What is the best course of action for a 10-month-old female with acute onset vomiting and no other symptoms?

Management of Acute Vomiting in a 10-Month-Old Female Without Other Symptoms

For a 10-month-old with isolated acute vomiting and no red flag symptoms, immediately assess hydration status and initiate oral rehydration with small, frequent volumes while continuing regular feeds—this is most likely viral gastroenteritis requiring supportive care only. 1, 2, 3

Immediate Assessment Priorities

Hydration Status Evaluation:

• Assess dehydration severity using capillary refill time, which correlates well with fluid deficit 1
• Mild dehydration (3-5% deficit): decreased skin turgor, dry mucous membranes 1
• Moderate dehydration (6-9% deficit): sunken eyes, decreased urine output 1
• Severe dehydration (≥10% deficit): altered mental status, poor perfusion—requires emergency IV therapy 1

Red Flag Symptoms to Rule Out:

• Bilious (green) vomiting suggests intestinal obstruction and requires immediate surgical evaluation 2, 3
• Projectile vomiting may indicate pyloric stenosis (though typically presents 2-8 weeks of age, not 10 months) 2
• Blood in vomit or stool, abdominal distension, or lethargy warrant urgent evaluation 2
• Fewer than 4 wet diapers in 24 hours indicates significant dehydration 2

Management Approach

Hydration Management:

• For mild dehydration: administer 50 mL/kg of oral rehydration solution (ORS) over 2-4 hours 1
• Start with very small volumes (5 mL every minute) using a teaspoon or syringe to prevent triggering more vomiting 2, 3
• Replace each vomiting episode with 10 mL/kg of ORS 1, 2
• Reassess hydration status after 2-4 hours and adjust accordingly 1

Nutritional Management:

• Do not withhold feeds—this is a common pitfall 1, 3
• If breastfed: continue nursing on demand throughout the illness 1, 3
• If formula-fed: continue full-strength formula immediately in amounts sufficient to satisfy energy requirements 1, 3
• Consider lactose-free formula only if diarrhea worsens significantly with lactose-containing formula (true lactose intolerance is uncommon) 1

Antiemetic Considerations:

• Antiemetics are generally NOT indicated for routine viral gastroenteritis in infants this age 2
• Ondansetron (0.2 mg/kg oral, maximum 4 mg) may be considered only if persistent vomiting completely prevents oral intake 2, 4
• The priority is fluid replacement, not medication 1, 2

When to Escalate Care

Return immediately or call if:

• Vomiting becomes bilious (green) or projectile 2, 3
• Signs of worsening dehydration develop (decreased urine output, lethargy, sunken eyes) 2
• Abdominal distension or severe tenderness appears 3
• Blood appears in vomit or stool 2
• The infant becomes lethargic or difficult to arouse 2

Expected Clinical Course

Most likely diagnosis: Viral gastroenteritis, which is self-limiting and resolves within 7 days 1, 5

Follow-up monitoring:

• Regular weight checks are essential—poor weight gain would elevate concern for gastroesophageal reflux disease rather than simple viral illness and warrant specialist referral 2, 3
• The absence of fever, bilious vomiting, and presence of normal stool/gas passage makes mechanical obstruction highly unlikely 2

Common pitfall to avoid: Do not stop breastfeeding or formula feeding in an attempt to "rest the stomach"—this outdated practice delays recovery and worsens dehydration 1, 3