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Intestinal Obstruction

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Intestinal Obstruction

para>If patient is an elderly, consider:

Predominant sex: male = female

In the United States: Intestinal obstruction accounts for ~20% of all admissions for acute abdominal conditions.

Treat underlying conditions (e.g., tumors and hernias) to reduce the risk of obstruction.

Initial Tests (lab, imaging)

Antibiotic use is controversial in the absence of sepsis. In general, prophylactic broad-spectrum antibiotics (gram-negative, gram-positive, and anaerobic coverage) are administered around the time of surgery.

Normal saline or lactated Ringer solution with potassium supplementation, as necessary

Careful attention to input/output and volume status

NPO until obstruction resolved, then progressive return to normal

11 Schraufnagel D, Rajaee S, Millham FH. How many sunsets? Timing of surgery in adhesive small bowel obstruction: a study of the Nationwide Inpatient Sample. J Trauma Acute Care Surg. 2013;74(1):187-189.22 Kelly KN, Iannuzzi JC, Rickles AS, et al. Laparotomy for small-bowel obstruction: first choice or last resort for adhesiolysis? A laparoscopic approach for small-bowel obstruction reduces 30-day complications. Surg Endosc. 2014;28(1);65-73.33 Pirlet IA, Slim K, Kwiatkowski F, et al. Emergency preoperative stenting versus surgery for acute left-sided malignant colonic obstruction: a multicenter randomized controlled trial. Surg Endosc. 2011;25(6):1814-1821.

  • Colonic neoplasm
  • Chronic constipation/fecal impaction
  • Pseudoobstruction (Ogilvie syndrome)
  • Volvulus

In young children and infants, consider:

  • Pyloric stenosis: infant 3 to 6 weeks of age with postprandial, nonbilious, projectile vomiting
  • Intestinal malrotation/volvulus: sudden-onset, bilious vomiting with acute abdomen symptoms
  • Hirschsprung disease: failure to pass stool in first days of life, explosive expulsion of gas, and stool after digital rectal exam
  • Intussusception: distention, intermittent abdominal pain, currant jelly stools

In gastric bypass patients, consider:

  • Internal hernia: sudden onset of abdominal pain, vomiting, abdominal distention, and "whirl" sign on CT

EPIDEMIOLOGY

ETIOLOGY AND PATHOPHYSIOLOGY

  • Mechanical bowel obstruction causes distention and accumulation of fluid and gas in bowel lumen.
  • Increased intraluminal pressure and peristaltic contractions increases capillary and venous pressure of bowel wall while decreasing absorption and lymphatic drainage. This may lead to bowel ischemia and necrosis if obstruction is prolonged.
  • Luminal lesions:Stool impactionGallstonesMeconium (newborns)Intussusception
  • Intrinsic lesions:Congenital (e.g., atresia and stenosis, imperforate anus, duplications, Meckel diverticulum)Trauma: foreign bodyInflammatory (e.g., Crohn disease, diverticulitis, ulcerative colitis, radiation, toxic ingestions)Neoplastic (most common cause of large bowel obstruction in adults)Miscellaneous (e.g., endometriosis, pseudomyxoma peritonei)
  • Extrinsic lesionsAdhesions (most common cause of small bowel obstruction in adults; history of prior abdominal surgery)HerniaMasses (e.g., annular pancreas, anomalous vasculature, abscess and hematoma, neoplasm)VolvulusNeuromuscular defect (e.g., megacolon, neuro-/myopathic motility disorders)
  • Stool impaction
  • Gallstones
  • Meconium (newborns)
  • Intussusception
  • Congenital (e.g., atresia and stenosis, imperforate anus, duplications, Meckel diverticulum)
  • Trauma: foreign body
  • Inflammatory (e.g., Crohn disease, diverticulitis, ulcerative colitis, radiation, toxic ingestions)
  • Neoplastic (most common cause of large bowel obstruction in adults)
  • Miscellaneous (e.g., endometriosis, pseudomyxoma peritonei)
  • Adhesions (most common cause of small bowel obstruction in adults; history of prior abdominal surgery)
  • Hernia
  • Masses (e.g., annular pancreas, anomalous vasculature, abscess and hematoma, neoplasm)
  • Volvulus
  • Neuromuscular defect (e.g., megacolon, neuro-/myopathic motility disorders)

