2. Definitions
ā¢ Intestinal Obstruction: A mechanical blockage
arising from a structural abnormality that
presents a physical barrier to the progression
of gut contents.
ā¢ Partial or complete
ā¢ Simple or strangulated
ā¢ Ileus: is a paralytic or functional variety of
obstruction.
3. Patient Presentation
ā¢ A 50 year old gentleman presents with
abdominal pain, distension and absolute
constipation with repeated episodes of
vomiting.
ā¢ His vital sign were stable, abdomen distended
with diffuse tenderness but minimal
peritonism. Bowel Sounds are hyperactive.
4. Common Questions
ā¢ Is this bowel obstruction or ileus?
ā¢ Is this a small or large bowel obstruction?
ā¢ Is this proximal or distal obstruction?
ā¢ What is the cause of this obstruction?
ā¢ Is this a complex or simple obstruction?
ā¢ How should I start investigating my patient?
ā¢ What is the role of other supportive investigations?
ā¢ What is my immediate/ intermediate treatment plan?
ā¢ What are the indications for surgery?
5. Intestinal Physiology
ā¢ 8L of isotonic fluid received by the small intestines (saliva,
stomach, duodenum, pancreas and hepatobiliary )
ā¢ 6L re-absorbed
ā¢ 2L enter the large intestine and 200 ml excreted in the
faeces
ā¢ 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
ā¢ Enteric bacteria consist of coliforms, anaerobes and
strep.faecalis.
ā¢ Normal intestinal mucosa has a significant immune role
6. Pathological events
ā¢ Distension results from gas and/ or fluid and
can exert hydrostatic pressure.(Laplace Law)
ā¢ In case of Bowel Obstruction, Bacterial
overgrowth can be rapid
ā¢ If mucosal barrier is breached it may result in
translocation of bacteria and toxins resulting
in bactaeremia, septaecemia and toxaemia.
7. Pathological Basis of clinical events.
ā¢ Initial overcoming of the obstruction(CONSTIPATION) by increased
peristalsis(COLICKY ABDOMINAL PAIN)
ā¢ (ABDOMINAL DISTENTION) & (VOMITING)Increased intraluminal
pressure by fluid and gas, sequestration of fluid into the lumen from
the surrounding circulation
ā¢ Lymphatic and venous congestion resulting in edematous tissues
(TISSUE EDEMA).
ā¢ Vomiting result in hypovolemia and electrolyte imbalance (ILEUS).
ā¢ Further: anoxia, mucosal necrosis and perforation and
peritonitis.(COMPLICATIONS)
ā¢ Bacterial over growth with translocation of bacteria and itās toxins
causing bacteremia and septicemia.(SYSTEMIC SIGNS)
8. Principles of Management
SUCK & DRIP.
ā¢ Decompress with Naso-gatric Tube or Flatus Tube.
ā¢ Replace lost fluid in vomiting or 3rd space.
ā¢ Correct electrolyte abnormalities (Hypcholremic,
Hyopnatremic, Hypokalemic, metabolic Alkalosis)
ā¢ Recognize strangulation (Hernia) and perforation
(Peritonitis)
ā¢ Systemic antibiotics (Broad Spectrum).
9.
10. Causes of Small Bowel Obstruction.
ā¢ Luminal Causes:
ā¢ Foreign Body
ā¢ Bezoars
ā¢ Gall stone
ā¢ Food Particles
ā¢ Ascaris lumbricoides
12. Causes of Small Bowel Obstruction
Extra-mural:
ā¢ Postoperative adhesions.
ā¢ Congenital adhesions & Bands.
ā¢ Hernia (External & Internals, Incisional)
ā¢ Volvulus (Around base of Mesentery)
13. Small Bowel Adhesions
ā¢ Accounts for 60-70% of All Small Bowel Obstructions.
ā¢ Results from peritoneal injury, platelet activation and fibrin
formation.
ā¢ Associated with starch covered gloves, intraperitoneal sepsis,
haemorrhage and wash with irritant solutions iodine and other
foreign bodies.
ā¢ As early as 4 weeks post laparotomy. The majority of patients
present between 1-5 years
ā¢ Colorectal Surgery 25%
ā¢ Gynaecological 20%
ā¢ Appendectomy 14%
ā¢ 70% of patients had a single band
ā¢ Patients with complex bands are more likely to be readmitted
ā¢ Readmission in surgically treated patients is 35%
14. Hernias
ā¢ Accounts for 20% of SBO
ā¢ Commonest 1. Femoral hernia 2. ID inguinal 3.
