9. Ileus (diagnosis and treatment)

Question 1

Mechanical ileus

Answer 1

Obstruction may cause mesenteric compromised by mesenteric strangulation, resulting in ischaemia and bowel necrosis. Thus, in mechanical ileus, surgery is indicated

Question 2

Functional ileus

Answer 2

Due to disruption of peristalsis

Question 3

Mechanical causes (most common)

Answer 3

Small bowel
• Postop adhesions
• Hernia

Large bowel 
• Volvulus
• IBD
• Ingestion of foreign body
• Intussusception
• Closed loop obstruction

Question 4

Postoperative adhesions

Answer 4

Fibrous scar tissue pinches bowels after surgery

Question 5

Hernia

Answer 5

Can cause pinching of bowels at point of penetration, blocking it

Question 6

Volvulus

Answer 6

Twisting of instestine loops, can occur around masses (colorectral cancer)

Question 7

Intussusception

Answer 7

The bowel folds back into itself

Question 8

Closed loop obstruction

Answer 8

Both ends of a segment is obstructed, where nothing comes in, and nothing comes out.

Question 9

Reason for cramping abdominal pain

Answer 9

Accumulation of gas and stool proximal to obstruction -> dialation of the bowel -> pain

Could also be caused by ischemia or foreign object depending on the situation

Question 10

Reasons for electrolyte abnormalities and dehydration

Answer 10

• Nausea and vomiting

* Edema from dialated colon

Question 11

Reason for respiratory distress during ileus

Answer 11

Dialation of bowel -> upward pressure on diaphragm

Question 12

Small bowel: pain and vomiting compared to large bowel ileus

Answer 12

Vomiting
• More common
Pain
• periumbilical, cramping and intermittent pain
• lasts for a few minutes

Question 13

Large bowel: pain and vomiting compared to small bowel ileus

Answer 13

Vomiting
• less common 
Pain
• localized lower in abdomen
• bouts are less frequent, but lasts longer

Question 14

Complications: Excessive bowel dialation

Answer 14

Increase in pressure unitl blood vessels in bowel walls collapse -> ischemia -> necrosis and perforation

Question 15

Symptoms of microperforation

Answer 15

Focal, CONSTANT pain due to irritation

Question 16

Symptoms of large bowel perforation

Answer 16

Sudden relief of pain due to pressure decrease, followed by progressive worsening as generalized peritonitis sets in

Question 17

Diagnosis: regular lab studies

Answer 17

Complete blood count with differential
• leukocyte increase with neutrophil predom = underlying inflammatory response (IBD, diverticulitis)
• Anemia due to IBD or colorectal cancer

Metabolic markers
• Elektrolytes, BUN, creatinine

If clinical signs of peritonitis or sepsis
• blood cultures

Question 18

Diagnosis: lab studies for patients with severe symptoms (fever, tachycardia, hypotension and altered mental status)

Answer 18

Severe symptoms -> arterial blood gas and serum lactate

• metabolic acidosis and increased lactate suggests bowel ischemia

Question 19

Diagnosis: imaging

Answer 19

• Abdominal X-ray
• CT if patient does not require immediate surgery
• US (patients who can’t undergo CT)

Question 20

Diagnosis: X-ray findings

Answer 20

• Dialated loops
• Air-fluid levels
• Usually shows proximal bowels being dialated, but not distal

Specific signs
• Apple core sign - ring shaped colon cancer

Question 21

Diagnosis: general CT findings

Answer 21

CT is usually done to assist in specific diagnosis if patient does not require emergency surgery

• Bowel wall thickening
• Submucosal edema
• Mesenteric edema and hemorrhage

Question 22

Diagnosis: specific CT findings

Answer 22

• Target sign - shows intussusception

* Whirl sign - due to rotation of mesentery; suggests volvulus

Question 23

Diagnosis: US findings

Answer 23

• Distented bowel loop > 2.5cm
• To & Fro sign (bowel contents moves back and forth)
• Keyboard sign (thickening of plicae circulares in inner mucosal lining)

Question 24

Conservative management of ileus: Supportive care

Answer 24

• IV fluids
• Correction of electrolyte imbalance
• Gastrointestional decompression

Question 25

Gastrointestional decompression

Answer 25

Nasogastric tube inserted in order to empty bowels

Used for patients with persistent nausea, vomiting and distention

Question 26

Management of partial obstruction

Answer 26

Should self-resolve within 5 days. If not -> surgical exploration

• Supportive care
• Gastrografin
• Repeat abdominal x-rays

Question 27

Gastrografin

Answer 27

oral hypertonic contrast agent that can pull water back into the lumen, decreasing edema -> stimulation of peristalsis

Question 28

Management of cancers

Answer 28

• small / low staged ones may be resected
• if spread to lymph node -> chemotherapy
• metastatic cancers rarely gets curative resection, but rather palliative treatment for symptoms instead

Question 29

Use of stenting in ileus

Answer 29

• placed endoscopically

• preoperative decompression for patients with acute mechanical obstruction
• palliation for metastatic cancer patients

Question 30

Stoma

Answer 30

• may be temporary as a bridge between two surgeries

* may also be permanent, if the resection is too large, and you can’t anastemose the bowels back together