2- Bowel Obstruction Flashcards
What is defined as a blockage of the bowel that occurs when normal flow of intraluminal contents is interrupted due to functional or mechanical process?
Bowel obstruction
What is considered a partial bowel obstruction?
Fluid/air continue to pass
What is considered a complete bowel obstruction?
Cessation of passage of stool or flatus
What are the 3 major causes of a bowel obstruction?
- Extrinsic/Extra-luminal (external to bowel)
- Intrinsic (within wall of bowel)
- Intraluminal (defect that prevents passage of GI contents)
What effect does a bowel obstruction have on the lumen of proximal and distal to obstruction?
Proximal: bowel dilation and retention of fluid
Distal: Bowel compression
What two things contribute to distention sx during a bowel obstruction?
Swallowed air and gas fermentation
What is the pathophys of a bowel obstruction?
Excessive dilation → poor perfusion → ischemia → necrosis → perforation
Is a small or large bowel obstruction more common?
SBO
Adhesions, hernia, and neoplasms are RFs for SBO or LBO?
SBO
What is the most common cause of SBO?
Adhesions from prior abdominal/pelvic surgery (can develop YEARS after procedure)
Pt presents w/ hx of intermittent periumbilical cramping that is now constant focal abd pain, worse after food and w/ distention and obstipation. What are you concerned about?
SBO
SX of shock, laying flat/motionless and + peritoneal signs are RF for what?
SBO
If on auscultation you hear high pitched tinkling in pt w/ suspected SBO. Is this an early or late stage finding?
Early
If on auscultation you hear hypoactive/absent bowel sounds in pt w/ suspected SBO. Is this an early or late stage finding?
Late
What should be included on PE for pt w/ suspected SBO?
DRE
If pt presents w/ hx of vomiting before onset of pain is this more a medical condition or surgical condition?
Medical
If pt presents w/ hx of pain followed by onset of vomiting is this more a medical condition or surgical condition?
Surgical
An increased H/H on CBC for pt w/ SBO will indicate what?
Hemoconcentration, most likely due to dehydration
Elevated BUN/Cr and specific gravity on UA will also indicate dehydration
What is the benefit of ordering a CT for pt w/ suspected SBO?
ID location, severity, etiology, and complications
dilated proximal bowel w/ distal collapse, wall thickening > 3 mm, submucosal edema
What imaging will show dilated loops of bowel w/ air fluid levels?
Supine and upright Abd XR (respectively)
What finding on CXR is consistent w/ perforation?
Free air under diaphragm
If you have a VERY HIGH suspicion of SBO what is your next step?
Consult surgery to have them decide on what imaging they prefer
What is the tx for SBO?
- Admit
- Consult surgery or GI
- Trial of non-operative management (NPO, IV fluids, bowel decompression w/ NG tube, anti-emetic)
- Serial clinical monitoring for 2-5 days (improvement if decreased in distention, passage of stool, decreased NG output
What tx for SBO is diagnostic and therapeutic?
Gastrograffin
What are the indications for surgery in pt w/ SBO?
Complication bowel obstruction (worsening sx, peritonitis)
Intestinal strangulation
Worsening sx or unresolved sx w/ NG tube & bowel rest
Pt presents with significant pain w/ light palpation/ bumps, appears ill and lies completely still. What are you concerned about?
Peritonitis
A strangulated hernia, volvulus and intussusception can all cause what?
Intestinal strangulation
What is the vicious cycle associated w/ adhesions?
Surgery causes adhesions, adhesions cause obstructions, adhesion removal causes more adhesions
What is obstipation?
Inability to pass flatus or stool (bad sign)
What is defined as hypomotility of the GI tract in the absence of mechanical bowel obstruction?
Ileus
An ileus will often occur secondary to what?
Postoperative abdominal surgery (can be self limited or no return of bowel function)
Opioids, antispasmodics and anticholinergic are what type of agents? What can they cause?
Hypomotility agents
Can cause ileus
3way ABD XR will should what for pt w/ ileus?
Dilated loops of bowel
Air is present in both small and large bowel
NO air fluid levels
What is the tx for ileus?
Supportive care w/ IV fluids, lyte replacements, pain mgt (avoid narcotics, use NSAIDs), bowel rest, bowel decompression w/ NG tube
What is the most common cause of a LBO?
Adenocarcinoma (commonly of colon and rectum)
- Also: stricture, volvulus, IBD, fecal impaction, FB
The following questions are part of the hx for SBO or LBO?
Have LLQ pain w/ diarrhea?
Chronic opioid use or chronic constipation?
LBO
What will XR show for pt w/ complete colonic obstruction?
Absence of air distally in the rectum or sigmoid
What is the tx for partial LBO?
Trial of conservative therapy (surgery consult, NPO. IV fluids, decompression)
What is the tx for complete LBO?
Resection (if CA, stricture, cecal volvulus), pneumatic reduction (instussusception), enema (fecal impaction)
What is defined as abn twisting of a portion of the GI traction which can impair blood flow?
Volvulus
What are the 2 types of volvulus?
Sigmoid (more common), cecal
Age, chronic constipation, redundant sigmoid colon, colonic dysmotility and hypomotility agents are RF for what?
Sigmoid volvulus
What is the managements for sigmoid volvulus?
Flex sig to decompress and de-rotate, surgery to resect and prevent recurrence
What is the average age for sigmoid volvulus?
70 y/o
What is the avg age for cecal volvulus?
33-53 yrs
What is the tx for ceal volvulus?
Surgery
Also: volume resuscitation, lyte replacement, NPO
What will an upright ABD XR show for cecal volvulus?
Dilated cecum typically displaced medially and superiorly
What imaging is dx for cecal volvulus?
CT
What imagaing study is diagnostic and therapeutic for w/ sigmoid volvulus?
Contrast enema
