How should I evaluate and manage an 11-year-old with persistent vomiting for one week?

Evaluation and Management of an 11-Year-Old with One Week of Vomiting

Immediate Red-Flag Assessment

In an 11-year-old with one week of persistent vomiting, you must immediately assess for bilious (green) vomiting, bloody vomitus, severe dehydration, altered mental status, and signs of surgical abdomen—any of these findings constitutes a medical emergency requiring urgent intervention. 1

Critical Red Flags Requiring Emergency Evaluation

• Bilious vomiting indicates intestinal obstruction distal to the ampulla of Vater and requires immediate surgical consultation for possible malrotation with volvulus, even though this is less common at age 11 than in infancy 1, 2
• Bloody vomitus or hematemesis suggests mucosal damage from intussusception, peptic ulcer disease, or other serious gastrointestinal pathology requiring urgent assessment 1, 2
• Severe dehydration (≥10% fluid deficit) manifested by prolonged skin tenting >2 seconds, cool extremities, decreased capillary refill, lethargy, and rapid deep breathing mandates immediate intravenous fluid resuscitation 1, 3
• Altered mental status, severe lethargy, or toxic appearance may indicate sepsis, meningitis, increased intracranial pressure, metabolic disorder, or toxic ingestion 1, 4
• Severe localized abdominal pain with peritoneal signs (guarding, rebound tenderness) raises concern for appendicitis, which must be actively excluded in this age group 2, 5

Hydration Status Evaluation

Assess dehydration severity using clinical signs: mild (3-5% deficit) shows slightly dry mucous membranes and increased thirst; moderate (6-9% deficit) demonstrates loss of skin turgor, dry mucous membranes, and reduced urine output; severe (≥10% deficit) presents with lethargy, prolonged skin tenting >2 seconds, cool extremities, and reduced capillary refill. 1, 3

• The most reliable bedside predictors are abnormal capillary refill time, prolonged skin retraction >2 seconds, and rapid deep breathing—these correlate better with true fluid deficit than sunken fontanelle or absent tears 1, 3
• Document recent fluid intake and urine output; fewer than 3-4 urinations in 24 hours suggests significant dehydration 2, 6

Diagnostic Approach Based on Vomitus Characteristics

If Vomiting is Bilious (Green)

• Obtain abdominal radiograph immediately as the first imaging study to identify obstruction patterns 1
• Look for "double-bubble" sign (duodenal obstruction), "triple-bubble" sign (jejunal obstruction), or air-fluid levels suggesting bowel obstruction 1
• Urgent surgical consultation is mandatory; do not delay for extensive workup 1, 4
• Place nasogastric tube for gastric decompression and keep patient NPO 4

If Vomiting is Non-Bilious

• Consider viral gastroenteritis (most common), food poisoning, urinary tract infection, appendicitis (early presentation), metabolic disorders, toxic ingestion, or increased intracranial pressure 1, 4, 5
• Perform focused abdominal examination for distension, tenderness (especially right lower quadrant), masses, and quality of bowel sounds 1, 2
• Serial abdominal examinations are critical to detect development of peritoneal signs that would indicate appendicitis or other surgical pathology 2

Essential History Elements

• Vomitus characteristics: bilious, bloody, projectile, or non-bilious 1
• Stool pattern: bloody, "currant-jelly," watery, absent, or normal 1
• Associated symptoms: fever, abdominal pain location and character, headache, altered mental status 1, 4
• Recent exposures: antibiotics (risk of C. difficile), daycare, foreign travel, sick contacts, new foods 1
• Temporal pattern: relationship to meals, time of day, progression over the week 5
• Neurologic symptoms: headache, vision changes, dizziness suggesting increased intracranial pressure 1, 4

Laboratory Evaluation

Indicated for Moderate-to-Severe Dehydration or Red Flags

• Serum electrolytes and blood gases to assess for metabolic alkalosis (pyloric stenosis, though rare at this age), acidosis, or electrolyte abnormalities 4, 7
• Blood urea nitrogen and creatinine to evaluate renal function and severity of dehydration 7
• Urinalysis with microscopy and urine culture to exclude urinary tract infection or pyelonephritis, which commonly presents with vomiting in children 3
• Blood cultures if febrile or toxic-appearing to rule out sepsis 3

Stool Studies

• Obtain stool cultures when any of the following are present: bloody diarrhea, white blood cells on stool stain, recent antibiotic use, daycare exposure, recent travel, or immunodeficiency 1, 7
• Stool studies are not routinely needed for typical watery diarrhea with vomiting when viral gastroenteritis is the likely diagnosis 6