RISK FACTORS

  • Previous abdominal and/or pelvic surgery
  • Hernia
  • Chronic constipation
  • Cholelithiasis
  • Inflammatory bowel disease
  • Ingested foreign bodies: pica
  • Diverticular disease

GENERAL PREVENTION

DIAGNOSIS

HISTORY

  • Abdominal pain:DiffusePoorly localized cramping generally at intervals of 5 to 15 minutes
  • Abdominal distention:More common with distal obstructions
  • Emesis:Usually occurs immediately after obstructionMore frequent in proximal obstruction; unusual in colon obstruction until small bowel distension occurs
  • Obstipation:Common symptomMay pass contents distal to obstruction within first 24 hours of obstruction, especially in proximal intestinal obstructionPain followed by explosive diarrhea is often seen in partial obstruction.
  • Diffuse
  • Poorly localized cramping generally at intervals of 5 to 15 minutes
  • More common with distal obstructions
  • Usually occurs immediately after obstructionMore frequent in proximal obstruction; unusual in colon obstruction until small bowel distension occurs
  • More frequent in proximal obstruction; unusual in colon obstruction until small bowel distension occurs
  • Common symptom
  • May pass contents distal to obstruction within first 24 hours of obstruction, especially in proximal intestinal obstruction
  • Pain followed by explosive diarrhea is often seen in partial obstruction.

PHYSICAL EXAM

  • Vital signs and hemodynamic stability. General appearance
  • Inspection: distension (a late finding) less likely in proximal obstructions
  • Auscultation: high-pitched bowel sounds, peristaltic rushes
  • Palpation: Tenderness, mass, or presence of peritoneal signs may suggest strangulation or perforation.
  • Rectal examination: may reveal fecal impaction; occult blood may suggest colon malignancy.

DIFFERENTIAL DIAGNOSIS

  • Adynamic ileus
  • Colonic pseudoobstruction (Ogilvie syndrome)

