Gut Motility Disorders: Failure of Transit through Bowel
First Things First (assess & treat for the following)
The first step in dealing w/ gut dysmotility is to differentiate ileus from obstruction. Whereas ileus typically resolves w/ supportive care only, & without sequelae, obstruction rarely resolves w/out surgical intervention & can have serious consequences if not aggressively managed.
- Ileus is functional failure (no demonstrable obstruction) of the gut to propel contents & can be classified as:
- Adynamic ileus is an inhibition of the neuromuscular complex, also referred to as pseudo-obstruction.
- Primary adynamic ileus is idiopathic (ie, Ogilvie’s syndrome).
- Most adynamic ileus is secondary to well-known causes:
- Postop ileus related to CNS & neural reflexes, hormones, medication & anesthetic agents is normal when it involves the small bowel for up to 24 hrs, the stomach up to 48 hrs & the colon for up to 72 hrs.
- When postop ileus is prolonged or recurrent, considerations should include:
- Intra-abdominal inflammation
- Systemic sepsis
- Intra-abdominal or retroperitoneal hematoma
- Occult wound infection
- Commonly seen after trauma, including:
- Spinal cord injury
- Spine fracture
- Rib fractures
- Pelvic fracture
- Common w/ pulmonary atelectasis or pneumonia in the basal segments
- Drugs that inhibit gut motility include:
- Narcotics
- Anticholinergic agents
- Antihistamines
- Psychotropic drugs such as haloperidol or tricyclic antidepressants
- Phenothiazines
- Ganglionic blocking agents
- Metabolic causes of ileus are common:
- Hypokalemia
- Hyponatremia
- Hypomagnesemia
- Other metabolic causes include:
- Uremia
- Diabetes
- Hypoparathyroidism
- Miscellaneous causes
- Scleroderma
- Amyloidosis
- Spastic ileus is related to hypermotility where uncoordinated peristalsis fails to push contents through.
- Ischemic ileus is related to vascular occlusion & infarction of the myoelectric components.
- Adynamic ileus is an inhibition of the neuromuscular complex, also referred to as pseudo-obstruction.
- Obstruction is the physical barrier to movement of bowel contents. In general, the 3 categories include:
- Extraluminal causes
- Adhesions
- Hernias
- Carcinomas
- Abscesses
- Lesions intrinsic to the bowel wall
- Primary tumors
- Inflammatory bowel disease (Crohn’s disease)
- Intraluminal causes
- Gallstones
- Enteroliths
- Foreign bodies
- Bezoars
- 80% of bowel obstruction involves the small bowel; the most common etiologies are:
- Postop adhesions (65-80%); pelvic procedures, specifically gynecologic, appendectomy & colorectal resection, account for 60% of obstructions due to adhesions
- Hernia (15-25%)
- Ventral hernia is the most common.
- Inguinal & internal hernias are common.
- Less common are femoral, obturator, lumbar & sciatic.
- Tumors (10-15%)
- The majority are metastatic lesions that implant through hematogenous spread to the peritoneum.
- Large intra-abdominal tumors can cause obstruction from extraluminal compression.
- Obstructing primary small bowel tumors are rare.
- Crohn’s disease (5%) is the 4th leading cause of small bowel obstruction.
- Inflammation & edema that resolves w/ nonoperative mgt
- Stricture that may require resection & reanastomosis or stricturoplasty
- Abscess can cause obstruction by involving a portion of the intestinal wall, by adhesion or as a result of localized ileus & functional obstruction. Common etiologies include:
- Ruptured appendix
- Diverticulitis
- Dehiscence of abdominal anastomosis
- Miscellaneous other etiologies include:
- Intussusception, more common in children; in adults is usually associated w/ a lead point such as a polyp, tumor or Meckel’s diverticulum
- Enteroliths from jejunal diverticula
- Foreign bodies
- Phytobezoars
- 20% of obstructions involve the colon; the most common etiologies include:
- Cancer (60%)
- Diverticulitis (15%)
- Volvulus (15%)
- Extraluminal causes
If obstruction is present, the second step is to determine whether & how urgently surgical intervention is needed.
- Only about 20% of partial obstructions will require surgical intervention, which can usually be done on a semi-elective (planned) basis.
- Complete obstruction almost always requires surgical intervention, usually on an emergency basis.
- The vast majority of obstructions are classified as simple, implying an intact blood supply (ie, gallstone ileus).
- Strangulated obstruction implies mesenteric vessel occlusion & is associated w/ a higher morbidity & mortality; therefore, early recognition is important.
- Closed loop obstruction involves occlusion of both afferent & efferent limbs of bowel & is especially dangerous because of rapid progression to strangulation & perforation even before clinical evidence of obstruction. The following closed loop obstructions require emergent surgical intervention if bowel resection is to be avoided:
- Volvulus
- Incarcerated ventral hernia
- Congenital bands
- Adhesions
- Malrotation
- Internal hernia
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Last updated: May 2, 2010
Citation
"Gut Motility Disorders: Failure of Transit Through Bowel." Pocket ICU Management, PocketMedicine.com, Inc, 2010. Anesthesia Central, anesth.unboundmedicine.com/anesthesia/view/Pocket-ICU-Management/534089/all/Gut_Motility_Disorders:_Failure_of_Transit_through_Bowel.
Gut Motility Disorders: Failure of Transit through Bowel. Pocket ICU Management. PocketMedicine.com, Inc; 2010. https://anesth.unboundmedicine.com/anesthesia/view/Pocket-ICU-Management/534089/all/Gut_Motility_Disorders:_Failure_of_Transit_through_Bowel. Accessed October 10, 2024.
Gut Motility Disorders: Failure of Transit through Bowel. (2010). In Pocket ICU Management. PocketMedicine.com, Inc. https://anesth.unboundmedicine.com/anesthesia/view/Pocket-ICU-Management/534089/all/Gut_Motility_Disorders:_Failure_of_Transit_through_Bowel
Gut Motility Disorders: Failure of Transit Through Bowel [Internet]. In: Pocket ICU Management. PocketMedicine.com, Inc; 2010. [cited 2024 October 10]. Available from: https://anesth.unboundmedicine.com/anesthesia/view/Pocket-ICU-Management/534089/all/Gut_Motility_Disorders:_Failure_of_Transit_through_Bowel.
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