Umbilical 4. Others: incisional and internal H.
ā¢ The site of obstruction is the neck of hernia
ā¢ The compromised viscus is with in the sac. Ischemia
occurs initially by venous occlusion, followed by edema
and arterial compromise.
ā¢ Attempt to distinguish the difference between:
ā¢ Incarceration, Sliding, Obstruction.
ā¢ Strangulation is noted by: Persistent pain,
Discoloration, Tenderness, Constitutional symptoms
15. Other Common causes of Small Bowel
Obstructions.
ā¢ Intussusception: part of the intestine has
invaginated into another section of intestine.
ā¢ Gall stone Ileus: caused by an impaction of a
gallstone within the lumen of the small
intestine. Which enters the gut lumen via
cholecysto-enteric fistula.
ā¢ Crohnās Disease:is a type of inflammatory
bowel disease (IBD)
16.
17. Large Bowel Obstruction
ā¢ Distinguishing ileus from mechanical
obstruction is challenging
ā¢ According to Laplace's law: maximum pressure
is at the itās maximum diameter. Cecum is at
the greatest risk of perforation
ā¢ Perforation results in the release of formed
feaces with heavy bacterial contamination
18. Causes of Large Bowel Obstructions.
ā¢ 1. Carcinoma: The commonest cause, 18% of colonic
carcinomas present with obstruction
ā¢ 2. Benign stricture: Due to Diverticular disease,
Ischemia, Inflammatory bowel disease.
ā¢ 3. Volvulus:
A. Sigmoid Volvulus: Results from long redundant,
faecaly loaded colon with a narrow pedicle
B. Caecal Volvulus
ā¢ 4. Hernia.
ā¢ 5.Congenital:Hirschusbrung, anal stenosis and agenesis
19. Diagnosis of Intestinal Obstruction
ā¢ Clinical Features:
Colicky Abdominal Pain, Absolute Constipation,
Vomiting & Abdominal Distension.
ā¢ Radiology:
Plain X-ray Films (Erect & Supine).
Contrast studies (Single & Double) Diagnostic as
well as therapeutic.
Ultrasound Scan & Doppler Studies.
CT Scan (Plain & Contrast).
MRI.
20. Other Investigations
ā¢ Hematological:
CBC, ESR, Electrolytes, Urea & Creatinine Levels,
LFTs, RFTs, Blood Glucose level, Serum Amylase
level, cultures etc.
ā¢ Pathological: Urine Analysis & Cultures, FNAC
or Biopsy for enlarged Lymph Nodes.
ā¢ Laparoscopic: Diagnostic as well as
therapeutic.
21.
22. Comparative Features in History
ā¢Colonic
ā¢ Pre-existing change in bowel habit
ā¢Colicky in the lower abdomen
ā¢Vomiting is late
ā¢Distension prominent
ā¢Cecum ? distended
ā¢Distal small bowel
ā¢Pain: central and colicky
ā¢Vomitus is feculent
ā¢Distension is severe
ā¢Visible peristalsis
ā¢May continue to pass flatus and feaces before absolute constipation
ā¢High
ā¢Pain is rapid
ā¢Vomiting copious and contains bile jejunal content
ā¢Abdominal distension is limited or localized
ā¢Rapid dehydration
23. Examination Findings
Abdominal
ā¢ Abdominal distension and itās
pattern
ā¢ Hernial orifices
ā¢ Visible peristalsis
ā¢ Cecal distension
ā¢ Tenderness, guarding and
rebound
ā¢ Organomegaly
ā¢ Bowel sounds
ā¢ High pitched
ā¢ Absent
ā¢ Rectal examination
General Examination
ā¢ Vital signs:
ā¢ P, BP, RR, T, Sat
ā¢ dehydration
ā¢ Anaemia, jaundice, LN
ā¢ Assessment of vomitus if
possible
ā¢ Full lung and heart
examination
ā¢ Systemic examination
If deemed necessary.