DIAGNOSTIC TESTS & INTERPRETATION

  • Primarily a clinical and radiographic diagnosisAbdominal and chest radiographs to confirm diagnosis of intestinal obstruction:Distension of small bowel or colonAir-fluid levels (may be seen in ileus, gastroenteritis, constipation)Lack of colon gas (in small bowel obstruction)Free intraperitoneal air (strangulation with perforation)"Coffee bean sign" or "bent inner tube" appearance for colonic volvulusForeign body visualizationCT:Study of choice to help determine presence, location, cause, and severity of obstruction (partial vs. complete obstruction)Closed loop obstruction: distended, fluid-filled, C-shaped or U-shaped loop of bowel with prominent mesenteric vasculature converging on point of torsion/incarcerationBowel ischemia: intestinal pneumatosis and mesenteric changes (may not be detected in mild ischemia)Gallstone ileus should be considered in the presence of pneumobilia and small bowel obstruction; gallstones typically invisible on CT
  • Laboratory studies may help in the evaluation and management of associated dehydration and complications of intestinal obstruction.WBC count: Significant increases and left shift can indicate strangulation, sepsis, or ischemic bowel.Hematocrit: moderate rise associated with extracellular fluid lossRenal: urine specific gravity of 1.025 to 1.030 and increase in BUN and creatinine reflect degree of extracellular volume lossSerum lactate elevated in bowel strangulation and mesenteric ischemiaArterial blood gas:Metabolic alkalosis often a result of frequent emesisMetabolic acidosis can result from bowel ischemia directly related to obstruction or from associated severe dehydration.
  • Abdominal and chest radiographs to confirm diagnosis of intestinal obstruction:Distension of small bowel or colonAir-fluid levels (may be seen in ileus, gastroenteritis, constipation)Lack of colon gas (in small bowel obstruction)Free intraperitoneal air (strangulation with perforation)"Coffee bean sign" or "bent inner tube" appearance for colonic volvulusForeign body visualization
  • CT:Study of choice to help determine presence, location, cause, and severity of obstruction (partial vs. complete obstruction)Closed loop obstruction: distended, fluid-filled, C-shaped or U-shaped loop of bowel with prominent mesenteric vasculature converging on point of torsion/incarcerationBowel ischemia: intestinal pneumatosis and mesenteric changes (may not be detected in mild ischemia)Gallstone ileus should be considered in the presence of pneumobilia and small bowel obstruction; gallstones typically invisible on CT
  • Distension of small bowel or colon
  • Air-fluid levels (may be seen in ileus, gastroenteritis, constipation)
  • Lack of colon gas (in small bowel obstruction)
  • Free intraperitoneal air (strangulation with perforation)
  • "Coffee bean sign" or "bent inner tube" appearance for colonic volvulus
  • Foreign body visualization
  • Study of choice to help determine presence, location, cause, and severity of obstruction (partial vs. complete obstruction)
  • Closed loop obstruction: distended, fluid-filled, C-shaped or U-shaped loop of bowel with prominent mesenteric vasculature converging on point of torsion/incarceration
  • Bowel ischemia: intestinal pneumatosis and mesenteric changes (may not be detected in mild ischemia)
  • Gallstone ileus should be considered in the presence of pneumobilia and small bowel obstruction; gallstones typically invisible on CT
  • WBC count: Significant increases and left shift can indicate strangulation, sepsis, or ischemic bowel.
  • Hematocrit: moderate rise associated with extracellular fluid loss
  • Renal: urine specific gravity of 1.025 to 1.030 and increase in BUN and creatinine reflect degree of extracellular volume loss
  • Serum lactate elevated in bowel strangulation and mesenteric ischemia
  • Arterial blood gas:Metabolic alkalosis often a result of frequent emesisMetabolic acidosis can result from bowel ischemia directly related to obstruction or from associated severe dehydration.
  • Metabolic alkalosis often a result of frequent emesis
  • Metabolic acidosis can result from bowel ischemia directly related to obstruction or from associated severe dehydration.
  • Contrast studies:Water-soluble (Gastrografin) enema is useful for the diagnosis of colonic obstruction and may be therapeutic in reducing intussusception.Oral Gastrografin (preferred over barium) helps differentiate obstruction from ileus.Enteroclysis may identify the site of small bowel obstruction (rarely used).
  • Although not as helpful as CT, ultrasound may be used for pregnant patients or as a bedside test for the critically ill.
  • Water-soluble (Gastrografin) enema is useful for the diagnosis of colonic obstruction and may be therapeutic in reducing intussusception.
  • Oral Gastrografin (preferred over barium) helps differentiate obstruction from ileus.
  • Enteroclysis may identify the site of small bowel obstruction (rarely used).
  • Rigid proctoscopy: may be therapeutic in sigmoid volvulus
  • Flexible sigmoidoscopy/colonoscopy
  • Edema of mucosa
  • Hypersecretion
  • Necrosis

TREATMENT

  • Inpatient management is generally recommended.
  • Clinically stable patients may be treated conservatively with bowel rest, nasogastric suction, and IV fluid resuscitation. Use opioids with caution.
  • Consider surgery if obstruction does not resolve within 48 to 72 hours of initiation of conservative therapy or if the clinical situation merits immediate intervention.
  • Delay in surgery (4 or more days) for adhesive small bowel obstruction is associated with longer hospital stays and increased mortality (1)[A].
  • Immediate surgical exploration is warranted if any of the following are present:Signs concerning for sepsis or peritonitisConcern for intestinal ischemia/bowel necrosisSigns of bowel perforationIrreducible/strangulated hernia
  • Consider use of intraperitoneal prophylactic agents (Seprafilm or SurgiWrap) to prevent intra-abdominal adhesions.
  • Laparoscopy is a safe and effective means to reduce adhesive-related obstruction and may help minimize complications, length of stay (2)[B], and the rate of recurrent adhesive disease.
  • Surgical intervention is usually necessary for management of bowel obstruction in patients without prior abdominal surgeries.
  • Signs concerning for sepsis or peritonitis
  • Concern for intestinal ischemia/bowel necrosis
  • Signs of bowel perforation
  • Irreducible/strangulated hernia

