gut obstruction

1. INTESTINAL
OBSTRUCTION
Methas Arunnart MD.

2. The common Scenario
A 50 year old gentleman presents
with abdominal pain, distension and
absolute constipation. With
repeated episodes of vomiting.
His vital sign were stable, abdomen
distended with diffuse tenderness
but minimal peritonism. Bowel
Sounds are hyperactive.
The plain abdominal xray was taken
on admission.

3. Introduction and Definitions
Accounts for 5% of all acute surgical admissions
Patients are often extremely ill requiring prompt
assessment, resuscitation and intensive monitoring
Obstruction A mechanical blockage arising from a
structural abnormality that presents a
physical barrier to the progression of gut
contents.
Ileus is a paralytic or functional variety of
obstruction

4. Patho-physiology I
 8L of isotonic fluid received by the small
intestines (saliva, stomach, duodenum,
pancreas and hepatobiliary )
 7L absorbed
 2L enter the large intestine and 200 ml excreted
in the faeces
 Air in the bowel results from swallowed air ( O2
& N2) and bacterial fermentation in the colon (
H2, Methane & CO2), 600 ml of flatus is released
 If mucosal barrier is breached it may
result in translocation of bacteria and
toxins resulting in bactaeremia,
septaecemia and toxaemia.

5. Patho-physiology II
Obstruction results in:
1. Initial overcoming of the obstruction by
increased paristalsis
2. Increased intraluminal pressure
3. Vomiting
4. Lymphatic and venous congestion resulting
in edematous tissues
5. sequestration of fluid into the lumen from the
surrounding circulation
6. Factors 3,4,5 result in hypovolaemia and
electrolyte imbalance
7. Further: localised anoxia, mucosal depletion
necrosis and perforation and peritonitis.
8. Bacterial over growth with translocation of
bacteria and it’s toxins causing bacteraemia
and septicaemia.

6. HOW TO
APPROACH?

7. WHAT ARE YOUR OBJECTIVES?
You should be able to address these questions
1. Is this bowel obstruction?
2. Partial or complete obstruction?
3. Site of obstruction?
4. Cause of this obstruction?
5. Is this a complicated or simple obstruction?

8. 1. IS THIS BOWEL
OBSTRUCTION?

9. The Universal Features
Colicky abdominal pain
Vomiting
Constipation/obstipation
Abdominal distension.
Clinical Findings
1. History

10. Clinical Findings
2. Examination
Others
Systemic examination
If deemed necessary.
•CNS
•Vascular
•Gynaecological
•muscuoloskeltal
Abdominal
•Abdominal
distension and it’s
pattern
•Hernial orifices
•Visible peristalsis
•Cecal distension
•Tenderness,
guarding and
rebound
•Organomegaly
•Bowel sounds
–High pitched
–Absent
•Rectal examination
General
•Vital signs:
P, BP, RR, T, Sat
•dehydration
•Anaemia, jaundice,
LN
•Assessment of
vomitus if possible
•Full lung and heart
examination

11. Radiological Evaluation
Normal Scout
Always request:
Supine, Upright and CXR
Gas pattern:
 Gastric,
 Colonic and 1-2 small bowel
Check gasses in 4 areas:
1. Caecal
2. Hepatobiliary
3. Free gas under diaphragm
4. Rectum
Look for calcification,soft tissue masses,
psoas shadow
Look for fecal pattern

12. X-ray finding
 Different height in
the same loop
 Step ladder pattern

13. Ileus
 Associated with the following conditions:
 Metabolic abnormalities:
 Hypokalaemia
 Hyponatremia
 Uraemia
 Hypomagnesemia
 Postoperative and bowel resection
 Intraperitoneal infection or inflammation
 Ischemia
 Extra-abdominal: Chest infection, Myocardia infarction
 Endocrine: hypothyroidism, diabetes
 Spinal and pelvic fractures
 Retro-peritoneal haematoma
 Bed ridden
 Drug induced: morphine, tricyclic antidepressants

14. Is this an ileus or obstruction
Clinical features
 Is there an under lying cause?
 Is the abdomen distended but tenderness is not marked.
 Is the bowel sounds diffusely hypoactive.
Radiological features:
 Is the bowel diffusely distended
 Is there gas in the rectum
 Are further investigasions (CT or Gastrografin studies)
helpful in showing an obstruction.
Does the patient improve on conservative measures

15. Example of ileus

16. 2.PARTIAL OR
COMPLETE
OBSTRUCTION?

