Obstruction Flashcards
1
Q
What can obstruction be
A
Complete (complete constipation)
Incomplete (passage flatus / stool 6-12 hours after symptom onset)
Simple = no interference with blood supply
Exntrinsic / extra-mural
Intramural
Intraluminal
2
Q
What are common causes of large bowel obstruction
A
Colon cancer (60%)
Diverticulitis causing post infective stricture (20%)
Volvulus (5%)
Impacted stool
3
Q
What are other structural causes
A
IBD stricture
Hernia
Adhesions - surgery / peritonitis / intra-abdo infection
4
Q
What is an ileus
A
Temporary obstruction due to decreased motility / absence of peristaltic contractions
Will have no bowel sounds as no movement
5
Q
What causes ileus
A
Post-surgery Infections Electrolyte imbalances - hyponatraemia Trauma Drugs Pancreatitis Peritonitis
6
Q
What is Pseudo-obstruction
A
Resembles mechanical but no lesion
7
Q
What can cause pseudo obstruction
A
Parkinson's MS Nerve issue Hypothyroid Hirschprungs Meconium ileus (CF) Ogilvies
8
Q
What is Olgivies and what puts you at risk
A
Obstruction
Raised WCC
Fever
Pelvic surgery / trauma / CVS and near disease
9
Q
How does obstruction present
A
Severe pain Abdo distension Diarrhoea early as increased peristalsis Constipation - absolute in distal but less pronounced if high Nausea Vomitnig = late sign Decreased appetite / anorexia Borborygmi High pitched bowel if early Silent abdomen if peritonitis Signs of dehydration / shock Altered bowel PR bleed
10
Q
What does intermittent obstruction suggest
A
Volvulus
11
Q
What puts you at increased risk of obstruction
A
Malignancy
Surgery
12
Q
How do you Dx obstruction
A
Bloods
DRE
AXR = key in bowel obstruction
CT abdo = definite
13
Q
What bloods
A
FBC U+E LFT Amylase as abode pain ABG or VBG shows clinical status
14
Q
What will AXR show
A
Dilated bowel loops
Free air under diaphragm if perforates
Haustra 1/3 accross
15
Q
What do you use to get cause
A
CT
16
Q
What are other useful tests
A
Gastograffin + AXR to look for perforation / anastomotic leak USS Air or barium enema Colonoscopy CT iconography if unfit
17
Q
When do you caution with colonoscopy
A
May perforation / distension worse
Used to untwist volvulus before surgery
18
Q
How do you deal with obstruction
A
ABCDE NBM IV fluid NGT to remove food and prevent vomiting Pain relief Anti-emetic Catheter Enema Ax if aspiration Correct electrolyte abnormalities Surgery = definite
19
Q
Why can obstruction cause chest signs
A
Distended abdo presses on lungs
20
Q
What must you do if on NG tube or obstructed
A
Changes meds to IV or SC
21
Q
What is common cause of small bowel obstruction
A
Adhesions x
Hernia x
Stricture - IBD / radiation
Malignancy
22
Q
When are adhesions common
A
Post - surgery
Sepsis
Peritonoitis
Haemorrhage
23
Q
What are other causes
A
RT Intussception Ischaemia Gallstone ileus Paralytic ileus Foreign body TB
24
Q
How does small bowel obstruction present
A
Same Tend to have vomiting earlier Pain higher in abdo Distension less Central distension and increases as lower down Distension in flanks if colonic
25
What is important when looking at vomit
Bile = suggest past gall bladder
Bright green = proximal
Dark = distal
26
How do you Dx
AXR plays a key role in bowel obstruction
Gastrografin for level
CT abdo if unclear
27
What does AXR show in small bowel
Valvulae go all the way across
| Dilated bowel
28
What does CT show
Dilated loops of small bowel
29
What else is important
U+E
| ECG for electrolyte imbalance
30
Why is oxygen impaired
Distension
Ischaemia
Sepsis
31
What is general management
```
ABC
Oxygen
Analgesia
Correct hypovolaemia / electrolyte - IV fluid
NG to reduce distension
NBM
```
32
What should you do regular
Assess fluid
33
What should you always do if vomiting
Abdo exam
| Check for hernia
34
Complications of small bowel obstruction
```
Inection
Sepsis
Necorsis
Hypovolaemia
3rd space fluid loss
Shock
Increased hydrostatic pressure = oedema and ischaemia
Increased mucosal permeability
Fluid and Electrolyte disturbances
Dehydration leading to AKI
Renal failure
Stragnualtion
Peritonitis
Perforation
```
35
What does dehydration cause
AKI
36
What is strangulation
Intestinal obstruction with persistent interference of blood supply
37
What causes strangulation
```
Hernia
Intussception
Intestinal obstruction
Volvulus
Vascular occlusions
```
38
What does internal strangulated hernia cause
```
Pain more severe than you'd expect
Never goes between attacks
Peritonism = cardinal sign
Shcok
Localised tenderness and rebound
