Rosen & Barkin's 5-Minute Emergency Medicine Consult (289 page)

• Regardless of exact cause, gastric outlet obstruction characteristically leads to nausea and nonbilious vomiting
  
• Persistent vomiting may lead to dehydration, electrolyte and acid–base derangements
  
  • Chronic symptoms may lead to weight loss, malnutrition, failure to thrive
    
  • Hypokalemic, hypochloremic metabolic alkalosis is classic finding
    

DIAGNOSIS

• Symptoms may be intermittent until obstruction becomes complete
  
• Nausea and vomiting,
  usually
  nonbilious
  
• Abdominal pain, variable in character and often vague
  
• Early satiety and epigastric fullness
  
• Epigastric discomfort relieved with emesis
  
• Weight loss, failure to thrive
  

• Vital signs:
  
  • May be normal
    
  • Tachycardia, hypotension if volume depletion is significant
    
• Abdominal exam:
  
  • Variable amount of epigastric/abdominal distention
    
  • Tympanitic to auscultation
    
  • Succession splash >4 hr after eating
    
  • Digital rectal exam: Evaluate for occult blood
    
• Signs of dehydration in eyes, oral pharynx, mucous membranes, skin turgor
  
• Signs of malnutrition in chronic or late obstruction
  
• Weight loss when chronic and with malignancy
  

• Abdominal pain, nausea/vomiting: GI symptoms may be more vague/subtle in elderly patients
  
• If appropriate, consider other causes of symptoms (cardiac causes, neurologic causes)
  

• Idiopathic hypertrophic pyloric stenosis:
  
  • Most common cause in pediatric population
    
  • “Typical” patient is male (Caucasian and US-born Asians more common)
    
  • Usually 2–8 wk old but may be diagnosed as early as 1st wk and up to 3 mo of age
    
  • Initially intermittent, nonprojectile, postprandial vomiting, which progresses to projectile, nonbilious vomiting
    
  • A midepigastric peristaltic wave occurring prior to vomiting may be visible on exam
    
  • Epigastric “olive” mass may be palpable in 80–90% of patients
    

Careful history and physical exam

• CBC:
  
  • Anemia if malignancy or GI blood loss
    
  • High hematocrit indicating hemoconcentration
    
• Electrolytes, BUN/creatinine, glucose:
  
  • Hypokalemia
    
  • Hypochloremic metabolic alkalosis
    
  • Hypoglycemia
    
  • Prerenal azotemia
    
• Urinalysis
  
• Amylase/lipase
  
• Liver profile, if malignancy suspected
  
• H. pylori
  , if PUD suspected
  

• Plain abdominal radiographs (obstructive series):
  
  • Often nondiagnostic
    
  • Dilated stomach or absence of air in bowel distally may be suggestive
    
• Abdominal US in pediatric patients:
  
  • No ionizing radiation
    
  • Elongated hypertrophic pyloric sphincter
    
• Abdominal CTs are often very helpful for detecting neoplastic, intraluminal, and extraluminal causes of obstruction.
  
  • Likely to be most commonly used modality in adults
    
  • Radiation load is especially undesirable in pediatric population; ultrasound and fluoroscopic UGI series are preferred initial approaches
    

• Upper GI series:
  
  • To demonstrate site and character of obstruction
    
  • “String sign,” “double track sign,” “beak sign,” “shoulder sign” are characteristic findings in pyloric stenosis
    
• Upper endoscopy:
  
  • To visualize gastric interior, gastric outlet, proximal duodenum
    

• Proximal bowel obstruction
  
• Exacerbation of PUD
  
• Gastroenteritis
  
• Cholelithiasis
  
• Cholecystitis
  
• Acute pancreatitis
  
• Diabetic gastroparesis
  
• Psychogenic vomiting
  

TREATMENT

• Vital signs, airway stabilization, oxygen administration, IV access
  
• Fluid resuscitation if dehydrated, vomiting
  

• 0.9% NS IV fluid resuscitation significant volume losses:
  
  • Adults: 1 L bolus
    
  • Peds: 20 mL/kg bolus
    
• Correction of electrolyte abnormalities, especially hypokalemia
  

• Nasogastric tube (NGT)
  
• Foley catheter to monitor urine output
  
• Surgical consultation/intervention:
  
  • Endoscopic balloon dilatation of benign strictures
    
  • Enteral stent placement (malignant causes)
    
  • Gastrojejunostomy (malignant causes)
    
  • Vagotomy and antrectomy or pyloroplasty or gastrojejunostomy or other variation (benign causes)
    

• Famotidine: Adults: 20 mg (peds: 0.6–0.8 mg/kg/24 h div. q6–8h) IV q12h
  or
  
• Ranitidine: 50 mg (peds: 2–4 mg/kg/24 h div. q6–8h) IV q8h
  
• Pantoprazole: Adults: 40 mg IV (also
  H. pylori
  treatment as needed)
  

FOLLOW-UP

Most patients with gastric outlet obstruction will be admitted for fluid resuscitation, electrolyte repletion, gastroenterologic, and surgical evaluation.

Rarely, patients may be considered for discharge if:

• Symptoms of abdominal pain, vomiting have resolved
  
• Evaluated and cleared by surgeon or gastroenterologist during presentation
  
• Lab parameters, imaging, and patient’s volume status are normal
  

Surgical and gastroenterology consultations

Any discharged patient should follow up with surgeon and/or gastroenterologist:

• Specific instructions to return if symptoms recur
  

• Misdiagnosing symptoms of gastric outlet obstruction as gastroenteritis
  
• Failure to appreciate limitations of plain radiographs in diagnosing this condition
  
• Failure to consider gastric outlet obstruction and malignancy in patient with epigastric pain and vomiting
  
• Failure to adequately fluid resuscitation of patients, especially elderly or pediatric patients
  

• Dada SA, Fuhrman GM. Miscellaneous Disorders and their management in gastric surgery: Volvulus, carcinoid, lymphoma, gastric varices, and gastric outlet obstruction.
  Surg Clin North Am.
  2011;91:1123–1130.
  
• Kim JH, Shin JH, Song HY. Benign strictures of the esophagus and gastric outlet: Interventional management.
  Korean J Radiol
  . 2010;11(5);497–506.
  
• Otjen JP, Iyer RS, Phillips GS, et al. Usual and unusual causes of pediatric gastric outlet obstruction.
  Pediatr Radiol
  . 2012;42:728–737.
  
• Shone DN, Nikoomanesh P, Smith-Meek MM, et al. Malignancy is the most common cause of gastric outlet obstruction in the era of H
  ₂
  blockers.
  Am J Gastroenterol
  . 1995;90:1769–1770.
  

See Also (Topic, Algorithm, Electronic Media Element)

• Abdominal Pain
  
• Bowel Obstruction
  
• Pyloric Stenosis
  
• Vomiting
  

CODES

537.0 Acquired hypertrophic pyloric stenosis

BASICS