GENERAL MEASURES

  • IV fluids
  • Nasogastric suction
  • Foley catheter

MEDICATION

ISSUES FOR REFERRAL

SURGERY/OTHER PROCEDURES

  • Operative timing is critical; correct electrolytes and volume before surgery if possible.
  • Surgical proceduresClosed bowel procedures: lysis of adhesions, and reduction of intussusception, volvulus, or incarcerated herniaEnterotomy for the removal of bezoars, foreign bodies, gallstonesResection of bowel for obstructing lesions, strangulated bowelIntestinal bypassColostomy or cecostomy, with or without mucous fistula, proximal to obstructionStricturoplasty for obstruction caused by Crohn diseaseEndoscopic relief of large bowel obstruction using a self-expandable stent is safe and effective for patients with malignant obstructions; can be used as a bridge to surgery or as palliation (3)[A]
  • Closed bowel procedures: lysis of adhesions, and reduction of intussusception, volvulus, or incarcerated hernia
  • Enterotomy for the removal of bezoars, foreign bodies, gallstones
  • Resection of bowel for obstructing lesions, strangulated bowel
  • Intestinal bypass
  • Colostomy or cecostomy, with or without mucous fistula, proximal to obstruction
  • Stricturoplasty for obstruction caused by Crohn disease
  • Endoscopic relief of large bowel obstruction using a self-expandable stent is safe and effective for patients with malignant obstructions; can be used as a bridge to surgery or as palliation (3)[A]

INPATIENT CONSIDERATIONS

ONGOING CARE

FOLLOW-UP RECOMMENDATIONS

  • Daily monitoring in hospital
  • Postoperative outpatient follow-up in 1 to 2 weeks

DIET

PROGNOSIS

  • Prognosis depends on the underlying etiology and general medical condition.
  • Mortality from intestinal obstruction ranges from <1% to >20% depending on etiology, bowel viability, and comorbid conditions.

COMPLICATIONS

  • Higher risk of subsequent obstruction
  • Slow return of bowel function
  • Sepsis
  • Bowel ischemia and necrosis

REFERENCES

ADDITIONAL READING

  • Andreyev HJ, Davidson SE, Gillespie C, et al. Practice guidance on the management of acute and chronic gastrointestinal problems arising as a result of treatment for cancer. Gut. 2012;61(2):179-192.
  • Arung W, Meurisse M, Detry O. Pathophysiology and prevention of postoperative peritoneal adhesions. World J Gastroenterol. 2011;17(41):4545-4553.
  • Harrison ME, Anderson MA, Appalaneni V, et al. The role of endoscopy in the management of patients with known and suspected colonic obstruction and pseudo-obstruction. Gastrointest Endosc. 2010;71(4):669-679.
  • Diaz JJJr, Bokhari F, Mowery NT, et al. Guidelines for management of small bowel obstruction. J Trauma. 2008;64(6):1651-1664.
  • Jackson PG, Raiji MT. Evaluation and management of intestinal obstruction. Am Fam Physician. 2011;83(2):159-165.
  • Kumar S, Wong PF, Leaper DJ. Intra-peritoneal prophylactic agents for preventing adhesions and adhesive intestinal obstruction after non-gynaecological abdominal surgery. Cochrane Database Syst Rev. 2009;(1):CD005080.
  • O'Connor DB, Winter DC. The role of laparoscopy in the management of acute small-bowel obstruction: a review of over 2,000 cases. Surg Endosc. 2012;26(1):12-17.

CODES

ICD10

  • K56.60 Unspecified intestinal obstruction
  • K56.41 Fecal impaction
  • K56.69 Other intestinal obstruction
  • Q41.9 Congen absence, atresia and stenosis of sm int, part unsp
  • K56.49 Other impaction of intestine
  • K56.2 Volvulus
  • K56.5 Intestinal adhesions w obst (postprocedural) (postinfection)

ICD9

  • 560.9 Unspecified intestinal obstruction
  • 560.32 Fecal impaction
  • 560.39 Other impaction of intestine
  • 751.1 Atresia and stenosis of small intestine
  • 560.2 Volvulus

SNOMED

  • Intestinal obstruction (disorder)
  • Fecal impaction (disorder)
  • Impaction of intestine (disorder)
  • Congenital absence, atresia and stenosis of small intestine
  • intestinal volvulus (disorder)
  • Primary chronic pseudo-obstruction of colon

CLINICAL PEARLS

  • 15-20% of patients with colorectal cancer present with colonic obstruction.
  • Initial management involves early surgical consultation, intravenous fluid and electrolyte management, nasogastric decompression, and Foley catheter placement to monitor fluid status.
  • Clinical history and plain films establish the diagnosis in most cases.
  • Surgical intervention is usually needed to treat bowel obstructions in patients without a history of prior abdominal surgeries.