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Pyloric Stenosis
Aka: Pyloric Stenosis, Hypertrophic Pyloric Stenosis, Pyloric Stenosis Ultrasound, Infantile Hypertrophic Pyloric Stenosis, Congenital Stricture of the Pylorus
- See Also
- Infant with Vomiting
- Epidemiology
- Ages 3-6 weeks old (mean 3 weeks, up to 12 weeks of age)
- Pathophysiology
- Hypertrophy of pylorus of the Stomach causing a gastric outlet obstruction
- Risk factors
- Family History of Pyloric Stenosis (especially northern european)
- Male gender (4 times more common than in girls)
- Other possible risk factors
- Bottle Feeding (Formula Feeding)
- Prematurity
- Maternal Tobacco Abuse
- Maternal Hyperthyroidism
- Macrolide antibiotic use in the first 2 weeks of life
- Symptoms: Vomiting
- Non-Bilious Vomiting that is more forceful than Spitting Up
- Starts intermittently
- Progressively increases in frequency and severity
- Infant remains hungry despite Vomiting
- Projectile Vomiting in up to 70% of cases
- Signs
- Typically, otherwise well appearing infant with benign Abdomen
- Palpable swelling ("olive") present in >60% of cases in past when delayed presentation was common
- In 2016 olive is rare due to early presentations
- Inferior to xiphoid process and inferior or deep to left liver edge
- Labs
- Basic metabolic panel
- Hypochloremic hypokalemic Metabolic Alkalosis
- Rarely seen due to early presentations in U.S.
- Other findings
- Hyponatremia
- Hypoglycemia
- Increased Renal Function tests (Serum Creatinine, Blood Urea Nitrogen)
- Imaging: Pyloric Ultrasound
- Technique
- Linear probe in subxiphoid location, horizontal probe
- Look for gastric rugae, smooth outer serosal surface, slightly thicker wall
- Trace the outer surface of the Stomach down to the pylorus and duodenum
- Duodenal wall is much thinner than pylorus
- Diagnosis
- Thickened and elongated pylorus
- Pylorus wall thickness >3 mm
- Pylorus diameter >13 mm
- Pylorus length >15 mm (variable)
- No relaxation
- No fluid passage within channel
- May see very minimal flow (string sign)
- Efficacy
- Test Sensitivity and Test Specificity approach 100%
- Differential Diagnosis
- See Vomiting Causes in Children
- Pediatric Reflux
- Milk Protein Intolerance
- Intestinal Malrotation
- Small Bowel Obstruction
- Complications
- Pediatric Dehydration
- Hypochloremic hypokalemic Metabolic Alkalosis
- Rarely seen due to early presentations in U.S.
- Management
- Correct fluid and Electrolyte abnormalities
- Risk of postoperative apnea if not corrected
- Surgery (pyloromyotomy)
- Loosens pyloric Muscle
- Resources
- Pyloric Stenosis Ultrasound
- https://vimeo.com/156797541
- References
- Bukata (2013) Pediatric Emergencies, EM Bootcamp, CEME
- Nazer (2013) Pediatric Hypertrophic Pyloric Stenosis, EMedicine
- http://emedicine.medscape.com/article/929829-overview#showall
- Nirappil (2021) Crit Dec Emerg Med 35(8):12-3