Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Y4 Gastrointestinal > Obstruction > Flashcards

Obstruction Flashcards

1
Q

What do the presenting features of (SB & LB) GI tract obstruction depend on ?

A

The level of obstruction within the GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 2 main classification of obstruction ?

A
  1. Small bowel obstruction
  2. Large bowel obstruction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the cardinal features of any GI obstruction?

A
  1. Vomiting
  2. Pain
  3. Constipation - this may be incomplete (still some passage of faeces or flatus) or complete (no passage of either)
  4. Abdo distension - hear active ‘tinkling’ bowel sounds if mechanical obstruction +/- a mass may be palpable. On percussion abdo may be ressonant
  • Borborygmi (rumbling or gurgling noise made by the movement of fluid and gas in the intestines.)
  • May also have anorexia (WL)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the general physcial signs of obstruction ?

A
  • Dehydration (dry mouth, loss of skin turgor and elasticity)
  • Abdominal distension
  • Visible peristalsis
  • Relative lack of abdominal tenderness (obstruction with tenderness may indicate bowel strangulation)
  • Obstructing abdominal mass may be palpable
  • On percussion the centre of the abdomen tends to be resonant due to gaseous distension
  • Groins must be examined for an obstructing hernia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the characterisitc features of a small bowel obstruction rather than a large bowel obstruction ?

A

Small bowel obstruction:

  • Vomiting occurs earlier (within hours) and is of large volume (gastric, pancreatic, biliary secretions)
  • Distension is less marked and pain is colicky in nature and experienced centrally and higher in the abdomen
  • AXR will show central gas shadows with valvulae conniventes (folds of small intestine) that cross SB lumen & no gas will be seen in the large bowel/ distal from blockage site
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the characterisitc features of a large bowel obstruction rather than a small bowel obstruction ?

A
  • Pain is more constant and lower down
  • If ileocaecal valve stays shut (in 50% of cases) i.e. no reflux, pain may be felt over a distended caecum
  • Vomiting is faeculent and more gradual onset
  • AXR shows peripheral gas shadows (LB always peripheral & SB always central) proximal to the blockage. Haustra do not cross the whole lumen of LB
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The nature of vomiting gives a clue to where the obstruction is, what would the vomiting be like in the following obstruction types:

  1. Gastric outlet obstruction
  2. Upper SB obstruction
  3. Distal SB/LB obstruction
A
  1. Gastric outlet obstruction ==> semi-digested food (no bile)
  2. Upper SB obstruction ==> copious bile stained food
  3. Distal SB/LB obstruction ==> thicker brown, foul-smelling vomitius (faeculuent)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the classical sounds heard of ascultation of bowel obstruction ?

A
  • Bowel sounds are traditionally described as high-pitched and tinkling.
  • In practice they may be absent at the time of auscultation, echoing (cavernous quality), or may sound like water lapping against a boat.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

If the bowel obstruction is incomplete what happens ?

A

The clinical features may be less clearly defined.

  • Vomiting may be intermittent and bowel habit erratic.
  • Pain is more colicky in nature compared to complete obstruciton
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

No passage of flatus or faeces is pathognomic for what ?

A

Bowel obstruction (complete)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the most useful 1st line investigation for bowel obstruction ?

A

Supine AXR (also get an exerect CXR to rule out perforation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What else should you do for someone with osbtruction as part of the initial investigations ?

A
  • PR exam
  • Exam for hernias
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the 2nd line investigation after AXR has identified bowel obstruction ?

A
  • Contrast CT
  • Oral gastrograffin studies may be done also (if gastrograffin present in colon within 24hrs then obstruction is likely to resolve with just conservative measures)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the inital management of someone with bowel obstruction ?

A
  • Nil by mouth.
  • Insert IV cannula and send bloods (FBC, LFT’s, Bone group, Us & Es, amylase)
  • Blood gases
  • Resuscitate with IV fluids with hartmans or saline, replacing electrolyte losses.
  • Pass a NG tube (ryles not a feeding tube) to decompress the stomach.

Think ‘drip & suck’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How long do you drip and suck someone with bowel obstruction?

