Bowel Obstruction

Question 1

Obstruction occurs via

typically occurs in

Answer 1

extrinsic compression, bowel wall abnorm, intraluminal processes

SI or rectosigmodal colon

Question 2

Mechanical obstruction results in

Over time

leads to

within 12 hrs of complete obstrution

Answer 2

inc contractility proximal and distal

proximal segment dilates w secretions/air, peristalsis stops

Intraluminal pressure rising- if high enough, impedes V/L drainage- eventually dec arterial supply

Ischemia, necrosis, perf

Question 3

Stasis of intestinal contents

Inflamm mediators released

Answer 3

proliferates bacteria (E Coli, Strep faecalis, Kleb)

activate PMNs/macros, inhibit intestinal funct (sepsis)

Question 4

Small bowel

Colon

obstruction facctors

Answer 4

Adhesion, tumors/PC, hernia

Colon ca, diverticulitis

Question 5

CM

Proximal obstruct

w persistence

colon obstruction

Answer 5

diffuse ab pain, distension, N/V/cons

pass feces, v

patients become ill, pain, emesis (biious to feculent)

distension

Question 6

PE

Early SBO

Later

Answer 6

hypoTN, tachycardia due to IV volume depletion, ab tenderness, ischemia/necrosis w PPI

High pitched, tinkling BS w rushes

hypoactive, absent

Question 7

Dx

High index of suspicion

not critically ill

findings on CT

xray

multiple air fluid levels w paucity of conon gas suggests

Answer 7

clinical features, images

OR

CT of ab/pelvis w contrast

SB dilation, air fluid, obs, ischemia

multiple distended S/L i (nonspec)

SBO

Question 8

Mx

complete BO

Answer 8

fluid resuscitation & intestinal decomp (NG tube- prevents air swallowing/intestinal dilation)

urgently for repair