Intestinal Obstruction
Intestinal Obstruction: Excerpt from The 5-Minute Pediatric Consult
Vered Yehezkely-Schildkraut, MD
Raanan Shamir, MD
Intestinal Obstruction - BASICS
Intestinal Obstruction - description
- Pathologic blockage of progression of intestinal contents:
- May be partial or complete
- May arise from intrinsic abnormalities (e.g., meconium ileus or intestinal atresia) or extrinsic abnormalities (e.g., adhesions and volvulus).
- Paralytic ileus: Failure of intestinal motor function without mechanical obstruction:
- Very common after abdominal operations.
- Common causes:
- Infection (pneumonia, gastroenteritis, peritonitis, systemic sepsis)
- Drugs (i.e., opiates, loperamide, vincristine)
- Metabolic abnormalities (hypokalemia, uremia, myxedema, and diabetic ketoacidosis)
- Chronic intestinal pseudo-obstruction: A severe intestinal motility disorder described in diverse diseases including muscular, endocrine, metabolic and autoimmune disorders. Examples include Duchenne and diabetes mellitus.
Intestinal Obstruction - epidemiology
The different causes have their own identified epidemiologic patterns:
- Postoperatve adhesions occur very often after all laparotomies
- Small bowel obstruction secondary to Ascaris lumbricoides in tropical and subtropical countries
- Colonic volvulus secondary to aerophagia and constipation in mentally retarded children
- Meconium ileus equivalent in children with cystic fibrosis
Intestinal Obstruction - incidence
Occurs in ~1 in 1,500 live births
Intestinal Obstruction - prevalence
Down syndrome (with a high prevalence, 20–30%, of duodenal atresia)
Intestinal Obstruction - pathophysiology
- Mechanical obstruction:
- Intestinal contents accumulate proximal to the site of obstruction.
- The bowel distends with swallowed air, ingested food, secretions, and gases from intestinal reactions and bacterial fermentation.
- Retrograde flow of intestinal contents and reflex gut distention cause vomiting.
- Internal and external losses result in hypovolemia, oliguria, and azotemia.
- Bacteria proliferate in the small bowel and its contents become feculent.
- Strangulation obstruction (impaired blood flow to the intestine in addition to intestinal content obstruction):
- Loss of plasma into the bowel, leading more rapidly to shock
- When strangulation progresses, gangrene, peritonitis, and perforation may ensue.
- Damage to the normal gut barrier may enable bacteria, bacterial toxins, and inflammatory mediators to enter the circulation causing sepsis
Intestinal Obstruction - etiology
- Neonates:
- Atresia of the intestine (33% of all neonatal obstructions, 1:2700 newborns)
- Meconium ileus (30% of all neonatal obstructions, almost all caused by cystic fibrosis) and meconium plug
- Anorectal malformation: Anal atresia and stenosis (1 in 4,000–8,000 newborns)
- Necrotizing enterocolitis
- Hirschsprung disease
- Infants:
- The most common cause of intestinal obstruction is pyloric stenosis.
- The 2nd most common is intussusception (the most common cause between 3 months and 6 years of age, with 60% of cases occurring before 1 year of age).
- Other, less common causes:
- Postoperative intestinal obstruction and adhesion
- Incarcerated or strangulated inguinal hernia. Inguinal hernias have 10–28% risk for incarceration
- Hirschsprung disease
- Duplications
- Meckel diverticulum
- Older children:
- Malrotation
- Annular pancreas
- Meckel diverticulum
- Cancer-related intestinal obstruction, and radiotherapy induced adhesions
- Superior mesenteric artery syndrome
- Corrosive injury-induced gastric outlet obstruction
- Esophageal injury or foreign body ingestion (e.g., coin in esophagus)
- Postoperative intestinal obstruction and adhesions
- Juvenile polyposis and related syndromes (e.g., Peutz-Jeghers)
- Inflammatory bowel disease
- Meconium ileus equivalent (occurs only in patients with cystic fibrosis)
- Roundworm (A. lumbricoides)
- Gastric and intestinal bezoars
Intestinal Obstruction - DIAGNOSIS
There is no spontaneous resolution of inguinal hernia. Surgery should be scheduled before incarceration occurs.
Intestinal Obstruction - signs & symptoms
- Presentation may be acute and obvious or chronic and subtle. The latter and partial obstruction could be difficult to diagnose.
- Careful history, physical examination, and consideration of age related etiology most often will identify the specific cause.
