9. Ileus (diagnosis and treatment) Flashcards
Mechanical ileus
Obstruction may cause mesenteric compromised by mesenteric strangulation, resulting in ischaemia and bowel necrosis. Thus, in mechanical ileus, surgery is indicated
Functional ileus
Due to disruption of peristalsis
Mechanical causes (most common)
Small bowel
• Postop adhesions
• Hernia
Large bowel • Volvulus • IBD • Ingestion of foreign body • Intussusception • Closed loop obstruction
Postoperative adhesions
Fibrous scar tissue pinches bowels after surgery
Hernia
Can cause pinching of bowels at point of penetration, blocking it
Volvulus
Twisting of instestine loops, can occur around masses (colorectral cancer)
Intussusception
The bowel folds back into itself
Closed loop obstruction
Both ends of a segment is obstructed, where nothing comes in, and nothing comes out.
Reason for cramping abdominal pain
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
Reasons for electrolyte abnormalities and dehydration
- Nausea and vomiting
* Edema from dialated colon
Reason for respiratory distress during ileus
Dialation of bowel -> upward pressure on diaphragm
Small bowel: pain and vomiting compared to large bowel ileus
Vomiting • More common Pain • periumbilical, cramping and intermittent pain • lasts for a few minutes
Large bowel: pain and vomiting compared to small bowel ileus
Vomiting • less common Pain • localized lower in abdomen • bouts are less frequent, but lasts longer
Complications: Excessive bowel dialation
Increase in pressure unitl blood vessels in bowel walls collapse -> ischemia -> necrosis and perforation
Symptoms of microperforation
Focal, CONSTANT pain due to irritation
Symptoms of large bowel perforation
Sudden relief of pain due to pressure decrease, followed by progressive worsening as generalized peritonitis sets in
Diagnosis: regular lab studies
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
Diagnosis: lab studies for patients with severe symptoms (fever, tachycardia, hypotension and altered mental status)
Severe symptoms -> arterial blood gas and serum lactate
• metabolic acidosis and increased lactate suggests bowel ischemia
Diagnosis: imaging
- Abdominal X-ray
- CT if patient does not require immediate surgery
- US (patients who can’t undergo CT)
Diagnosis: X-ray findings
- Dialated loops
- Air-fluid levels
- Usually shows proximal bowels being dialated, but not distal
Specific signs
• Apple core sign - ring shaped colon cancer
Diagnosis: general CT findings
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
Diagnosis: specific CT findings
- Target sign - shows intussusception
* Whirl sign - due to rotation of mesentery; suggests volvulus
Diagnosis: US findings
- Distented bowel loop > 2.5cm
- To & Fro sign (bowel contents moves back and forth)
- Keyboard sign (thickening of plicae circulares in inner mucosal lining)
Conservative management of ileus: Supportive care
- IV fluids
- Correction of electrolyte imbalance
- Gastrointestional decompression
Gastrointestional decompression
Nasogastric tube inserted in order to empty bowels
Used for patients with persistent nausea, vomiting and distention
Management of partial obstruction
Should self-resolve within 5 days. If not -> surgical exploration
- Supportive care
- Gastrografin
- Repeat abdominal x-rays
Gastrografin
oral hypertonic contrast agent that can pull water back into the lumen, decreasing edema -> stimulation of peristalsis
Management of cancers
- 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
Use of stenting in ileus
• placed endoscopically
- preoperative decompression for patients with acute mechanical obstruction
- palliation for metastatic cancer patients
Stoma
- 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
