emergency approach & management of small bowel obstruction

1. SMALL BOWEL
OBSTRUCTION
Dr abdul rub
Pgy3 mem

2. OVERVIEW
:
•CLASSIFICATION
•COMMON CAUSES OF OBSTRUCTION
•CLINICAL FEATURES
•INVESTIGATION
•TREATMENT

3. What are our objectives?
we should be able to address the following questions
1. Is this bowel obstruction or ileus?
2. What is my immediate treatment plan?
3. Is this a small or large bowel obstruction?
4. Is this proximal or distal obstruction?
5. What is the cause of this obstruction?
6. Is this a complex or simple obstruction?
7. How should I start investigating my patient?
8. What is the role of other supportive investigations?
9. What are the indications for surgery?

4. 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 as physical barrier
the progression of gut contents
Ileus :is a paralytic or functional variety of
obstruction
Obstruction is: Partial or complete
Dynamic or a dynamic
Simple or strangulated

5. CAUSES OF I.OCAUSES OF I.O
(DYNAMIC)(DYNAMIC)

6. Patho-physiology I
 8L of isotonic fluid received by the small intestines
(saliva, stomach, duodenum, pancreas and hepatobiliary )
 6L 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
 Enteric bacteria consist of coliforms, anaerobes and
strep.faecalis.
 Normal intestinal mucosa has a significant immune role
 Distension results from gas and/ or fluid and can exert
hydrostatic pressure.
 In case of BO Bacterial overgrowth can be rapid
 If mucosal barrier is breached it may result in translocation of
bacteria and toxins resulting in bactaeremia, septaecemia and
toxaemia.

7. CLINICAL FEATURESCLINICAL FEATURES
High small bowel obstruction
vomiting occurs early and is profuse with rapid
dehydration.
Distension is minimal with little evidence of fluid levels on
abdominal radiography
Low small bowel obstruction
pain is predominant with central distension.
Vomiting is delayed.
Multiple central fluid levels are seen on radiography
Large bowel obstruction
distension is early and pronounced.
Pain is mild and vomiting and dehydration are late.
The proximal colon and caecum are distended on
abdominal radiography
CARDINAL
FEATURES:
Colicky pain
Vomiting
Abd distention
Constipation
OTHER FEATURES:
Dehydration
Hypokalaemia
Pyrexia
Abd tenderness

8. Clinical Findings
2. Examination
General
•Vital signs:
P, BP, RR, T, Sat
•dehydration
•Anaemia, jaundice,
LN
•Assessment of
vomitus if possible
•Full lung and heart
examination
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
Others
Systemic examination
If deemed necessary.
•CNS
•Vascular
•Gynaecological
•muscuoloskeltal

9. How to initially investigate
your patient
• Lab:
• CBC (leukocytosis, anaemia, hematocrit, platelets)
• Clotting profile
• Arterial blood gasses
• U& Crt, Na, K, Amylase, LFT and glucose, LDH
• Group and save (x-match if needed)
• Optional (ESR, CRP, Hepatitis profile
• Radiological:
• Plain xrays
• USS ( free fluid, masses, mucosal folds, pattern of paristalsis,
Doppler of mesenteric vasulature, solid organs)
• Other advanced studies (CT, MRI, Contrast studies……senior
decision)
• ECG and other investigations for co-morbid factors

10. Diagnosis

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

12. The Difference between small and large
bowel obstruction
Large bowel Small Bowel
•Peripheral ( diameter 6 cm max)
•Presence of haustration
•Central ( diameter 3 cm max)
•Vulvulae coniventae
•Ileum: may appear tubeless

13. Fluid levels with gas above;
‘stepladder pattern’. Ileal
obstruction by adhesions; patient
erect.
Supine radiograph from a patient with
complete small bowel obstruction
shows distended small bowel loops in
the central abdomen with prominent
valvulae conniventes (small white
arrow)
Figure 3. Lateral decubitus view
of the abdomen, showing air-fluid
levels consistent with intestinal
obstruction (arro ws).

14. 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 alergy to iodine • Figure: Axial computed tomography scan showing dilated,
contrast-filled loops of bowel on the patient’s left (yellow
arrows), with decompressed distal small bowel on the patient’s
right (red arrows). The cause of obstruction, an incarcerated
umbilical hernia, can also be seen (green arrow), with
proximally dilated bowel entering the hernia and
decompressed bowel exiting the hernia.
Source: Jackson, PG. & Raiji M., Evaluation and Management of Intestinal Obstruction, January 2011, American Academy of Family Physicians

15. Small Bowel Adhesions
• Accounts for 60-70% of All SBO
• Results from peritoneal injury, platelet activation and fibrin
formation.
• Associated with starch covered gloves, intraperitoneal sepsis,
haemorrhage and wash with irritant solutions iodine and other
foreign bodies.
• 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
• Patients with complex bands are more likely to be readmitted
• Readmission in surgically treated patients is 35%

16. TREATMENT OF ADHESIVE
OBSTRUCTION
Initially treat conservatively provided there is no signs of
strangulation; should rarely continue conservative treatment for
longer than 72 hours
At operation, divide only the causative adhesion and limit
dissection
Laparoscopic adhesiolysis in cases of chronic subacute
obstruction

17. HERNIA
• ACCOUNTS FOR 20% OF SBO
• COMMONEST 1. FEMORAL HERNIA
2. ID INGUINAL
3. UMBILICAL
4. OTHERS: INCISIONAL
• THE 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 ARTERIALC OMPROMISE.
• ATTEMPT TO DISTINGUISH THE DIFFERENCE BETWEEN:
• INCARCERATION
• SLIDING
• OBSTRUCTION
• STRANGULATION IS NOTED BY:
• PERSISTENT PAIN
• DISCOLOURATION
• TENDERNESS
• CONSTITUTIONAL SYMPTOMS