Intestinal Obstruction - history
- The classic symptoms of intestinal obstruction include vomiting (often bile stained), abdominal distention, colicky abdominal pain, and failure to pass stool.
- In neonates:
- History of maternal polyhydramnios and aspiration of >20 mL gastric fluid after birth are suggestive of high intestinal obstruction.
- Most healthy full-term children should pass meconium within 48 hours of birth. If no meconium at 48 hours, suspect obstruction
- Older children:
- Pain is one of the cardinal manifestations can be poorly localizedcolicky visceral pain or sharp peritoneal pain.
- Nausea and vomiting: High obstruction causes bilious emesis; distal obstruction may lead feculent emesis; in colonic obstruction vomiting may be absent or late.
- No passage of stool in low obstruction or bloody stool with mucus in strangulation (associated with intussusception and volvulus).
Neonates, more so than older children, with unrecognized intestinal obstruction deteriorate rapidly, with increased morbidity, mortality, and surgical complications.
Intestinal Obstruction - physical exam
- General assessment and vital signs, as the patient could be dehydrated, septic, or malnourished
- Palpation may reveal the presence of a hernia, a mass suggestive of feces, or intussusception. Tenderness and rigidity result from peritonitis.
- Bowel sounds may be initially increased, but later on are decreased, occasional or absent.
- Anal inspection excludes anal atresia and stenosis. Rectal examination reveals, at times, a palpable polyp or intussusceptum and blood (overt, occult, the “currant jelly” typical of intussusception).
- Strangulation is suspected when there is fever, tachycardia, signs of peritonitis, and severe pain that persists after nasogastric decompression.
Intestinal Obstruction - tests
Intestinal Obstruction - lab
- No laboratory studies are diagnostic.
- Electrolyte abnormalities, including sodium, chloride, bicarbonate, and potassium, are necessary to identify for the proper assessment of hydration and 3rd spacing of fluids.
- High obstruction may lead to hypochloremic, hyperkalemic metabolic alkalosis.
- Bowel infarction may lead to marked leukocytosis, thrombocytopenia, and metabolic acidosis.
- Serum amylase and lipase should be determined to rule out pancreatitis, but they might be mildly elevated in intestinal obstruction.
Intestinal Obstruction - imaging
- Plain abdominal x-rays in the supine and erect or decubitus views will identify the classic features of a gasless abdomen, with air-fluid levels and distended loops of intestine. However, high small bowel obstruction or strangulation obstruction may present with normal or nearly normal x-rays.
- In small bowel obstruction: Dilated bowel, air-fluid levels without gas in the colon, and multiple dilated loops in distal obstruction
- Paralytic ileus may present with dilation of the small and large intestines.
- Duodenal obstruction with “double-bubble” gas shadow
- “Target sign” in intussusception
- Pneumoperitoneum in perforation
- Peritoneal calcifications in meconium peritonitis
- Obstruction with intraluminal calcifications in rectourinary fistula, colonic aganglionosis, or intestinal atresia
- Right lower quadrant ground-glass appearance in meconium ileus
- Ultrasonography: To identify a mass (i.e., perforated appendix), pyloric stenosis, malrotation, volvulus, or intussusception (in which it can replace the contrast examination in combination with “air” enema)
- CT: Small and large bowel obstruction, diagnosis of strangulation; helpful in postoperative obstruction, Crohn disease, and neoplasms. High cost and radiation exposure make it a subject of debate in general and in younger patients in particular
- Contrast examinations:
- Barium enema to confirm intussusception or Hirschsprung disease
- Upper GI series to exclude malrotation or volvulus
- Water-soluble, low osmolarity materials should be preferred (risk of perforation).
- Evaluation for other associated congenital anomalies (the most frequent are cardiac and renal abnormalities) is mandatory, as some are life threatening. Associated malformations are frequently associated with duodenal atresia and to a lesser extent with jejunoileal atresia.
Intestinal Obstruction - differencial diagnosis
Other causes of abdominal pain and vomiting should be considered:
- Appendicitis, torsion of testis or ovary, lower lobe pneumonia: Must be ruled out by history and physical examination
- Pancreatitis
- Sickle cell crisis
- Henoch-Schönlein purpura
- Biliary colic
- Lead poisoning
- Acute adrenal insufficiency
- Diabetic ketoacidosis
- Acute intermittent porphyria
Intestinal Obstruction - TREATMENT
Intestinal Obstruction - initial stabilization
- Hold oral intake.
- Decompress the stomach by nasogastric tube.
