Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Epidemiology + • 0.1-0.4% incidence• 7% incidence among children of affected parent• 4:1 ratio male:female• Higher incidence in first born +++ Symptoms and Signs + • Nonbilious postprandial emesis 2-12 weeks of life becoming progressively projectile• Palpable pylorus in right upper quadrant or epigastric region ("olive")• Visible or palpable gastric peristaltic waves +++ Laboratory Findings + • Transient unconjugated hyperbilirubinemia in 1-2% of cases• Hypokalemic, hypochloremic, metabolic alkalosis +++ Imaging Findings + • US: Shows hypertrophic pylorus, 95% sensitive• Upper GI: Shows narrowed and elongated pylorus, 95% sensitive + • Repeated nonbilious vomiting in early infancy may be due to the following:-Overfeeding-Intracranial lesions-Pylorospasm-Antral web-Gastroesophageal reflux-Pyloric duplication-Duodenal stenosis-Malrotation of the bowel-Adrenal insufficiency + • History and physical exam• Serum electrolytes• Abdominal x-ray• US of abdomen if diagnosis in doubt• Upper GI if diagnosis still in doubt +++ Surgery + • Laparoscopic or open pyloromyotomy +++ Indications + • Normalization of serum electrolytes• Persistent vomiting +++ Medications + • Volume resuscitation and correction of chloride to at least 90 mEq/L and CO2 to less than 30 mEq/L +++ Treatment Monitoring + • Serum electrolytes before surgery +++ Complications + • Duodenal or gastric injury• Incomplete myotomy (recurrent gastric outlet obstruction) +++ Prognosis + • Excellent +++ References ++Aspelund G. Langer JC. Current management of hypertrophic pyloric stenosis. Seminars in Pediatric Surgery 2007. 16(1):27-33. [PubMed: 17210480] Your MyAccess profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth