Intestinal obstruction

Question 1

Volvus

Answer 1

twist/rotation of segment of bowel

always at part of bowel with mesentery

narrow base + wide lumen

Question 2

adhesions

Answer 2

sticking together

Question 3

intesussuption

Answer 3

telescoping of one hollow structure into its distal hollow structure

Question 4

atresia

Answer 4

absence of opening or failure of development of hollow structure

Question 5

which is more common, SBO or LBO?

Answer 5

SBO: 70% of cases

Question 6

RFs for SBO in adults

Answer 6

adhesions - previous surgery
hernia
Caron’s
malignancy

Question 7

RFs for SBO in children

Answer 7

appendicitis
interruption
volvulus
atresia
hypertrophic pyloric stenosis

Question 8

RFs LBO

Answer 8

age + race dependent

Question 9

what makes up the majority of LBOs?

Answer 9

colorectal malignancies, distal to the transverse colon

Question 10

Classification of BO

Answer 10

site
extent of luminal obstruction
mechanism
pathology e.g. simple, closed loop, strangulation

Question 11

SBO pathology of obstruction

Answer 11

proximal dilatation
increased secretions + distension

untreated obstruction –> ischamia –> necrosis –> perforation

Question 12

LBO pathology of obstruction

Answer 12

colon prox to obstruction dilates
increase in colonic pressure
decreased mesenteric BF
mucosal oedema

atrial supply compromised
mucosal ulceration
full thickness necrosis
perforation

Question 13

Presentation

Answer 13

vomiting
nausea
anorexia

colic occurs early
active ‘tinkling’ bowel sounds

Question 14

Why faceulent vomiting?

Answer 14

fermentation of intestinal contents in established obstruction

Question 15

What would a digital rectal exam of LBO show?

Answer 15

empty rectum
hard stools
blood

Question 16

what would sudden onset, pain, localised tenderness and distension in large bowel be?

Answer 16

volvulus

Question 17

does vomiting follow or precede pain in SBO?

Answer 17

follows

Question 18

resonance if theres gas and resonance if theres fluid?

Answer 18

tympanic - gas

dull - fluid

Question 19

Plain X-ray partial SBO

Answer 19

gas throughout abd

Question 20

in LBO what does contrast enema provide info on?

Answer 20

level, degree & type of obstruction

Question 21

Mx

Answer 21

fluid resuscitation
bowel decompression
analgesia + antiemetic

Question 22

non-mechanical obstruction

Answer 22

a dynamic obstruction
failure of peristalsis
no mechanical cause

Question 23

differences in presentation of SBO and LBO

Answer 23

SBO: vom occurs earlier, distention is less and pain higher in the abdomen

Question 24

AXR SBO

Answer 24

central gas shadows and no gas in large bowel

Question 25

AXR LBO

Answer 25

pain is more constant, peripheral gas shadows proximal to blockage, but not in rectum

(unless you’ve done a PR examination!)

Question 26

ileus obstruction

Answer 26

functional obstruction from reduced bowel motility

no pain + bowel sounds are absent

Question 27

simple obstruction

Answer 27

1 obstructing point

no vascular compromise

Question 28

closed loop obstruction

Answer 28

obstruction at 2 points

loop of grossly distended bowel at risk of perforation

Question 29

strangulated obstruction

Answer 29

blood supply is compromised

peritonism is the cardinal sign
other signs of mesenteric ischamia

Question 30

which types require surgery?

Answer 30

strangulation
closed loop

LBO

Question 31

which types can be managed conservatively? (initially)

Answer 31

incomplete SBO

ileus

Question 32

AXR with ‘inverted U’ loop of bowel that looks like a coffee bean

Answer 32

sigmoid volvulus

severe, rapid, strangulated obstruction

elderly, constipated + morbid pt

Question 33

laparotomy

Answer 33

surgical procedure involving a large incision through the abdominal wall to gain access into the abdominal cavity. It is also known as a celiotomy.