15: Two siblings: 4-year-old male and 8- week-old male with vomiting Flashcards
Transmission of Viral Gastroenteritis
- at home
- at daycare
- young infants at risk
Electrolyte Abnormalities in Pyloric Stenosis
A hypochloremic, hypokalemic metabolic alkalosis is one of the hallmarks of pyloric stenosis.
Fluid Therapy for Severe Dehydration
The primary recommended mode of therapy for severe dehydration is to provide volume restoration via IV bolus therapy with an isotonic saline solution.
- -Repeated boluses of normal saline or lactacted Ringers solution, in 10-20 ml/kg aliquots, are given (reassessing after each bolus) until the patient has improved to only mild dehydration or normal fluid status.
- -Rehydration can then be completed either orally or with ongoing IV fluids.
Oral rehydration therapy (ORT)
- -using commercially prepared oral rehydration solutions (ORS) that contain glucose and electrolytes is used in cases of mild-moderate dehydration.
- -ORT is as effective, safer, and much less costly than intravenous therapy.
- -ORT can be used effectively even when children are still having some vomiting.
recommended volume for mild-moderate dehydration
50-100 mL/kg
Work-Up of Probable Pyloric Stenosis: Pyloric US
In experienced hands, a pyloric ultrasound is the study of choice to confirm pyloric hypertrophy
Work-Up of Probable Pyloric Stenosis: Upper GI contrast study
- demonstrate a very narrow pyloric channel (the “string sign”), indentation of the hypertrophied pylorus on the antrum of the stomach, and delayed gastric emptying.
- If there is significant concern for malrotation or volvulus, the upper GI study should include imaging of contrast passing through the small intestine as well. But the absence of bilious emesis suggests no obstruction beyond the pylorus.
Work-Up of Probable Pyloric Stenosis: Electrolytes
- Pyloric stenosis is typically associated with electrolyte abnormalities because of loss of stomach fluid and inadequate fluid intake. These abnormalities include hypochloremia, hypokalemia, and alkalosis.
- Correction of metabolic status is necessary before corrective surgery can be performed.
Differential Diagnosis for Recurrent Emesis in the Infant: Gastroesophageal reflux (1/8)
- Regurgitation/spitting up may be difficult to distinguish from true vomiting.
- Infants who reflux with overfeeding may sometimes have forceful vomiting.
- Severe esophagitis may result in blood-streaked emesis.
- Pain from reflux or esophagitis may lead to feeding aversion when gastroesophageal reflux is severe.
- An infant who is dehydrated due to severe GE reflux should also have significant failure to thrive.
Differential Diagnosis for Recurrent Emesis in the Infant: Viral gastroenteritis (2/8)
- Early in the course of the infection there may be isolated vomiting, but large watery stools are the hallmark of infectious gastroenteritis.
- Dehydration due to fluid losses often accompanies gastroenteritis.
- Bilious emesis is not typically seen with gastroenteritis or a GI tract obstruction above the ligament of Treitz, but small amounts of bile may be seen with repetitive vomiting.
- “Enteritis” is not truly present if diarrhea is not present.
Differential Diagnosis for Recurrent Emesis in the Infant: Malrotation ± volvulus (3/8)
- Malrotation may be present without volvulus (twisting of the intestine on itself, causing obstruction) and by itself it does not necessarily cause symptoms. However, malrotation may result in volvulus and result in vomiting and other signs of bowel obstruction.
- Bilious emesis is common.
- Blood may be seen in the stool but not typically in the vomitus.
- Bowel ischemia from volvulus can cause significant abdominal pain.
- Infants with malrotation and volvulus may present with shock, which may initially be difficult to distinguish from dehydration.
Differential Diagnosis for Recurrent Emesis in the Infant: Inborn error of metabolism (4/8)
- Although uncommon, metabolic disorders should be considered, particularly in infants with recurrent emesis.
- Symptoms may be triggered by intercurrent illness such as gastroenteritis or infections.
- Infants with inborn errors may present with diminished oral intake for a variety of reasons, including lethargy and irritability.
- Metabolic disorders may also present with shock, which may be difficult to distinguish from severe dehydration.
Differential Diagnosis for Recurrent Emesis in the Infant: Pyloric stenosis (5/8)
- An escalating pattern of forceful (projectile), non-bilious vomiting is a hallmark of pyloric stenosis.
- Bilious emesis is not typical because the obstruction is above the ligament of Treitz.
- Infants with pyloric stenosis can have rapid dehydration due to inadequate fluid absorption, but they typically have a vigorous appetite until late in the clinical course.
- Infants with pyloric stenosis often present with mild-moderate dehydration due to persistent vomiting.
- The presence of hypochloremic, hypokalemic metabolic alkalosis with dehydration is another hallmark of pyloric stenosis.
- Bloody emesis is sometimes seen in pyloric stenosis and other causes of forceful emesis due to the development of Mallory-Weiss tears in the esophagus.
- Infants with pyloric stenosis may demonstrate a visible peristaltic wave (particularly just after eating).
- A palpable “olive” (the hypertrophic pyloric muscle) in the epigastric region very strongly suggests the diagnosis but is not uniformly perceptible.
Differential Diagnosis for Recurrent Emesis in the Infant: Intussusception (6/8)
- Infants with intussusception typically have bilious emesis and crampy or severe abdominal pain.
- The classic “currant jelly” stools of intussusception may be mis-identified in the history as diarrhea.
- The abdominal exam in children with intussusception often shows the presence of a “sausage-like” mass due to the telescoped bowel.
Differential Diagnosis for Recurrent Emesis in the Infant: CNS disease (7/8)
- CNS diseases-such as hydrocephalus, intracranial neoplasm, and trauma (accidental or non-accidental)-must be considered in vomiting children, especially in the absence of fever and diarrhea.
- Milk allergy may present with vomiting immediately after eating but more typically will present with a rash or loose stools; it does not typically cause dehydration.
