Small Bowel Obstruction

Front 1

How common are adhesions as a cause of SBO?

Back 1

most common cause 15-42%

Front 2

Difference in clinical presentation between a proximal and a distal SBO?

Back 2

proximal tend to present early (within a day)
Distal- more subacute, 2-3 day course (crampy abdo pain prior to vomiting, distension and constipation)
Bowel sounds initiallyu hyperactive and hight pitched and later reduced
hernias tend to present early and more acutely, neoplasm: slow, adhesions: intermediate

Front 3

What does colonic gas indicate in a small bowel obstruction?

Back 3

An incomplete obstruction or an adynamic ileus rather than a complete mechanical obstruction

Front 4

What are the signs of a small bowel obstruction on an AXR?

Back 4

Dilated loops of small bowel (>3cm)- disproportionate to more distant small bowel oe colon
Small bowel air fluid levels that exceed 2.5cm in length
Air fluid levels at different heights in the same loop
Small bybbles of gas trapped between folds in dilated, fluid filled loops

Front 5

What kind of contrast radiography is done for an SBO

Back 5

Use gastrograffin rather than barium
Also forms part of conservative management of SBO: gastrograffin is hyperosmolar and may stimulate peristalitic activity, as well as decreasing interstitial wall oedema
Caution in dehydrated patients as gastrograffin may exacerbate dehydration by sequestering third space fluid in GI lumen

Front 6

When is non-operative management of SBO appropriate

Back 6

No signs of intestinal strangulations on repeated eval of abdomen
If there has been no significant improvement for 48 hours operative management is generally indicated

Front 7

When is operative management indicated for a small bowel obstruction?

Back 7

Patients suspected of having complete or closed-loop obstruction with fever, leukocytosis, tachycardia, metabolic acidosis, continuous pain or peritonitis warrant prompt exploration
In patients being managed conservatively: If there is concern that the patient has increasing pain, distension and persistent high NG output, surgical exploration should be considered.
1/4 will eventiually require operation

Front 8

What kind of pain suggests bowel ischemia

Back 8

constant rather than intermittent pain

Front 9

Management of a closed loop bowel obstruction

Back 9

find loop and free it
assess viability
if necessary: place warm pack over bowel then re-examine several minutes later
if not viable: perform simple resection and primary anastomosis

Front 10

Recurrence rate after initial adhesiolysis after obstruction

Back 10

20%Manage recurrent obstructions non-operatively as much as possible (unless evidence of bowel compromise e.g. increasing pain, fever, leukocytosis, high NG output and increasing bowel dilatation on plain films)

Hint 10

May consider long intestinal tube through gastrostomy for three months- but incomplete evidence that this is effective

Front 11

When are post-op adhesions most extensive after a laparotomy?

Back 11

10-21 days

suspect SBO rather than ileus if bowel function absent >5d

Front 12

Management of post-operative ileus

Back 12

Strangulation is uncommon
Manage with careful observation: unless complete obstrucion, intra-abdominal sepsis
AXR. If diagnosis is uncertain- use dilure barium/gastrograffin follow-through to determine severity of obstruction/relieve the obstruction
consider parenteral nutrition if NBM > 7d

Front 13

Management of SBO caused by malignant metastases

Back 13

Rarely strangulate
Manage with low residue diet/NG decompression
If good prognosis- operative intervention with resection or bypass

Front 14

Management of SBO due to crohns

Back 14

Initially non-operative
steroids and metronidazole
surgery if persists
resect phlegmatous segment and manage fibrotic stricture with stricturoplasty

Front 15

Management of gallstone ileus

Back 15

usually >2.5cm,impacts 60cm from ileocecal valve- subacute SBO in elderly
will see gas in the biliary tree on AXR
At surgery: crush gallstone and empty into lg bowel/enterotomy
Leave gallbladder alone