- Administer IV hydration, correct electrolyte imbalance, and ensure adequate urine output.
- Identify etiology of obstruction and establish definitive repair.
- Cultures and broad-spectrum antibiotics (such as cefoxitin or gentamicin and clindamycin or metronidazole in combination) according to patient’s age and status
Intestinal Obstruction - general measures
- In intussusception, hydrostatic or air reduction is successful in 90% of cases.
- Nasogastric decompression or anti-inflammatory medication for adhesions or inflammatory strictures
- Contrast-material enemas, manipulation, and direct enteral irrigation with N-acetylcysteine for uncomplicated meconium ileus
- Manual reduction of incarcerated inguinal hernia
- Colonic volvulus may be treated with endoscopic decompression followed by elective bowel resection.
- Endoscopic removal of foreign bodies
- Paralytic ileus is usually self-limiting and resolves with conservative therapy and medication such as prokinetic agents (metoclopramide and erythromycin).
Intestinal Obstruction - special therapy
- Conservative management with decompression by nasogastric tube and IV fluids should be initiated 1st rather than operating in:
- Early postoperative, partial, and recurrent adhesive obstructions
- Necrotizing enterocolitis
- Intussusception
- Meconium ileus
- Duodenal hematomas
- Superior mesenteric artery syndrome
- Crohn disease
- Successful treatment of adhesive small bowel obstruction with gastrografin and oral medications (laxatives) has been reported in adults.
Intestinal Obstruction - surgery
- Definitive treatment requires an urgent operation.
- Exceptions to this rule include are the above mentioned conditions managed conservatively. However, if no improvement within 12–24 hours, surgery is advisable.
- The surgical procedure is individualized according to the specific type, site, anatomy of the obstruction, and associated conditions.
Intestinal Obstruction - medication
Intestinal Obstruction - first line
- Pain relief
- Different medications for specific disorders.
Intestinal Obstruction - FOLLOW UP
Intestinal Obstruction - prognosis
- Varies with different causes of intestinal obstruction, age of the patient, presence of prematurity, and associated anomalies
- Associated complications and the institution of prompt treatment influence outcome.
- Short bowel syndrome continues to be a major impediment to improved survival rate; permanent parenteral nutrition is associated with morbidity and mortality.
Intestinal Obstruction - complications
May result from delayed operation:
- Dehydration
- Intestinal ischemia with sepsis and shock
- Bowel perforation and peritonitis
- Short-gut syndrome after extensive necrosis and/or resection.
Intestinal Obstruction - bibliography
- Connor FL, Di Lorenzo C. Chronic intestinal pseudo-obstruction: Assessment and management. Gastroenterology. 2006;130:S29–S36.
- Dalla Vecchia LK, Grosfeld JL, West KW, et al. Intestinal atresia and stenosis: A 25-year experience with 277 cases. Arch Surg. 1998;133:490–496.
- Frager D. Intestinal obstruction role of CT. Gastroenterol Clin North Am. 2002;31:777–799.
- Hajivassiliou CA. Intestinal obstruction in neonatal/pediatric surgery. Semin Pediatr Surg. 2003;12:241–253.
- Loening-Baucke V, Kimura K. Failure to pass meconium: Diagnosing neonatal intestinal obstruction. Am Fam Physician. 1999;60:2043–2050.
- McCollough M, Sharieff GQ. Abdominal pain in children. Pediatr Clin North Am. 2006;53:107–137
Intestinal Obstruction - CODES
Intestinal Obstruction - icd9
560.9 Unspecified intestinal obstruction
Intestinal Obstruction - FAQ
- Q: Will my child need surgery for this problem?
- A: Most likely; surgical treatment is necessary to correct the cause of intestinal obstruction, except in a few cases, such as intussusception, pseudo-obstruction, and paralytic ileus.
- Q: What is the most common cause of this problem in my 3-day-old son?
- A: In an infant, the most common causes are atresias of the intestine, which are absences of the normal amount of large or small intestine in the abdomen.
Book Source Details
- Book Title: The 5-Minute Pediatric Consult
- Author(s): M. William Schwartz MD; et al.
- Year of Publication: 2008
- Copyright Details: The 5-Minute Pediatric Consult, Copyright © 2008 Lippincott Williams & Wilkins.
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Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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More About This Book:
Title: The 5-Minute Pediatric Consult
Authors: M. William Schwartz MD; et al.
Publisher: Lippincott Williams & Wilkins
Copyright: 2008
ISBN: 0-7817-7577-9
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