ā¢ CNS
ā¢ Vascular
ā¢ Gynaecological
ā¢ muscuoloskeltal
24. Radiological Evaluation
ā¢ Views: Supine, Erect and CXR
ā¢ Gas pattern: Gastric, Colonic and 1-2 small
bowel
ā¢ Fluid Levels: Gastric, 1-2 small bowel
ā¢ Check gasses in 4 areas: Caecal, Hepatobiliary,
Free gas under diaphragm, Rectum
ā¢ Look for soft tissue masses, psoas shadow
ā¢ Look for fecal pattern
25.
26. The Difference between small and
large bowel obstructionCentral ( diameter 5 cm max)
Vulvulae coniventae
Ileum: may appear tubeless
Peripheral ( diameter 8 cm max)
Presence of haustration
27. US Scan & Doppler Studies
ā¢ Free fluid,
ā¢ Abdominal Masses,
ā¢ Intestinal mucosal folds,
ā¢ Intestinal pattern of peristalsis,
ā¢ Doppler of mesenteric vasculature,
ā¢ Solid organs evaluation.
28.
29. Role of CT in Diagnosis
ā¢ Used with iv contrast, oral and rectal contrast
(triple contrast).
ā¢ Able to demonstrate abnormality in the bowel
wall, mesentery, mesenteric vessels and
peritoneum.
ā¢ Ensure: patient vitally stable with no renal
failure and no previous allergy to iodine.
30. Findings on CT Scan Abdomen
It can define
ā¢ the level of obstruction
ā¢ The degree of obstruction
ā¢ The cause: volvulus, hernia, luminal and mural
causes
ā¢ The degree of ischemia
ā¢ Free fluid and gas
32. Barium & Gastrografin studies
ā¢ Barium should not be used in a patient with
suspected peritonitis.
ā¢ As: follow through, enema: Limited use in the
acute setting
ā¢ Gastrografin is used in acute abdomen but is
diluted
ā¢ Useful in recurrent and chronic obstruction
ā¢ May able to define the level and mural causes.
ā¢ Can be used to distinguish adynamic and
mechanical obstruction
34. Indications for Surgery
Immediate intervention:
ā¢ Evidence of strangulation (herniaā¦.etc)
ā¢ Signs of peritonitis resulting from perforation or ischemia
In the next 24-48 hours:
ā¢ Clear indication of no resolution of obstruction ( Clinical,
radiological).
ā¢ Diagnosis is unclear in a virgin abdomen
Intermediate stage:
ā¢ The cause has been diagnosed and the patient is stabilized
35. Causes of Intestinal Ileus
ā¢ Postoperative and bowel resection
ā¢ Intraperitoneal infection or inflammation
ā¢ Ischemia
ā¢ Extra-abdominal: Chest infection, Myocardia infarction
ā¢ Endocrine: hypothyroidism, diabetes
ā¢ Spinal and pelvic fractures
ā¢ Retro-peritoneal haematoma
ā¢ Metabolic abnormalities:
ā¢ Hypokalaemia
ā¢ Hyponatremia
ā¢ Uraemia
ā¢ Hypomagnesemia
ā¢ Bed ridden
ā¢ Drug induced: morphine, tricyclic antidepressants
36. Is this an ileus or obstruction
Clinical features:
ā¢ Is there an under lying cause?
ā¢ Is the abdomen distended but tenderness is not marked.
ā¢ Is the bowel sounds diffusely hypoactive.
Radiological features:
ā¢ Is the bowel diffusely distended
ā¢ Is there gas in the rectum
ā¢ Are further investigations (CT or Gastrografin studies)
helpful in showing an obstruction.
ā¢ Does the patient improve on conservative measures
38. Initial Management in the ER
ā¢ Resuscitate:
ā¢ Air way (O2 60-100%)
ā¢ Insert 2 lines if necessary
ā¢ IVF : Crytloids at least 120 ml/h. (determined by estimated fluid loss
and cardiac function). Add K+ at 1mmmol/kg
ā¢ Draw blood for lab investigations
ā¢ NPO.
ā¢ Decompress with Naso-gastric tube and secure in position
ā¢ Insert a urinary catheter (hourly urinary measurements) and start a
fluid input / output chart
ā¢ Intravenous antibiotics (no clear evidence)
ā¢ If concerns exist about fluid overloading a central line should be
inserted
ā¢ Follow-up lab results and correction of electrolyte imbalance