Signs and Symptoms
History
- Vomiting:
- Gradual onset, usually beginning at around 3-6 wk of age; rarely after 12 wk of age
- Progressive, usually becoming projectile
- Nonbilious
- May be blood tinged (secondary to esophagitis, gastritis, gastric ulceration)
- Progressively worsening
- Postprand ial
- Constipation or small amount of stools
- “Lean and hungry” infant early in course; dehydrated and uninterested in feeding late in course; failure to thrive
- Variable dehydration and wasting depending on duration of symptoms
- Jaundice in 8% of children
- Adult presents with vomiting, anorexia, early satiety, and epigastric pain
Physical Exam
- Often normal unless a relaxed abdomen
- May feel olive-shaped mass at lateral margin of the right rectus abdominis muscle in the right upper quadrant (80% of patients), often after vomiting:
- Best felt immediately after vomiting or after the stomach is emptied via gastric suction as the dilated body of the stomach overlies the pylorus
- Represents the hypertrophied pylorus:
- Helps confirm diagnosis
- Peristaltic waves moving from the left to right in the left upper quadrant, seen best after feeding or just prior to vomiting
Essential Workup
If “olive” palpable, further diagnostic evaluation may be unnecessary and surgical consultation should be sought; otherwise, imaging studies are indicated
Diagnostic Tests & Interpretation
Lab
- Electrolytes, BUN/creatinine, glucose:
- Hypokalemic, hypochloremic metabolic alkalosis
- Normal electrolytes do not exclude the diagnosis
- Bilirubin elevated, usually unconjugated
- CBC, if blood in emesis
- Urinalysis for assessment of hydration
Imaging
- Abdominal US:
- Study of choice
- US diagnosis hinges on identification and measurement of pyloric muscle mass (3-mm ring thickness, 1.5 cm pylorus channel or muscle length, and 10-14 mm pylorus diameter) and observation of fluid movement through the pylorus
- Positive predictive value approaches 100%; 19% false negatives
- Serial US for equivocal or negative study
- Upper GI series:
- String sign representing contrast passing through a narrowed gastric outlet
- 95% accurate
- Used if US not diagnostic
- Remove contrast from the stomach after the study to prevent aspiration
- Supine abdominal film:
- Not diagnostic; rarely helpful
- Dilated stomach and no air distal to the pylorus
- Most useful with other views to begin evaluation for other abdominal pathology
Differential Diagnosis
- GI anatomic/functional disorder:
- Gastroesophageal reflux
- Hiatal hernia
- Obstruction/atresia
- Gastric or duodenal web
- Infection:
- Metabolic:
- Adrenal insufficiency
- Inborn error of metabolism
- Feeding problems:
- Psychosocial: Poor maternal interaction or stress
- Chalasia
- Formula intolerance
- Overfeeding
- Drug withdrawal
- Increased intracranial pressure
Prehospital
Fluid resuscitation if significant volume deficit
Initial Stabilization/Therapy
- IV access
- Rapid bedside glucose test to exclude hypoglycemia
- Correct volume deficit with 20 mL/kg bolus of 0.9% normal saline IV; may repeat
ED Treatment/Procedures
- Correct electrolyte abnormalities
- Hydrate with dextrose-containing solution after fluid resuscitation at 1-1.5× maintenance rate:
- Add potassium after ensuring adequate urine output
- Insert nasogastric tube to decompress the stomach
- Restrict oral intake
- Consult pediatric surgeon for pyloromyotomy
- Atropine has been used for management in children with major concurrent disease in whom surgery would be high risk
- Adult: Proton pump antagonist (lansoprazole or omeprazole)
Medication
Adults
- Lansoprazole: 30 mg daily PO
- Omeprazole: 20 mg daily PO
Disposition
Admission Criteria
- All pediatric patients should be admitted to the hospital for rehydration and surgical correction with either an umbilical pyloromyotomy or laparoscopic pyloromyotomy
- Adult patients: Admit as necessary for rehydration; may be scheduled for elective pyloromyotomy if proton pump inhibitors fail to improve this condition
Issues for Referral
Surgical consultation concurrent with correction of electrolytes and fluid deficits
Follow-up Recommendations
Follow growth pattern after surgery
ICD9
537.0 Acquired hypertrophic pyloric stenosis
ICD10
K31.1 Adult hypertrophic pyloric stenosis
SNOMED
367403001 Pyloric stenosis (disorder)
13483000 Acquired hypertrophic pyloric stenosis
266438007 Adult hypertrophic pyloric stenosis (disorder)
333952004 Acquired nonhypertrophic constriction of pylorus (disorder)