Updated: 7/15/2019

Pyloric Stenosis

Topic
Review Topic
0
0
Questions
5
0
0
Evidence
5
0
0
Videos
1
https://upload.medbullets.com/topic/120609/images/pyloric_stenosis.jpg
Snapshot
  • UltrasoundA 6-week-old first-born baby boy presents with projectile vomiting after feedings over the last 24 hours. Mom says that he enjoys feeding, and even after he vomits, he appears eager and hungry. On physical exam, you palpate an olive-shaped mass in the epigastric region. Labs show blood pH 7.47 and potassium of 3.2 mmol/L.
Overview
 
Introduction
  • Congenital hypertrophy of the pyloric sphincter 
  • Prevents stomach from emptying contents into intestinal tract 
    • "gastric outlet obstruction"
  • Risk factors
    • maternal history of pyloric stenosis
    • erythromycin use
  • Associated with transesophageal fistulas
  • Epidemiology
    • 1:500 births 
    • males > females
    • more common in first-borns
    • uncommon in children > 6 months old, most common within first 12 weeks of life
Presentation
  • Symptoms
    • infants feed well for first 2-3 weeks of life
    • presents with non-bilious vomiting after most or every feeding 
    • progresses to projectile vomiting at 2 weeks-2 months of life
    • can lead to severe malnutrition/dehydration
    • may experience other symptoms including
      • belching
      • abdominal pain
      • constant hunger
      • weight loss/failure to thrive
  • Physical exam
    • palpable epigastric olive-shaped mass
      • pathognomonic for the disorder
    • visible peristaltic waves over the gastrum
    • may have swollen abdomen indicated of starvation state

Evaluation
  • Electrolytes 
    • metabolic alkalosis
    • hypokalemia/hypochloremia
      • secondary to recurrent emesis
  • Barium studies
    • may show narrow pyloric channel
    • "string sign" or "pyloric beak"
  • Ultrasound
    • hypertrophic pylorus may be observed
Differential
  • Hiatal hernia, duodenal atresia, volvulus, meconium ileus, GERD, gastroenteritis, tracheoesophageal fistula

Treatment
  • Medical management
    • Hydration via IV fluids
      • indicated in all cases
    • Normalize acid-base/electrolyte abnormalities
      • potassium replacement is key
      • indicated in all cases
  • Surgical intervention
    • pyloromyotomy
      • indicated for surgical correction of defect
Prognosis, Prevention, and Complications
  • Prognosis
    • very good to excellent
    • surgery relieves symptoms and child is usually eating within hours of surgery
  • Prevention
    • there are no preventive measures available at this time
  • Complications
    • failure to thrive
High Yield
  • A newborn boy presents with projectile vomiting and is always hungry to eat more after vomiting.  The vomit is non-bilious, and an olive shaped mass is palpable in the patients abdomen.  The patient has been treated with erythromycin for an infection.
    • next best step in management: IV fluids and correct electrolytes (or order a complete metabolic panel)
    • best initial test: ultrasound with a target shape lesion
    • most accurate test: ultrasound
    • treatment: pyloromyotomy
 

Please rate topic.

Average 5.0 of 2 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Questions (5)
Lab Values
Blood, Plasma, Serum Reference Range
ALT 8-20 U/L
Amylase, serum 25-125 U/L
AST 8-20 U/L
Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca2+) 8.4-10.2 mg/dL
Cholesterol, serum Rec: < 200 mg/dL
Cortisol, serum 0800 h: 5-23 μg/dL //1600 h:
3-15 μg/dL
2000 h: ≤ 50% of 0800 h
Creatine kinase, serum Male: 25-90 U/L
Female: 10-70 U/L
Creatinine, serum 0.6-1.2 mg/dL
Electrolytes, serum  
Sodium (Na+) 136-145 mEq/L
Chloride (Cl-) 95-105 mEq/L
Potassium (K+) 3.5-5.0 mEq/L
Bicarbonate (HCO3-) 22-28 mEq/L
Magnesium (Mg2+) 1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)  
24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL
Ferritin, serum Male: 15-200 ng/mL
Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL
Female: premenopause: 4-30 mIU/mL
midcycle peak: 10-90 mIU/mL
postmenopause: 40-250
pH 7.35-7.45
PCO2 33-45 mmHg
PO2 75-105 mmHg
Glucose, serum Fasting: 70-110 mg/dL
2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation Fasting: <5 ng/mL
Provocative stimuli: > 7ng/mL
Immunoglobulins, serum  
IgA 76-390 mg/dL
IgE 0-380 IU/mL
IgG 650-1500 mg/dL
IgM 40-345 mg/dL
Iron 50-170 μg/dL
Lactate dehydrogenase, serum 45-90 U/L
Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL
Female: follicular phase: 5-30 mIU/mL
midcycle: 75-150 mIU/mL
postmenopause 30-200 mIU/mL
Osmolality, serum 275-295 mOsmol/kd H2O
Parathyroid hormone, serume, N-terminal 230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L
Phosphorus (inorganic), serum 3.0-4.5 mg/dL
Prolactin, serum (hPRL) < 20 ng/mL
Proteins, serum  
Total (recumbent) 6.0-7.8 g/dL
Albumin 3.5-5.5 g/dL
Globulin 2.3-3.5 g/dL
Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL
Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h
Thyroxine (T4), serum 5-12 μg/dL
Triglycerides, serum 35-160 mg/dL
Triiodothyronine (T3), serum (RIA) 115-190 ng/dL
Triiodothyronine (T3) resin uptake 25%-35%
Urea nitrogen, serum 7-18 mg/dL
Uric acid, serum 3.0-8.2 mg/dL
Hematologic Reference Range
Bleeding time 2-7 minutes
Erythrocyte count Male: 4.3-5.9 million/mm3
Female: 3.5-5.5 million mm3
Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/h
Female: 0-20 mm/h
Hematocrit Male: 41%-53%
Female: 36%-46%
Hemoglobin A1c ≤ 6 %
Hemoglobin, blood Male: 13.5-17.5 g/dL
Female: 12.0-16.0 g/dL
Hemoglobin, plasma 1-4 mg/dL
Leukocyte count and differential  
Leukocyte count 4,500-11,000/mm3
Segmented neutrophils 54%-62%
Bands 3%-5%
Eosinophils 1%-3%
Basophils 0%-0.75%
Lymphocytes 25%-33%
Monocytes 3%-7%
Mean corpuscular hemoglobin 25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration 31%-36% Hb/cell
Mean corpuscular volume 80-100 μm3
Partial thromboplastin time (activated) 25-40 seconds
Platelet count 150,000-400,000/mm3
Prothrombin time 11-15 seconds
Reticulocyte count 0.5%-1.5% of red cells
Thrombin time < 2 seconds deviation from control
Volume  
Plasma Male: 25-43 mL/kg
Female: 28-45 mL/kg
Red cell Male: 20-36 mL/kg
Female: 19-31 mL/kg
Cerebrospinal Fluid Reference Range
Cell count 0-5/mm3
Chloride 118-132 mEq/L
Gamma globulin 3%-12% total proteins
Glucose 40-70 mg/dL
Pressure 70-180 mm H2O
Proteins, total < 40 mg/dL
Sweat Reference Range
Chloride 0-35 mmol/L
Urine  
Calcium 100-300 mg/24 h
Chloride Varies with intake
Creatinine clearance Male: 97-137 mL/min
Female: 88-128 mL/min
Estriol, total (in pregnancy)  
30 wks 6-18 mg/24 h
35 wks 9-28 mg/24 h
40 wks 13-42 mg/24 h
17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 h
Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total Male: 8-20 mg/24 h
Female: 6-15 mg/24 h
Osmolality 50-1400 mOsmol/kg H2O
Oxalate 8-40 μg/mL
Potassium Varies with diet
Proteins, total < 150 mg/24 h
Sodium Varies with diet
Uric acid Varies with diet
Body Mass Index (BMI) Adult: 19-25 kg/m2
Calculator

You have 100% on this question.
Just skip this one for now.

(M2.PD.13) A 5-week-old boy presents to the emergency department because of feeding problems. His parents inform the physician that their child has been vomiting after many of his feeds for the past week. They state that this is a new issue. His temperature is 97.6°F (36.4°C), blood pressure is 74/50 mmHg, pulse is 170/min, respirations are 15/min, and oxygen saturation is 99% on room air. Ultrasound of the abdomen is performed as seen in Figure A. Which of the following changes in Figure B is most likely to be seen in this patient? Review Topic

QID: 104287
FIGURES:
Type in at least one full word to see suggestions list
1

A

0%

(0/2)

2

B

50%

(1/2)

3

C

0%

(0/2)

4

D

50%

(1/2)

5

E

0%

(0/2)

M2

Select Answer to see Preferred Response

SUBMIT RESPONSE 2
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

You have 100% on this question.
Just skip this one for now.

(M2.PD.4688) A 5-week-old male infant is brought to the Emergency Department with the complaint of vomiting. His parents state he has been unable to keep normal feedings down for the past week and now has projectile non-bilious vomiting after each meal. He was given a short course of oral erythromycin at 4 days of life for suspected bacterial conjunctivitis. Physical examination is significant for sunken fontanelles and dry mucous membranes. A palpable, ball shaped mass is noted just to the right of the epigastrum. Which of the following conditions is most likely in this patient? Review Topic

QID: 107551
Type in at least one full word to see suggestions list
1

Gastroesophageal reflux

0%

(0/0)

2

Hypertrophic pyloric stenosis

0%

(0/0)

3

Milk-protein allergy

0%

(0/0)

4

Midgut volvulus

0%

(0/0)

5

Intussusception

0%

(0/0)

M2

Select Answer to see Preferred Response

SUBMIT RESPONSE 2

You have 100% on this question.
Just skip this one for now.

(M2.PD.4694) A 3-week-old boy has non-bilious projectile vomiting that occurred after feeding. After vomiting, the infant is still hungry. The infant appears dehydrated and malnourished. A firm, “olive-like” mass of about 1.5 cm in diameter is palpated in the right upper quadrant, by the lateral edge of the rectus abdominus muscle. On laboratory testing, the infant is found to have a hypochloremic, hypokalemic metabolic alkalosis. Which of the following is most likely the cause of this patient’s symptoms? Review Topic

QID: 107693
Type in at least one full word to see suggestions list
1

Intussusception

0%

(0/0)

2

Duodenal atresia

0%

(0/0)

3

Hypertrophy of the pylorus muscle

0%

(0/0)

4

Aganglionic colon segment

0%

(0/0)

5

Achalasia

0%

(0/0)

M2

Select Answer to see Preferred Response

SUBMIT RESPONSE 3
ARTICLES (5)
VIDEOS (1)
Topic COMMENTS (16)
Private Note