18. Volvulus
A twisting or axial rotation of a portion
of bowel about its mesentery. When
complete it forms a closed loop
obstruction ischemia
Can be primary or secondary:
 1°: congenital malformation of the gut
(e.g: volvulus neonatorum, cecal or sigmoid
volvulus)
 2°: more common, due to rotation of a piece of
bowel around an acquired adhesion or stoma
Commonest spontaneous type in adult
is sigmoid, can be relieved by
decompression per anum
Surgery is required to prevent or relieve
ischaemia
Features: palpable tympanic lump
(sausage shape) in the midline or left
side of abdomen.
Constipation, abdominal distension
(early & progressive)

19. Acute intussusceptionAcute intussusception
Occurs when one portion of the gut
becomes invaginated within an
immediately adjacent segment.
Common in 1st
year of life
Common after viral illness
enlargement of Peyer’s patches
Ileocolic is the commonest variety in
child.
Colocolic intussusception commonest
in adult
An intussusception is
composed of three parts :
the entering or inner tube;
the returning or middle
tube;
the sheath or outer tube
(intussuscipiens).

20. Classically, a previously healthy infant
presents with colicky pain and vomiting
(milk then bile).
Between episodes the child initially
appears well.
Later, they may pass a ‘redcurrant jelly’
stool.
Red currant jelly
stools

21. Acute Mesenteric Occlusion
• Acute ischemic of mesenteric vessel. Commonly SMA
• Causes: AF, mural thrombosis, atheromatous plaque from aortic aneurysm and valave
vegetation from endocarditis
• Features: -Sudden onset of severe abd. pain in pt with AF and atherosclerosis
-Persistent vomiting and defecation then passage of altered blood
-Hypovolumic shock
• Investigations: - Neutrophil leukocytosis
- Abd Xray: Absence of gas in thickened small intestines
• Treatment: - Anti-coagulant
- Embolectomy
- Revascularization
- Colectomy

22. PARALYTIC ILEUS
A state in which there is a failure of transmission of peristaltic waves 2° to
neuromuscular failure ( in Auerbach’s and Meissner’s plexuses)
Stasis  leads to accumulation of fluid and gas within bowel a/w distension,
vomiting, absence of bowel sound and absolute constipation
Varieties factors: postoperative, infection, reflex ileus and metabolic
Radiological: gas filled loops of intestines with multiple fluid levels

23. Ileus
• Associated with the following conditions:
• 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
• Metabolic abnormalities:
• Hypokalaemia
• Hyponatremia
• Uraemia
• Hypomagnesemia
• Bed ridden
• Drug induced: morphine, tricyclic antidepressants

24. 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

25. Management:
Essence of treatment prevention with use of nasogastric suction and
restriction of oral intake until bowel sound and passage of flatus return
Maintain electrolyte balance
Specific treatment:
• Removed primary cause
• Decompressed GI distension
• If prolong paralytic ileus , consider laparotomy exclude hidden cause and
facilitate bowel decompression

26. Small intestinal pseudo-obstruction Colonic pseudo-obstruction (Ogilvie’s
syndrome, )
This condition may be primary (i.e. idiopathic
or associated with
familial visceral myopathy) or secondary.
The clinical picture consists of recurrent
subacute obstruction.
 The diagnosis is made by the exclusion of a
mechanical cause.
Treatment consists of
initial correction of any underlying disorder.
Metoclopramide and
erythromycin may be of use.
This may occur in an acute or a chronic form.
presents as acute large bowel
obstruction.
Abdominal radiographs show evidence of
colonic obstruction, with marked caecal
distension being a common
feature.
AXR shows colonic obstruction with marked
caecal distension
Confirmation of absence mechanical cause
by colonoscopy or single contrast water
soluble barium enema or CT.
Once confirmed, treated by colonoscopic
decompression

27. Initial Management in the ER
• Resuscitate:
• Air way (O2 60-100%)
• Insert 2 lines if necessary
• IVF : Crytloids at least 120 ml/h. (determined by estimated fluid loss and
cardiac function). Add K+
at 1mmmol/kg
• Draw blood for lab investigations
• Inform a senior member in the team.
• NPO.
• Decompress with Naso-gastric tube and secure in position
• Insert a urinary catheter (hourly urinary measurements) and start a fluid input
/ output chart
• Intravenous antibiotics (no clear evidence)
• If concerns exist about fluid overloading a central line should be inserted
• Follow-up lab results and correction of electrolyte imbalance
• The patient should be nursed in intermediate care
• Rectal tubes should only be used in Sigmoid volvulus.

28. Source: Jackson, PG. & Raiji M., Evaluation and Management of Intestinal Obstruction, January 2011, American Academy of Family Physicians

29. INDICATIONS FOR SURGERY
• Absolute
– Generalised peritonitis
– Localised peritonitis
– Visceral perforation
– Irreducible hernia
• Relative
– Palpable mass lesion
– 'Virgin' abdomen
– Failure to improve
• Trial of conservatism
– Incomplete obstruction
– Previous surgery
– Advanced malignancy
– Diagnostic doubt - possible ileus
Source: http: Surgical Tutor.co.uk

30. Indications for Surgery
Immediate intervention:
• Evidence of strangulation (hernia….etc)
• Signs of peritonitis resulting from perforation or ischemia
In the next 24-48 hours
• Clear indication of no resolution of obstruction ( Clinical,
radiological).
• Diagnosis is unclear in a virgin abdomen
Intermediate stage
The cause has been diagnosed and the patient is stabalised

31. THANKS
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