Ileus resident survival guide
|Ileus Resident Survival Guide Microchapters|
Synonyms and Keywords: Approach to functional ileus, Approach to mechanical obstruction, Ileus workup, Ileus diagnostic approach
Ileus is defined as reduction in intestinal motility, which is either due to an obstruction (mechanical ileus) or due to intestinal paralysis (functional ileus). Reduction or cessation of intestinal peristalsis prevent effective transmission of intestinal content leading to constipation and abdominal distension. Nevertheless, onset and severity of symptoms depend on extent and location of obstruction in mechanical ileus. Although proximal obstructions are presented acutely with nausea, vomiting, abdominal pain and obstipation, distal involvements usually take longer to become symptomatic. It is critical to differentiate two types of ileus and determining the etiology when encountering a suspected patient, since different approaches are available for each. Surgical intervention is usually recommended for treatment of mechanical obstructions, specifically complete obstructions, whereas conservative management which has been effective in management of functional ileus and some of partial mechanical obstruction cases.
Life Threatening Causes
Common Causes of Functional Ileus
- Reflectory ileus due to abdominal, pelvic or retroperitoneal surgeries
- Medications such as narcotics, anticholinergics, calcium channel blockers and antipsychotics
- General anaesthesia
- Electrolyte disturbance, such as hypokalemia, hyponatremia and hypocalcemia
- Diabetes Mellitus
- Intestinal hypoperfusion
- Ogilvie syndrome
- Guillain-Barré syndrome
Common Causes of Mechanical Ileus
- Infections or inflammations that affect the bowel wall such as diverticulitis.
- Fecal impaction
- Adhesion (eg, due to a previous surgery)
- Volvulus (eg, sigmoid volvulus)
- Gallstone ileus
- Shown below is a table summarizing the clinical presentations of both small bowel obstruction and ileus types of ileus.
|Suggest Mechanical Ileus||Suggest Functional Ileus|
|Obstination (patient cannot pass stool or gas)¶||Patient cannot pass gas and minimal or absent stool passage|
|Nausea and vomiting (especially billious vomiting)||Nausea and vomiting†|
|Abdominal distension||Minimal to moderate abdominal distension|
|Increased bowel sounds‡||Decreased or absent bowel sounds|
|Severe abdominal tenderness and guarding|
¶Not if a partial mechanical obstruction.
Abbreviations: CBC: complete blood count; WBC: white blood cell; CRP: C reactive protein; BUN: blood urea nitrogen, ABG: arterial blood gas; IV: intravenous
1) History taking:
3) Laboratory investigations:
|Supine and erect plain abdominal x-ray|
|Distended large bowel (especially cecum)||Distended small bowel loops||Subdiaphragmatic air||Inconclusive findings|
|Findings favor mechanical ileus||Findings favor functional ileus|
Abbreviations: WBC: White blood cell; CRP: C reactive protein; IV: Intravenous; NGT: Nasogastric tube
|Presence of these findings||Surgical intervention, such as exploratory laparotomy|
•Severe abdominal pain and vomiting
•Physical findings of peritonitis, such as guarding
•Severely disturbed laboratory results (WBC>10.500 or CRP>75
•Radiologic findings of perforation, such as free intraperitoneal or subdiaphragmatic air
•Radiologic findings of strangulation, such as increased bowel wall density, localized mesenteric fluid accumulation (specifically>500ml) and mesenteric congestion
•Evidences of complete obstruction
|Absence of these findings||Non operative managements|
•Fluid resuscitation (IV)
•In the presence of vomiting, Consider decompression with NGT
•Correct any electrolyte disturbances
•Antibiotic therapy if there is any clinical or laboratory finding of infection
•Consider neostigmine if Ogilvie syndrome
•Consider barium enema and/or digital fecal disimpaction if fecal impaction
- Administration of water soluble contrast for CT scan is preferred. Moreover, in conservative management administration of 100 mg of water-soluble, iodinated contrast medium per nasogastric tube is recommended for better evaluation. This could be helpful, specially when considering the conservative management. If contrast medium is seen in colon after 24 hours, conservative management should be continued. 
- Don't use CT scan with barium contrast due to it's irritative nature, specifically in presence of perforation.
- Don't use vagolytic agents such as butylscopolamine for pain control, due to their antiperistaltic effect.
- Avoid routine nasal tube insertion in all patients suspected to ileus, since this intervention may only longer the ileus duration.
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