- obstipation
- intolerance of oral intake
- absent or hypoactive bowel sounds
A
paralytic ileus
- certain degree is normal following surgery
- due to anesthetics, narcotics, and manipulation
- more likely with larger incisions
19
Q
How can you determine (using symptoms) if an ileus is physiologic or pathologic post operatively
A
- no return of bowel function in 4-6 days post-op
- absence of flatus or stool 6 days post-op
- N/V requiring cessation of PO intake
- requirement for NGT after day 5 post-op
20
Q
how is paralytic ileus diagnosed
A
- plain films
- KUB shows dilated loops and air in small bowel AND colon
21
Q
management of paralytic ileus
A
- fluids
- pain managment (not narcotics)
- NGT in some
- PPN, TPN
- ambulate
22
Q
blood supply to large bowel
A
- SMA and IMA
23
Q
percentage of bowel obstructions in small and large bowel
A
- small bowel 80%
- large bowel 20%
24
Q
List the causes of large bowel obstruction
A
- adenocarcinoma (65%)
- stricture due to diverticulitis/ichemia
- volvulus
- IBD, foreign body, fecal impaction
25
what films would you order when assessing for large bowel obstruction
1. plain films: **supine and upright**
2. CXR: look for free air under diaphragm
3. Gastrograffin enema
* if xrays are unclear
* localization for surgery
4. CT scan if diagnosis still in question
26
managment of large bowel obstruction
1. IV fluids, NPO
2. abx
3. decompression if vomiting
4. can start bowel cleanse to prep for surgery
27
what is a volvulus
* abnormal twisting of a portion of the GI tract, usually intestine, which can impair blood flow
28
List the two most common types of volvulus
1. sigmoid volvulus
2. cecal volvulus
29
which type of volvulus is the most common? Mean age of patients who get it?
* sigmoid volvulus
* 70 yo
30
imaging is suggestive of
* KUB/upright: U shaped **"bent inner tube" sign**
* CT scan: **whirl pattern** and **birds beak**
sigmoid volvulus
31
tx of sigmoid volvulus
* **reduction**
* flexible sig to decompress and de-rotate
* interval surgery to resect redundant sigmoid and fix colon so it can not rotate again
32
cecal volvulus commonly affects what age group
mean age 33-53 yo
33
imaging suggestive of
* KUB/upright: **comma** or **coffee bean sign** with air fluid levels
cecal volvulus
34
tx of cecal volvulus
1. right colectomy
2. cecopexy with cecostomy tube: if pt unstable
3. cecostomy tube alone in debilitated pt
35
What line seperates innervation of anus? Where is somatic innervation?
* pectinate or dentate line
* somatic innervation is below line: pt feels pain here
36
causes of hemorrhoids
* prlonged sitting, straining, pregnancy, advanced age
37
why do hemorrhoids itch
* swelling in the tissue allows fecal mattter to infiltrate and cause localized dermatitis
38
clinical presentation
* bright red blood per rectum - on toilet paper or stool (not mixed in)
* pruritus
hemorrhoids
39
what is the most common cause of rectal bleeding
* internal hemorrhoids
40
differentiate between internal and external hemorrhoids
1. internal: above dentate line
* not painful
* may bleed and prolapse
2. external: below dentate line
* do not bleed
* May thrombose
* pain, itching
41
diagnostic evaluation of hemorrhoids
1. rectal exam
2. CBC
3. anoscope
4. if in doubt, flexible sigmoidoscopy vs colonoscopy
42
differentiate between the 4 classes of internal hemorrhoids
* **1st degree**: bulge in anal canal
* **2nd degree**: protrude with defecation, spontaneous reduction
* **3rd degree**: require manual reduction
* **4th degree**: permanently protruded
43
list the two options for hemorrhoid treatment
1. non-operative symptomatic relief
* **rubber band ligation** of grade II and II **internal** hemorrhoids
* will cause necrosis
2. surgical hemorrhoidectomy
* internal or external hemorrhoids with extensive thrombosis, pain, and persistent bleeding
44
List the 4 types of anorectal abscesses due to obstruction of perianal crypt glands
1. perianal (60%)
2. ischiorectal
3. intersphincteric
4. supralevator
45
causative organisms of anorectal abscess
* e-coli
* proteus
* strep bacteriodes
46
tx of anorectal abscess
1. surgical drainage: **all require I&D**
2. possible broad spectrum abx
3. wound care
47
untreated perianal infections can lead to
Fournier's gangrene
48
what is a anal fistula
* abnormal connection between anal canal (internal opening) and the perianal skin (external opening)
* 50% chance after abscess
49
List the causes of fistula
* opened or ruptured abscess
* crohns disease
* diverticulitis
* fistula in ano
50
managment of fistula
* fistulotomy: unroofing the fistula tract to allow healing
51
tx for fistula in ano
* delineation of fistula tract
* drainage and curettage of fistula tract
* placement of **seton**
52
what are anal fissues
* linear tears in the lining of the anal canal **below** the level of the dentate line
53
causes of anal fissues
* foreign body
* very hard bowel movement
54
anal fissues are most common where
* posterior wall
* lowest blood supply
55
clinical presentation
* severe rectal pain with BM
* afraid to have a BM
* rectal bleeding
anal fissues
56
how is anal fissues diagnosed
* felt on DRE
* if unsure, get flex sig or colonoscopy
57
tx of anal fissues
* aim for soft, formed BM
* nitroglycerin ointment
* reduced spasm and increases blood flow
* if not healed in 3-4 weeks, needs surgery