18. 3. SITE OF
OBSTRUCTION?

19. Clinical Findings
 Persistent pain may be a sign of strangulation
 Relative and absolute constipation
Colonic
•? Preexisting change
in bowel habit
•Colicky in the lower
abdomin
•Vomiting is late
•Distension prominent
•Cecum ? distended
Distal small bowel
•Pain: central and
colicky
•Vomitus is feculunt
•Distension is severe
•Visible peristalsis
•May continue to pass
flatus and feacus
before absolute
constipation
High
•Pain is rapid
•Vomiting copious and
contains bile jejunal
content
•Abdominal distension
is limited or localized
•Rapid dehydration

20. The Difference between small
and large bowel obstruction
Small BowelLarge bowel
•Central ( diameter 5 cm max)
•Vulvulae coniventae
•Ileum: may appear tubeless
•Peripheral ( diameter 8 cm max)
•Presence of haustration

21. 4. CAUSE OF
OBSTRUCTION?
Small bowel VS Large bowel obstruction

22. Causes- Small Bowel
ExtraluminalMuralLuminal
Postoperative
adhesions
Congenital
adhesions
Hernia
Volvulus
Neoplasm
lymphoma
carcinoid
carinoma
lipoma
polyps
leiyomayoma
hematoma
secondary Tumors
TB
Crohns
Stricture
Intussusception
Congenital
F. Body
Bezoars
Gall stone
Food Particles
A. lumbricoides

23. Small Bowel Adhesions
 Accounts for 60-70% of All SBO
 Results from peritoneal injury, platelet activation
and fibrin formation.
 As early as 4 weeks post laparotomy. The majority
of patients present between 1-5 years
 Colorectal Surgery 25%
 Gynaecological 20%
 Appendectomy 14%
 70% of patients had a single band
 Readmission in surgically treated patients is 35%

24. Hernia
 Accounts for 10% of SBO
 Commonest
1. Femoral hernia
2. ID inguinal
3. Umbilical
4. Others: incisional and internal H.
 Site of obstruction is the neck of hernia
 The compromised viscus is with in the sac.
 Ischaemia occurs initially by venous
occlusion, followed by oedema and arterial
compromise.

25. Hernia
 Followed by oedema and arterial compromise.
 Attempt to distinguish the difference between:
 Incaceration
 Sliding
 Obstruction
 Strangulation is noted by:
 Persistent pain
 Discolouration
 Tenderness
 Constitutional symptoms

26. Intussusecption
 Intussusception is an "internal prolapse" of the bowel
 This occurs when a mass or lead point in the bowel is
pulled forward by normal peristalsis
 Intussusception is rare in adults, 1-5% of SBO.
 Adult intussusception commonly involves a distinct
pathologic lead point, which is malignant in over half of the
cases.
 Pediatric intussusception is usually due to a benign etiology
and can usually be managed with non-operative reduction.

27. Intussusecption
 Symptoms are often chronic; intermittent abdominal pain is
the most common presentation in adults.
 The diagnosis is most often made with CT
 A "target sign" may be seen on CT on perpendicular view,
while the intussusception will appear as a sausage shaped
mass when the CT beam is parallel to the longitudinal axis.
 An increased incidence of intussusception has been
reported in patients with AIDS. This is due to the high
incidence of conditions, such as lymphoid hyperplasia,
Kaposi's sarcoma, and non-Hodgkin's lymphoma.

