Intestinal Obstruction Flashcards
Differences between Acute Obstruction vs Peritonitic
Acute obstruction:
•colic abdominal pain
•Soft, non- tender on palpation
Peritonitic
•Constant abdominal pain
•Tense and tender on palpation
What are the Zones of Head
The zones of the abdomen and the three embryological gut segments: foregut, midgut, and hindgut.
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Foregut Zones:
- Epigastric Zone: This zone includes the lower oesophagus, stomach, duodenum, and pancreas, which are derived from the foregut.
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Midgut Zones:
- Right Upper Quadrant (RUQ): The right part of the stomach and the majority of the small intestine (jejunum and ileum) are derived from the midgut.
- Right Lower Quadrant (RLQ): The cecum, appendix, and the ascending colon are also part of the midgut.
-
Hindgut Zones:
- Left Lower Quadrant (LLQ): The sigmoid colon and the majority of the descending colon are derived from the hindgut.
- Hypogastric Zone: The rectum and the distal part of the large intestine are part of the hindgut.
Conclusion:
In intestinal obstruction, Periumbilical pain suggests midgut origin, and suprapubic suggests hindgut origin
What is intestinal obstruction?
A condition in which there is impediment of cephalic- caudal propulsion of the intestinal contents by mechanical or non-mechanical
-One of the common causes of acute abdomen in our settings
Classification of IO, depending on aetiopathology
- Dynamic: peristalsis is working against a mechanical obstruction
• Associated with colicky abdominal pain
■INTRALUMINAL:
•Fecal impaction
•Foreign bodies
•Parasites: Round worms 🪱 turn into a ball after administration of antiparasitic medication
•Bezoars
•Gallstones
■MURAL: Strictures
♡Benign:
-Post anastomotic
-Schistosomiasis
-TB infection
-IBD: UC/Crohn’s disease
-Post radiation
Others
-Sigmoid valvulus
-Diverticulitis
-Intusssusception
-Polyps
◇Malignant
-Adenocarcinoma
-Sarcoma
-Neuroendocrine
■EXTRAMURAL
-Adhesions
-Hernias
-Infectious: tuberculosis
Malignancy:
-1⁰ Peritoneal Malignancy
-2⁰ Metastasis to the peritoneum
- Adynamic
-Mechanical element is absent
-Peristalsis may be absent (Paralytic ileus) or it might be present but in a non-propulsive form (Pseudo-obstruction)
-In general, its not associated with pain
Causes:
●Peritonitis
●Electrolyte imbalance
●Postoperative
●Ischaemia
●Drugs
●Retroperitoneal causes
Pathophysiology of intestinal obstruction
- Accumulation of intestinal contents
- Increased frequency and amplitude of peristalsis ( at this moment, bowel sounds have high pitch and frequency)
- Progressive Accumulation of air and fluids.
Amound of fluids produced per day
♤Saliva: 1-1.5 litres
♤Gastric juice: 2 - 3 litres
♤Pancreatic juice: 500- 1000 ml
♤Bile: 500-800 ml - Third spacing of the fluid: It’s not participating in the physiological processes of the body
- Progressive bowel distension and oedema
- Obstruction, in the order: lymphatic, venous, and then arterial
- Arterial obstruction leads to bowel necrosis and perforation
- Weakening of gap junctions: bacterial translocation
●Proximal: 10⁴
●Midgut:10⁶
●Cololon 10^14
Pathophysiology of intestinal obstruction
- Accumulation of intestinal contents
- Increased frequency and amplitude of peristalsis ( at this moment, bowel sounds have high pitch and frequency)
- Progressive Accumulation of air and fluids.
Amound of fluids produced per day
♤Saliva: 1-1.5 litres
♤Gastric juice: 2 - 3 litres
♤Pancreatic juice: 500- 1000 ml
♤Bile: 500-800 ml - Third spacing of the fluid: It’s not participating in the physiological processes of the body
- Progressive bowel distension and oedema
- Obstruction, in the order: lymphatic, venous, and then arterial
- Arterial obstruction leads to bowel necrosis and perforation
- Weakening of gap junctions: bacterial translocation
●Proximal: 10⁴
●Midgut:10⁶
●Cololon 10^14
What are the cardinal signs of intestinal obstruction
- Pain
- Tells that there is mechanical obstruction
- where pain begins tells the level
Site: The location of the pain
Onset: When the pain started
Character: The quality or type of pain (e.g. sharp, dull, burning)
Radiation: Whether the pain radiates to other areas
Associated symptoms: Any other symptoms accompanying the pain
Time course: How the pain has changed over time
Exacerbating/Relieving factors:
Severity: The severity of the pain on a scale of 1 to 10
- Abdominal distension
- Mainly in LBO - Vomiting
- In SBO, it is early and frequent - Constipation
- Occurs early in LBO
-Obstipation: absolute, no flatus
Small bowel obstruction (SBO)
High SBO: Duodenum & Jejunum
●Early profuse vomiting and dehydration
■Causes:
-Adhesions
-Lipomas
-Leiomyomas
-Congenital
Low SBO: Ileum
● Vomiting delayed
●Pain and mild central distension
Causes
-Hernias
-Adhesions
Large bowel obstruction (LBO)
●Early pronounced distension + Constipation
●Mild pain
●Vomiting and dehydration occur later
◇Location:
-Anywhere in the large intestiine
-Caecum: high risk of perforation, thanks to LaPlace’s Law
3-6-9 rule
-caecum has the largest radius
Causes:
●Colorectal carcinoma
●Volvulus
●Tuberculosis Strictures
●Diverticulitis
●Congenital megacolon
Simple vs. Strangulated obstruction?
Simple:
- Blockage without vascular compromise
Strangulated: surgical emergency
-Vascular compromise
-Associated with: hernia, volvulus, closed loop obstruction, intussusception, mesenteric infarction, adhesions
Clinical features of strangulation
●Pyrexia >38⁰C
●Tachycardia
●Tachypnea
●Constant abdominal pain
●Rebound tenderness
●Shock
Clinical Examination of IO
●Introduction and explanation of the procedure
●General examination:
ABDOMEN
Inspection:
- end of the bed, closer to the bed
Symmetry
Distension
Umbilicus
Visible peristalsis
Visible mass
Distended veins
