Rosen & Barkin's 5-Minute Emergency Medicine Consult (111 page)

• Previous surgery, malignancy, hernias, colonoscopy history, significant family history
  
• Abdominal pain:
  
  • Intermittent when early
    
  • Symptoms may be vague in elderly or altered patients
    
  • Constant with strangulated obstruction
    
• Vomiting:
  
  • Bile-stained emesis with proximal obstruction
    
  • Feculent emesis with distal obstruction
    
• Obstipation, constipation, diarrhea
  
• Stool caliber changes, weight loss
  

• Vital signs:
  
  • Tachycardia, hypotension with significant volume depletion
    
  • Fever with strangulation or perforation
    
  • Hypothermia with sepsis
    
• Abdominal exam:
  
  • Distention
    
  • Variable tenderness, often diffuse
    
  • Hyperactive and high-pitched bowel sounds when early; hypoactive when late
    
  • Consider ischemic or gangrenous bowel if pain out of proportion to exam.
    
  • Peritoneal signs indicate strangulation or perforation.
    
• Hernia (ventral, inguinal, femoral)
  
• Digital rectal exam:
  
  • Rectal mass
    
  • Blood in stool, gross or occult
    

• Abdominal pain variable in elderly, may be vague
  
• Nausea/vomiting and abdominal pain are common symptoms in elderly patients with acute myocardial infarctions:
  
  • Abdominal distention, obstipation, and colicky pain suggest GI cause.
    

• Intussusception:
  
  • Leading cause of intestinal obstruction in infants
    
  • Most common between 3 and 12 mo of age
    
• Incarcerated inguinal/umbilical hernia
  
• Malrotation with volvulus:
  
  • Can occur as early as 3–7 days of age
    
  • “Double bubble” sign seen on plain radiograph owing to partial obstruction of duodenum, resulting in air in stomach and in 1st part of duodenum
    
• Pyloric stenosis:
  
  • Progressive, projectile, nonbilious postprandial vomiting
    
  • Male/female ratio: 5:1 incidence
    
  • Onset usually 2–5 wk of age
    
• Other causes include duodenal atresia, Hirschsprung, and imperforate anus.
  

Careful history and physical exam

• CBC:
  
  • Leukocytosis common
    
• Electrolytes, BUN/creatinine, glucose:
  
  • Hypokalemia
    
  • Hypochloremic metabolic alkalosis
    
  • Prerenal azotemia
    
• Lactate
  
• Amylase/lipase
  
• Liver enzymes/function to exclude hepatic/biliary pathology
  
• Stool heme test
  
• Urinalysis
  
• Type and crossmatch
  
• PT/PTT
  
• ECG in patients at risk of coronary artery disease
  

• Upright CXR:
  
  • Evaluate for pulmonary pathology.
    
  • Check for free air beneath diaphragm.
    
• Plain abdominal radiographs, supine and upright (75% sensitivity; 53% specificity):
  
  • Distended loops of bowel (normal small bowel <3 cm in diameter)
    
  • Distended cecum >13 cm indicates potential for perforation.
    
  • Air–fluid levels
    
  • “String of pearls” sign if small bowel loops nearly completely fluid filled
    
  • Less helpful for distinguishing strangulation
    
• Abdominal CT:
  
  • Sensitivity:
    
    • 90% for SBO; 91% for LBO
      
  • Detects neoplastic causes and stages malignancy
    
  • Effective in defining location of obstruction
    
  • More helpful than plain radiographs in identifying early strangulation (with IV contrast)
    
  • Exclude other incidental findings/causes
    
  • Has decreased use of contrast enemas due to ease of use
    
• MRI:
  
  • Sensitivity approached that of CT
    
  • Availability variable
    
• US:
  
  • More sensitive and specific than plain films for SBO but not as accurate as CT
    

Upper GI/barium enemas/endoscopy:

• If carcinoma or mass lesion suspected as cause
  
• Use decreased with availability of CT scan
  
• May be painful or difficult in sick patients
  

• Paralytic ileus
  
• Pseudo-obstruction (Ogilvie)
  
• Perforated ulcer
  
• Pancreatitis
  
• Cholecystitis
  
• Colitis
  
• Mesenteric ischemia
  

TREATMENT

Establish IV access for patients with dehydration, vomiting, or significant abdominal pain.