Management Algorithm

For Mild Dehydration (3-5% Deficit)

• Initiate oral rehydration solution (ORS) at 50 mL/kg over 2-4 hours using small, frequent volumes (5-10 mL every 1-2 minutes via spoon or syringe) 1, 3
• Replace ongoing losses with 10 mL/kg ORS for each watery stool and 2 mL/kg for each vomiting episode 1, 3
• Resume age-appropriate normal diet immediately during or after rehydration; do not withhold food 1, 3
• Avoid sports drinks, apple juice, or soft drinks as primary rehydration fluids due to inappropriate electrolyte composition and excess simple sugars 1, 3

For Moderate Dehydration (6-9% Deficit)

• Administer 100 mL/kg ORS over 2-4 hours using the same small-volume technique 1, 3
• Ondansetron 0.15 mg/kg (single oral dose, maximum 8 mg) may be given to children >4 years with significant vomiting to facilitate oral rehydration 1, 3, 4
• Reassess hydration status after 2-4 hours; if still dehydrated, recalculate deficit and restart rehydration 1, 3
• Success rates exceed 90% when proper small-volume, slow-administration technique is used 1, 3

For Severe Dehydration (≥10% Deficit)

• Immediate hospitalization and IV fluid resuscitation with 20 mL/kg boluses of lactated Ringer's or normal saline, repeated until pulse, perfusion, and mental status normalize 1, 3
• After mental status improves, transition to ORS to replace remaining fluid deficit 1, 3
• Monitor vital signs, capillary refill, skin turgor, mental status, and urine output every 2-4 hours 3

Antimicrobial Therapy

Routine antibiotics are NOT indicated because viral pathogens cause the vast majority of acute gastroenteritis in children 1, 3

Consider Antibiotics Only When:

• Bloody diarrhea with high fever and systemic toxicity suggesting bacterial dysentery (Shigella, Salmonella, Campylobacter) 1, 3
• Watery diarrhea persisting >5 days 3
• Positive stool culture identifies a treatable bacterial pathogen 1, 3
• Immunocompromised host 3

Medications to Avoid

• Loperamide and all antimotility agents are absolutely contraindicated in children <18 years due to risk of severe abdominal distension, ileus, and death 1, 3
• Metoclopramide should not be used for gastroenteritis as it is ineffective and counterproductive 3
• Adsorbents (kaolin-pectin), antisecretory drugs, and toxin binders lack proven efficacy and should be avoided 1, 3

Hospitalization Criteria

Admit patients with any of the following:

• Severe dehydration (≥10% deficit) or clinical shock 1, 3
• Failure of oral rehydration therapy despite proper technique and ondansetron 1, 3
• Altered mental status or severe lethargy 1, 3
• Intractable vomiting despite antiemetic use 3
• Bilious vomiting or signs of intestinal obstruction 1, 4
• Bloody diarrhea with fever and systemic toxicity (monitor for hemolytic-uremic syndrome) 1, 3
• Significant comorbidities or immunocompromised state 3

Nutritional Management

• Resume age-appropriate normal diet immediately during or after rehydration; fasting or food restriction worsens outcomes 1, 3
• Recommended foods include starches (rice, potatoes, noodles), cereals, yogurt, fruits, and vegetables 1, 3
• Avoid foods high in simple sugars (soft drinks, undiluted fruit juice, gelatin), high-fat foods, and caffeinated beverages 1, 3
• Early refeeding reduces intestinal permeability, shortens illness duration, and improves nutritional outcomes 3

Common Pitfalls to Avoid

• Do not delay rehydration while awaiting diagnostic tests; initiate ORT immediately based on clinical assessment 3
• Do not dismiss persistent vomiting as "just gastroenteritis" without excluding appendicitis, especially if abdominal pain is present or develops 2, 5
• Do not use large-volume cup drinking for ORS administration; this triggers vomiting and gives the false impression that oral rehydration has failed 1, 3
• Do not underestimate dehydration severity in children who may not manifest classic signs early in the course 3
• Do not withhold food during or after rehydration; this prolongs illness and impairs recovery 1, 3

Follow-Up Instructions

Instruct parents to return immediately if:

• Vomiting becomes bilious (green) or projectile 2
• Blood appears in vomit or stool 2
• Signs of dehydration develop or worsen (decreased urine output, lethargy, dry mucous membranes) 2
• Abdominal pain worsens or localizes to the right lower quadrant 2
• Child becomes lethargic or develops altered mental status 2
• Fever increases or persists beyond 3-5 days 2