28. Intussuseption in CT

29. Other causes
IBDGall stone IleusIntussusception

30. Large Bowel Obstruction
Aetiology:
1. Carcinoma: The commonest cause, 18% of CA colon
present with obstruction
2. Benign stricture: Due to Diverticular disease, Ischemia,
Inflammatory bowel disease.
3. Volvulus: 1. Sigmoid Volvulus
2. Caecal Volvulus
4. Hernia:
5. Congenital : Hirschusbrung, anal stenosis and agenesis
•Distinguishing ileus from mechanical obstruction is challenging
•According to Leplac’s law: maximum pressure is at the it’s
maximum diameter. Cecum is at the greatest risk of perforation

31. Sigmoid Volvulus Colonic Obstruction

32. Sigmoid volvulus

33. Role of CT
 Used with iv contrast, oral and rectal contrast
(triple contrast).
 Able to demonstrate abnormality in the bowel wall,
mesentery, mesenteric vessels and peritoneum.
 It can define
 the level of obstruction
 The degree of obstruction
 The cause: volvulus, hernia, luminal and mural causes
 The degree of ischaemia
 Free fluid and gas
 Ensure: patient vitally stable with no renal failure and no
previous allergy to iodine

34. CT SCAN

35. Role of barium gastrografin
studies
 As: follow through, enema
 Limited use in the acute setting
 Gastrografin is used in acute
abdomen but is diluted
 Useful in recurrent and chronic
obstruction
 May able to define the level and
mural causes.
Barium should not be used in
a patient with peritonitis

36. 5. IS THIS A SIMPLE
OR COMPLICATED
OBSTRUCTION?

37. Who suspected complicated
obstruction?
Patients suspected on admission of having
complicated obstruction with
 complete or closed-loop obstruction
 patients with fever, leukocytosis, tachycardia,
metabolic acidosis
 continuous abdominal pain or peritonitis
 those who develop these signs and symptoms
during the course of nonoperative Mx.

38. Closed loop obstruction
 Small bowel  Large bowel

39. MANAGEMENT

40. INITIAL MANAGEMENT
The primary goals in the initial management of
patients with SBO are to determine:
 The degree of volume depletion and metabolic
derangement
 The severity, cause, extent and location of the
obstruction
 Whether nonoperative management can be
considered
 The need for and timing of operative intervention

41. INITIAL MANAGEMENT
 Adequate intravenous (IV) access should be
obtained for fluid resuscitation. should be given
until the patient makes urine or is clinically
euvolemic.
 A Foley catheter should be placed to monitor urine
output. If necessary, a central venous catheter or
Swan-Ganz catheter can be inserted
 Bowel decompression – NPO +NG tube insertion
 Antibiotics are not indicated in the routine.
Patients who indicate the need for surgery should
receive prophylactic antibiotics perioperatively.

42. OPERATIVE MANAGEMENT
 The timing of surgical intervention requires careful consideration.
Approximately one-quarter of patients admitted for small bowel obstruction
will require operation. Patients suspected on admission of having
complicated obstruction with complete or closed-loop obstruction, patients
with fever, leukocytosis, tachycardia, metabolic acidosis, continuous
abdominal pain or peritonitis, or those who develop these signs and
symptoms during the course of nonoperative management warrant prompt
surgical exploration [45]. Although prophylactic antibiotics are not routinely
administered for uncomplicated small bowel obstruction, antibiotics may be
warranted for patients with complications (eg, perforation) (table 2) [52-54].
 Every patient considered for exploration due to a suspected small bowel
obstruction, whether open or laparoscopically, should be appropriately
resuscitated prior to surgery with IV fluids and have their electrolytes
repleted, as indicated. This is especially important for patients with copious
emesis resulting from more proximal obstruction, obstruction lasting several
days, or obstruction causing large-volume intraluminal fluid sequestration.
These patients may have severe metabolic acidosis, volume depletion, and
electrolyte abnormalities, and need resuscitation prior to operation.