• ABCs
  
• 0.9% normal saline (NS) or lactated ringers (LR) IV fluid resuscitation for significant volume depletion and strangulated or perforated bowel:
  
  • Adults: 1 L bolus
    
  • Peds: 20 mL/kg bolus
    
• Correct electrolyte abnormalities, especially hypokalemia.
  

• IV fluids (isotonic saline or lactated Ringer’s)
  
• Nasogastric tube (NGT)
  
• Foley catheter to monitor urine output
  
• Surgical consultation
  
• Antibiotics for suspected strangulated/perforated bowel:
  
  • Antibiotic choices should cover gram-negative aerobic and anaerobic organisms:
    
• Analgesics
  
• Antiemetics
  
• Treat underlying etiology, appropriate steroids for inflammatory bowel disease, radiation enteritis
  

• Antibiotic choices (broad spectrum, for suspected ischemia):
  
  • Combination therapy:
    
    • Metronidazole (Flagyl): 1 g IV, then 500 mg IV q6h (peds: 7.5–30 mg/kg/24h IV div. q6–8h)
      
    • Ciprofloxacin (Cipro): 400 mg IV q12h
      
    • Ceftriaxone (Rocephin): 1–2 g (peds: 25–75 mg/kg/d IV up to 2 g div. q12–24h) IV q24h
      
  • Single therapy:
    
    • Piperacillin–tazobactam (Zosyn): 3.375 g (peds: 150–400 mg/kg/24h IV div. q6–8h) IV q4–6h
      
    • Ampicillin–sulbactam (Unasyn): 1.5–3 g (peds: 100–400 mg/kg/24h IV div. q6h) IV q6h
      
    • Meropenem (Merrem): Adult: 1 g (peds: 60–120 mg/kg/24h IV q8h) IV q8h
      
    • Imipenem–cilastatin (Primaxin): 250–1,000 mg (peds: 50–100 mg/kg/24h IV q6–12h) IV q6–8h
      
• Analgesics:
  
  • Morphine: 2–10 mg/dose (peds: 0.1–0.2 mg/kg IV/IM/SC q2–4h) IV/IM/SC q2–6h PRN
    
• Antiemetics:
  
  • Ondansetron (Zofran): 4 mg (peds: 0.1 mg/kg IV div. q8h) IV q4–8h PRN
    
  • Promethazine (Phenergan): 12.5–25 mg (peds: >2 yr: 0.25–1 mg/kg/d IV/IM/PR div. q4–6h PRN) IV/IM/SC q4h
    

FOLLOW-UP

All patients with suspected/confirmed intestinal obstruction should be admitted with early surgical consultation.

Normal lab/radiology results with resolution of symptoms and no further suspicion for intestinal obstruction.

Surgery consult for patients with suspected bowel obstruction

Discharged patients:

• Normal lab and radiologic studies
  
• Timely appointment for re-evaluation
  
• Explicit instructions detailing signs/symptoms to return to emergency department
  

• Carefully examine patient with history of vomiting for incarcerated hernias.
  
• Failure to diagnose strangulated bowel obstruction:
  
  • Symptoms potentially vague in very old and very young and in altered patients
    
• Failure to adequately replete fluid losses and electrolyte imbalances
  

• Batke M. Cappell MS. Adynamic ileus and acute colonic pseudo-obstruction.
  Med Clin North Am
  . 2008;92(3):649–670.
  
• Diaz JJ Jr, Bokhari F, Mowery NT, et al. Guidelines for management of small bowel obstruction.
  J Trauma
  . 2008;64(6):1651–1654.
  
• Hopkins C. Large-bowel obstruction workup. Available at
  http://emedicine.medscape.com/article/774045-workup#aw2aab6b5b5aa
  . Updated Nov 11, 2011. Accessed February 2013.
  
• Noble BA. Small-bowel obstruction. Available at
  http://emedicine.medscape.com/article/774140-overview
  . Updated Oct 5, 2011. Accessed February 2013.
  
• Walker GM, Raine PA. Bilious vomiting in the newborn: How often is further investigation undertaken?
  J Pediatr Surg
  . 2007;42(4):714–716.
  

See Also (Topic, Algorithm, Electronic Media Element)

• Abdominal Pain
  
• Gastric Outlet Obstruction
  
• Pyloric Stenosis
  
• Vomiting
  

CODES