NG fails to relieve
```
39
What does external strangulated hernia cause
Tense
Tender
Irreducible
No expansible impulse
40
What causes intussception in adult
Polyp
Lipoma
Adhesions
Malignant tumour
41
How do you Dx and Rx
Target sign on USS
| Laparotomy and resection
42
When is paralytic ileus common
Post-surgery
Drug
Electrolyte
43
What suggest ileus and how do you Rx
```
Lack of bowel sounds
N+V
Distension
Abdo tenderness
Dilated loops of bowel
Previous surgery now no bowel sounds
Fluid and electrolyte on bloods
```
Rx = NBM, NG tube, start IV fluid and recommence oral slowly
Mobilise to stimulate
TPN if long term
44
What are complications of strangulation
```
Bowel ishcaemia
Gangrene
Perforation
Peritonitis
Sepsis
Hypovolaemic shock
Dehydration
```
45
What is best nutrition
Going through gut is always best
| Try most natural
46
When might enteral or parenteral nutrition be needed
Severe vomitnig or obstruction
47
What does TPN require
Daily bloods - U+E
| PICC or peripheral
48
Complications of TPN
```
Infection
Refeeding
Fluid balance
Phlebitis / thrombosis
Sepsis
Abnormal LFT
```
49
How do you decrease risk of abnormal LFT
Lipid free days
Decreased duration
Altered content of bags but only do this in chronic
Watch glucose as liver may not cope
50
What type of jaundice does TPN cause
Painless
| Non-obstructive
51
What is dioralyte used for
Dehydration and to increase salt content i.e. if high volume fistula / stoma
Pulls out electrolytes
52
What is NG tube used for
Gastric outlet obstruction
| Pseudo-obstrution / ileus
53
What is refeeding syndrome
Body switching from catabolism to carb when food introduced
54
What does it cause
```
Low phosphate
Low K
Low Mg
Low B12
Abnormal fluid
Organ failure
```
55
What can low Mg cause
Torsade de points
56
How do you treat
Slow introduction
57
Who is high risk
```
Low BMI
Weight loss
Poor intake
Metabolic disturbance prior
Alcohol
```
58
What occurs above obstruction
Peristalsis and distension
| Increases the higher up
59
What can occur at level
Perforation
60
What occurs below obstruction
Immobile and pale bowel
61
What type of distension if jejunal
Minimal
62
Distension in ileal
Central
63
Distension in colonic
Central
| Flanks - colonic only
64
When would obstruction present without constipation
Hernia
Pelvic abscess
Mesenteric vascular occlusion
65
What do you do in examination
```
Look for scars - adhesions?
Hernia
PR
Palpation
Ausculate
```
66
What do you hear on auscultation
Loud and high pitched in early
| Silent if peritonitis
67
What may erect CXR show
Free air if late perforation
68
How much dilatation in SBO
>3cm
69
Does normal AXR exclude
No
70
Summary high SBO
Early vomiting
Minimal distension
Minimal small bowel loops
71
Summary low SBO
Late vomitng
Pain and distension
Dilated loops
72
Symmary LBO
Lots of distension
| Pain and vomit late
73
What confirms the Dx of bowel obstruction
CT
74
What is CT good for
Determining level
Find cause
Detecting ischaemia and perforation
75
What will confirm resolution of SBO
Contrast in caecum in gastrograffin
76
What always has absent bowel
Paralytic as no movement
77
What is Olgivie associated with
```
Elderly
Recent surgery
Infection - WCC / fever
Severe pulmonary / CV disease
Severe electrolyte imabalnce
Drugs
```
78
How can you get hypovolaemic -> AKI but have overall +ve fluid balance
Fluid lost into 3rd space
79
In obstruction what occurs before signs
Fluid an electrolyte dsiturbance
| Hypovolaemia
80
What is a volvulus
Bowel twist abnormally
81
Where does it occur
Sigmoid
| Can occur in caecal
82
What are RF
```
Psychiatric disorder
Neuro disorder
Nursing home
Chronic constipation
Pelvic mass
Adhesion
```
83
How does it present
Colicky pain
Constipation
Distension - asymmetric
Tender
84
What are complications
Obstruction
Ischaemia
Perforation
85
How do you Dx
Presents like obstruction
AXR - coffee bean sign
CT to confirm
86
How do you Rx
Endoscopy decompression
Laparotomy
- Hartmann's for sigmoid
- R-hemi-Colectomy for caecal
87
What is an incisional hernia
Hernia that occurs at site of incision due to inadequate closure
88
What increases risk
Bigger incision = bigger risk
| Comorbid which cause poor heeling
89
To Dx obstruction what is used
Will get AXR as quick
- Good for toxic megacolon
Almost always CT to define location
90
What are other measures in obstruction
Octeoride as reduces gastric secretion and associated N+V
| Steroid as stimulates bowel but can cause increased hunger when want NBM
