What should be the initial assessment for a 4-year-old patient weighing 19.5 kg who presented with vomiting?

Initial Assessment of a 4-Year-Old with Vomiting

Immediately assess for dehydration severity and red flag signs, then begin oral rehydration therapy with small, frequent volumes of ORS (5-10 mL every 1-2 minutes) while evaluating for life-threatening causes. 1

Critical Red Flag Signs to Assess Immediately

Evaluate for the following alarm features that indicate serious pathology requiring urgent intervention: 2, 3

• Bilious (green) or bloody vomitus – suggests intestinal obstruction or surgical emergency 2, 3
• Altered mental status or lethargy – may indicate increased intracranial pressure, metabolic derangement, or sepsis 2
• Toxic/septic appearance – suggests systemic infection requiring immediate treatment 2
• Severe or inconsolable abdominal pain – consider appendicitis, intussusception, or other surgical abdomen 2, 3
• Signs of increased intracranial pressure – papilledema, severe headache, focal neurologic deficits 3
• Severe dehydration or shock – requires immediate IV fluid resuscitation 1, 2

Hydration Status Assessment

Assess dehydration severity using clinical signs, as this determines your treatment approach: 1, 4

Mild Dehydration (3-5% deficit):

• Slightly dry mucous membranes
• Normal skin turgor
• Alert and interactive 1

Moderate Dehydration (6-9% deficit):

• Dry mucous membranes
• Decreased skin turgor with prolonged retraction time
• Decreased urine output
• Sunken eyes
• Rapid, deep breathing 4

Severe Dehydration (≥10% deficit):

• Very dry mucous membranes
• Tenting skin turgor
• Minimal or no urine output
• Altered mental status
• Weak or absent pulses
• Hypotension 1, 5

Pertinent History Elements

Obtain focused history to narrow differential diagnosis: 2, 3

• Timing and pattern: Acute (hours to days) vs. chronic (>4 weeks), relationship to meals 3, 6
• Character of vomitus: Bilious, bloody, undigested food, projectile 2, 3
• Associated symptoms: Fever (suggests infection), diarrhea (gastroenteritis), headache (migraine, increased ICP), abdominal pain location and severity 2, 3
• Recent exposures: Sick contacts, travel, new foods, medications, toxin ingestion 2, 6
• Urine output: Last void time, frequency, color 1, 4
• Oral intake tolerance: Ability to keep down any fluids 1

Physical Examination Priorities

Conduct a systematic examination focusing on: 3

• Vital signs: Blood pressure (hypotension suggests severe dehydration or shock), heart rate, respiratory rate and pattern 3, 2
• Abdominal examination: Distension, tenderness, guarding, rebound, bowel sounds, masses, check hernial orifices and genitalia 3
• Neurologic examination: Mental status, fundoscopy for papilledema, focal deficits 3
• Weight: Compare to recent documented weights if available 1, 4

Immediate Management Based on Assessment

If Red Flags Present:

• Stop all oral intake immediately 2
• Place nasogastric tube for gastric decompression if bilious vomiting present 2
• Obtain urgent surgical consultation for suspected obstruction 3
• Initiate IV isotonic fluids (lactated Ringer's or normal saline) if severe dehydration or shock 1, 5
• Order appropriate imaging: Abdominal X-ray for suspected obstruction, head CT for suspected increased ICP 2, 3

If No Red Flags and Mild-Moderate Dehydration:

Begin oral rehydration therapy immediately: 1, 4

• For moderate dehydration (6-9%): Give 100 mL/kg ORS over 2-4 hours (approximately 1,950 mL for this 19.5 kg child) 1, 4
• For mild dehydration (3-5%): Give 50 mL/kg ORS over 2-4 hours (approximately 975 mL) 1
• Technique: Administer 5-10 mL every 1-2 minutes using teaspoon, syringe, or medicine dropper – never allow rapid drinking from cup or bottle as this perpetuates vomiting 1, 5
• Replace ongoing losses: Give 10 mL/kg (195 mL) for each additional diarrheal stool and 2 mL/kg (39 mL) for each vomiting episode 1, 4

Consider Ondansetron as Adjunct:

If vomiting prevents adequate oral intake, administer ondansetron 0.2 mg/kg orally (maximum 4 mg) to improve ORS tolerance and reduce need for IV therapy 1, 2

When to Escalate Care

Switch to IV therapy if: 1, 5

• Progression to severe dehydration or shock
• Altered mental status develops
• ORS therapy fails despite proper technique
• Stool output exceeds 10 mL/kg/hour
• Intractable vomiting despite ondansetron 1, 5

Reassessment Timeline

Reassess hydration status after 2-4 hours by examining: 1, 4

• Skin turgor and mucous membrane moisture
• Mental status and activity level
• Urine output (should void within 6-8 hours if adequately rehydrated)
• Weight changes
• Vital signs 1, 4

If still dehydrated after initial rehydration period, reestimate fluid deficit and restart therapy 4

Common Pitfalls to Avoid

• Do not delay rehydration while awaiting diagnostic tests in a stable child without red flags 5
• Do not give antimotility agents (loperamide) – these are contraindicated in all children <18 years 1, 5
• Do not prescribe empiric antibiotics for uncomplicated vomiting with watery diarrhea – this is typically viral gastroenteritis requiring only supportive care 5
• Do not restrict diet – resume age-appropriate feeding immediately after rehydration is complete (within 4 hours) 1, 5