Small Bowel Conditions Flashcards
Classification of SBO
- Functional (ie. pseudoobstr. or ileus) - treated medically
- Mechanical
a. Partial (can pass some liquid or gas) vs complete (nothing passes)
b. Simple obstruction vs closed loop (bowel twisting)
c. Extra-luminal vs intra
d. Gangrenous vs non-gangrenous
Main importance of identifying SBO early:
Prevent the evolution of SBO into strangulation which increases morbidity and mortality
Aetiology of SBO:
Can be intra or extraluminal as well as extrinsic.
The main 2 causes are Adhesions and hernias!!!
Neoplastic obstructions are usually mets rather than primary lesions, these lesions often can cause lead points for intussusception (need a lead point in adults)
Strictures are a fairly common cause and can be caused by inflammatory condition [Crohns]; RADIATION INJURY; TB
Matted groups of LN can compress from outside like in Abdo TB
Hematomas can compress post trauma
Gallstones in the bowel from a cholecystoenteric fistula
Pathophysiology of SBO:
Obstruction
-> peristalsis increases to push past obstruction [colicky pain early]
-> eventually SB expands with gas and fluid [distension]
-> increased bacterial proliferation
-> increased oedema of bowel wall and electrolyte and fluid transport -> compromised [dehydration & hypovolaemia]
-> eventually decreased venous return
-> ultimate arterial blood flow and gangrene
Dx of SBO:
Made primarily off history and exam, confirmed with XR
Features of SBO on Hx
Ask about prev. surgery (adhesions)
LOW or cancer warning signs
Hernias
IBD hx
Previous irradiation
prior episodes of SBO
Symptoms of SBO on Hx to elicit
Abdo discomfort +- colicky pain
Abdo distension
N&V and bile stained vomiting (proximal) or faeculant vomit (distal)
Obstipation
Clinical Signs of SBO
tachycardia
hypotension (fluid loss)
pyrexia and local tenderness, guarding = perforation
Gaseous distension
Prev. surgical scars
vigorous peristalsis if presenting early enough
Masses ?mets, TB
Virchows node!
Blood on rectum exam = masses vs interssusception
Investigations for SBO
Electrolytes (degree of dehydr.); WCC (can be elevated); lactate and acidosis may hint at bowel necrosis
Abdo XR - dilated loops of small bowel (more than 3cm) and not large bowel
- fluid levels in bowel
- free air = perforation and immediate
- might be able to see a gallstone for FB
CT - might be needed in complex cases or if malignancy is suspected
Initial management of pt. with SBO
CONSERVATIVELY
DRIP AND SUCK (IV AND NGT Draining stomach)
if pt. is not improving or deteriorates then surgery (adhesiolysis) is necessary with open lapatomy
possible need to remove non-viable bowel and anastomose or create stoma
Causes of Small bowel perforation
SBO
Spontaneous:
- TB
- Typhoid
- CMV
- Malig.
- Crohns
- Steriods
- Radiotherapy
How does an immunocomprised pt. present with SB perf.
FEW Clinical signs
Sometimes just a general malaise because immune system too comprised to mount a proper response
Consider CMV, TB, typhoid
Short bowel syndrome pathogen. and presentation and outcome
In pts. after extensive small bowel resection
Present with incapacitating diarrhoea, steatorrhoea and malnutrition
Inevitable in pts. with less than 100cm of S bowel left
Lifelong Total parenteral nutrition of SB transplant neccessary
Neuro-endocrine neoplasms location
Found anywhere in GIT but most commonly in ileum
Can also occur in lung, thymus, and ovary
NEN (neuro-endocrine neoplasm) features and symptoms
Have the potential to metastasize (mainly to liver) and produce and secrete metabolic products mainly serotonin.
Cause a CARCINOID SYNDROME (usually have mets to cause this):
- Episodic flushing
- Severe diarrhoea and abdo cramps
- Wheezing
- Peripheral oedema
Can also cause carcinoid heart disease with plaque like deposits in valves and endocardium.