A

Can’t drip and suck hernias and expect resolution. Only adhesional

Up to 72 hours is standard

Intervene earlier if:

  • Strangulation
  • Perforation
  • Ischaemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ignoring the site of obstruction what are the 3 different types of GI obstruction ?

A
  1. Simple = one obstructing point, no vascular compromise
  2. Closed loop = obstruction at 2 points forming a loop of grossly distended bowel at risk of perforation. Needs urgent decompression
  3. Stragulated = blood supply compromised, patient is more ill than you would expect (sharper more constant pain), peritonism and other signs of mesenteric ischaemia
17
Q

What are the 2 main causes of small bowel obstruction ?

A
  1. Adhesions - congenital or after surgery
  2. Hernias
18
Q

What are the 4 main causes of large bowel obstruction ?

A
  1. Colon cancer
  2. Constipation/ bolus obstruction
  3. Diverticular stricture
  4. Volvulus - sigmoid or caecal
19
Q

List some of the rarer causes of bowel obstruction

A
  • Crohns stricture
  • Gallstone ileus
  • Intussusception
  • TB
  • Foreign body
20
Q

What are the 4 different causes of bolus obstruction ?

A
  1. Food bolus
  2. Impacted faeces
  3. Impacted ‘gallstone ileus’ (rare)
  4. Trichobezoar (rare) - hairball
21
Q

What does pain over a hernia indicate ?

A

That it is a strangulated hernia

22
Q

What is shown in the AXR?

A

Sigmoid volvulus

23
Q

Just to look at and differentiate from a sigmoid volvulus

A
24
Q

What are the 2 types of non-mechanical bowel obstruction ?

A
  1. Paralytic ileus
  2. Pseudo-obstruction
25
Q

Describe what paralytic ileus is and its risk factors

A

Disruption of the normal propulsive activity (adynamic bowel) of the GI tract, due to failure of peristalsis.

Risk factors:

  • Recent GI surgery
  • Any inflammation with localised peritonitis e.g. pancreatitis
  • Diabetic keto acidosis
  • Drugs e.g. TCA’s
26
Q

What are the signs/symptoms of paralytic ileus and its management ?

A
  • Symptoms and signs: similar to bowel obstruction although pain and high pitched bowel sounds are less common.
  • Treatment: ‘drip and suck’ while awaiting restoration of peristalsis.
27
Q

What is pseudo-obstruction (Ogilvie’s syndrome)?

A

Acute dilatation of the colon in the absence of colonic obstruction in acutely unwell patients. - it is like mechanical obstruction but with no cause found

Associated with:

  • Hip replacement surgery
  • Coronary Artery Bypass Grafts
  • Spinal #
  • Pneumonia
  • Frail / elderly patients
28
Q

What is the typical presenting features of pseudo-obstruction ?

A

Features are similar to that of mechanical obstruction

29
Q

How is pseudo-obstruction diagnosed ?

A

AXR +/- CT confirms gaseous distension to distal rectum

30
Q

What is the treatment of pseudo-obstruction ?

A

Neostigime or colonoscopic decompression if distension is causing pain or respiratory compromise

31
Q

Describe what constipation is

A

A common primary functional disorder of the bowel but may, of course, develop secondary to another condition. It may be defined as defecation that is unsatisfactory because of infrequent stools (< 3 times weekly), difficult stool passage (with straining or discomfort), or seemingly incomplete defecation.

32
Q

What are the clinical features of constipation ?

A
  • The passage of infrequent hard stools
  • Sensation of incomplete evacuation
  • Manual manoeuvers needs to facilitate evaucation
33
Q

What are the risk factors for constipation ?

A
  • Mainly poor diet & exercise, laxative abuse, old-age, opioids,
  • Motility disorders
34
Q

What is the treatment of constipation ?

A
  • 1st line = reassurance - encourage drinking more, diet & excercise - high fibre diet
  • 2nd line = simulant (bisacodyl or senna) + bulking agent (bran powder or isphagulha husk) OR just an osmotic laxative e.g. lactulose
  • 3rd line = enema

Y4 Gastrointestinal (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions