From the Guidelines
Projectile vomiting in a 5-week-old infant is most commonly caused by pyloric stenosis, a condition where the muscle controlling the outlet from the stomach (pylorus) becomes abnormally thickened, preventing food from passing into the small intestine. Other potential causes include gastroesophageal reflux disease (GERD), formula intolerance, overfeeding, improper feeding technique, gastroenteritis, or rarely, metabolic disorders or increased intracranial pressure. Pyloric stenosis typically presents between 2-8 weeks of age with progressively worsening forceful vomiting that arcs several feet, often after feeds, as noted in the study by 1. The infant may be hungry immediately after vomiting and show signs of dehydration or failure to thrive. This condition requires prompt medical attention as it typically necessitates surgical correction through a procedure called pyloromyotomy. Parents should seek immediate medical care if their infant exhibits projectile vomiting, especially if accompanied by weight loss, lethargy, decreased wet diapers, or inconsolable crying, as these may indicate serious conditions requiring urgent intervention, as suggested by 1 and 1. Early diagnosis is crucial to prevent complications like dehydration, electrolyte imbalances, and malnutrition. Some key points to consider in the diagnosis and management of projectile vomiting in infants include:
- Differentiating between gastroesophageal reflux (GER) and gastroesophageal reflux disease (GERD), as noted in the study by 1
- Considering other potential causes of vomiting, such as formula intolerance, overfeeding, or improper feeding technique, as mentioned in the study by 1
- Evaluating the infant for signs of dehydration, failure to thrive, or other complications, as recommended by 1
- Seeking immediate medical attention if the infant exhibits projectile vomiting, especially if accompanied by other concerning symptoms, as emphasized by 1 and 1.
From the Research
Causes of Projectile Vomiting in Infants
The causes of projectile vomiting in a 5-week-old infant can be attributed to several factors, including:
- Pyloric stenosis (PS): a condition where the pylorus, the passage between the stomach and small intestine, becomes narrowed, causing vomiting 2
- Gastroesophageal reflux (GER): a condition where stomach acid flows back into the esophagus, causing vomiting 2, 3
- Other gastrointestinal issues: such as hypertrophic pyloric stenosis, intussusception, and small bowel obstruction 4
Diagnostic Approaches
To differentiate between PS and GER, diagnostic criteria such as serum bicarbonate and serum chloride levels can be used 2.
- Serum bicarbonate levels of > or =29 mmol/L and serum chloride levels of < or =98 mmol/L have high positive predictive values and are specific for PS 2
- Point-of-care ultrasound can also be used to diagnose gastrointestinal and biliary pathologies, including hypertrophic pyloric stenosis 4