Ver el código de «Pyloric stenosis»

==Background==
*More common in males (5:1) & firstborn children (30%)
*Symptoms usually begin between 3-6 weeks of age, rarely after 12 weeks
*The main diagnostic criterion is a measurement of more than 3 mm in thickness of the muscular layer.<ref>Dias, S et al Insights Imaging. 2012 Jun; 3(3): 247–250.</ref> 
*Abnormal elongation of the canal is characterised as greater than 17 mm in length .<ref>Teele RL, Smith EH. Ultrasound in the diagnosis of idiopathic hypertrophic pyloric stenosis. N Engl J Med. 1977 May 19. 296(20):1149-50.</ref><ref>Sargent SK, Foote SL, Mooney DP, Shorter NA. The posterior approach to pyloric sonography. Pediatr Radiol. 2000 Apr. 30(4):256-7</ref>

==Clinical Features==
*Immediate post-prandial, non-bilious, often projectile vomiting, but desires to feed ("hungry vomiter")
*Palpable mass in in RUQ to epigastric region, occassionally may see peristaltic waves

==Differential Diagnosis==
{{Pediatric abdominal pain DDX}}

==Evaluation==
*Labs may show [[hypokalemia]] and hypochloremic [[metabolic alkalosis]]

===Imaging===
''Primary test of choice''
*Ultrasound: thickened (>3 mm) and elongated (>17 mm) pylorus ~ 95% Sn/Sp<ref>Rohrschneider WK, Mittnacht H, Darge K, Tröger J. Pyloric muscle in asymptomatic infants: sonographic evaluation and discrimination from idiopathic hypertrophic pyloric stenosis. Pediatr Radiol. 1998 Jun;28(6):429-34.</ref>

''Other tests that may show findings''
*[[Abdominal x-ray]]: may show large stomach bubble
*Upper GI: string sign (narrowed pyloric lumen), double track sign (duplicated mucosa), beak sign (abnormality of pyloric opening)

==Management==
*[[IVF]]
**Normal electrolytes and no evidence of dehydration
***5% dextrose with 0.25% NaCl and 2 meq KCl per 100 mL
**Moderate or severe dehydration
***Higher NaCl concentrations (0.5% to normal saline) and higher rates of administration (1.5 to 2 times maintenance)
*Nasogastric tube
*Surgery
**Can be delayed 24-36 hr to rehydrate infant and correct electrolytes
**Ensure correction of bicarbonate level, as it may be a hypoventilation risk

===Precautions===
*Ensure that kidneys are functional prior to giving [[potassium]] 
*Do not give lactated ringers
**May lead to worsening alkalosis > apnea in infants

==Disposition==
*Admission

==See Also==
*[[Abdominal Pain (Peds)]]

==References==
<references/>
[[Category:Pediatrics]]
[[Category:GI]]