Rosen & Barkin's 5-Minute Emergency Medicine Consult (212 page)

See Also (Topic, Algorithm, Electronic Media Element)

Gastroenteritis

CODES

• 008.5 Bacterial enteritis, unspecified
  
• 008.8 Intestinal infection due to other organism, not elsewhere classified
  
• 787.91 Diarrhea
  

BASICS

• One of the most common pediatric complaints; 2nd only to respiratory infections in overall disease frequency for ED visits
  
• Leading cause of illness and death in children worldwide
  
• Acute infectious enteritis (AIE):
  
  • Vomiting and diarrhea
    
  • Children <5 yr in US typically have 2 episodes annually.
    
  • Responsible for ∼10% of all pediatric ED visits and hospital admissions
    
• Acute change in the “normal” bowel pattern that leads to increased number or volume of stools and lasts <7 days; World Health Organization (WHO) defines case as 3 or more loose or watery stools per day.
  
  • Chronic if the diarrhea persists for >2 wk
    

• Acute enteritis:
  
  • Infectious:
    
    • Viruses: 70–80% of cases:
      
      • Rotavirus most common
        
      • Enteric adenovirus
        
      • Norovirus (foodborne outbreaks)
        
    • Bacteria: 10–20%:
      
      • Escherichia coli, Yersinia
        ,
        Clostridium difficile
        
      • Salmonella, Shigella, Campylobacter
        
      • Vibrio
        
      • Aeromonas
        
    • Parasites 5%:
      
      • Cryptosporidiosis (waterborne)
        
      • Giardia lamblia
        
  • Noninfectious:
    
    • Postinfectious
      
    • Food allergies and intolerance:
      
      • Cow’s milk protein
        
      • Soy protein
        
      • Methyl xanthines
        
      • Lactose intolerance
        
    • Chemotherapy/radiation induced
      
    • Drug induced:
      
      • Antibiotics, laxatives, antacids
        
    • Ingestion of heavy metals—copper, zinc
      
    • Ingestion of plants—hyacinth, daffodils, amanita species
      
    • Vitamin deficiency: Niacin, folate
      
    • Vitamin toxicity: Vitamin C
      
  • Associated with other infections
    
    • Otitis media, UTI, pneumonia, meningitis, appendicitis.
      
• Chronic diarrhea:
  
  • Dietary factors: Excessive consumption of sorbitol or fructose from fruit juices
    
  • Enteric infections in immunocompromised
    
  • Malnutrition
    
  • Endocrine: Thyrotoxicosis, pheochromocytoma
    
  • Inflammatory bowel diseases: Crohn's disease, ulcerative colitis
    
  • Malabsorption syndromes (cystic fibrosis, celiac disease)
    
  • Irritable bowel syndrome
    

DIAGNOSIS

• Frequent, loose stools
  
• Signs of dehydration:
  
  • Watery
    
  • Bloody
    
  • Mucoid
    
  • Sometimes abdominal pain, fever, anorexia
    
  • Tenesmus
    
• Signs of dehydration reflect degree of loss of total body water and vary with the degree of dehydration: Mild <5%, moderate 5–10%, severe >15%
  
• Severe dehydration:
  
  • Mental status change: Often depressed with significant dehydration associated with impaired muscle tone
    
  • Mucous membrane: Dry
    
  • Skin turgor: Decreased
    
  • Anterior fontanel: Depressed
    
  • Blood pressure: Decreased
    
  • Pulse: Tachycardia
    
  • Capillary refill: Prolonged (>2 sec)
    
  • Urine output: Decreased
    
  • Eyes: Sunken and absent tears
    
  • Thirst
    

• Onset and duration
  
• Mental status and muscle tone
  
• Fever and associated symptoms (e.g., abdominal pain, emesis)
  
• Stool frequency and character with blood and mucus
  
• Urine output
  
• Feeding
  
• Recent antibiotics
  
• Recent travel
  
• Possible ingestions
  
• Immunodeficiency
  
• Underlying intestinal anomalies (e.g., Hirschsprung disease)
  

• Abnormal capillary refill >2 sec
  
• Absent tears
  
• Dry mucus membranes
  
• 3 best exam signs for determining dehydration in children are an abnormal respiratory pattern, abnormal skin turgor, and prolonged capillary refill time:
  
  • Clinical dehydration scales based on a combination of physical exam findings are better predictors than individual signs.
    

Majority of children with acute diarrhea do not require any lab tests. Consider workup if:

• Temperature >103°F
  
• Systemic illness
  
• Bloody diarrhea
  
• Prolonged course >2 wk
  
• Tenesmus
  
• Dehydration greater than mild, usually requiring parenteral therapy
  
• Diarrhea with blood or mucus suggests an enteroinvasive inflammatory or cytotoxin-mediated process (
  Salmonella,
  invasive
  E. coli
  ).
  

• CBC with differential, blood culture, urine culture, and UA—if any signs of systemic infection
  
• Basic metabolic panel including electrolytes, BUN, creatinine, bicarbonate, for any child treated with IV hydration for severe dehydration or with those patients with abnormal physical signs:
  
  • Recent evidence suggests that serum bicarbonate is particularly helpful in detecting moderate dehydration.
    
  • Stool pH <5.5 or positive stool-reducing substances are positive in lactose intolerance.
    
  • Stool occult blood
    
• Stool microscopy:
  
  • >5 fecal leucocytes per high-power field are suggestive of invasive bacterial infection:
    
    • Shigella
      
    • Salmonella
      
    • Campylobacter
      
    • Yersinia
      
    • Invasive
      E. coli
      
• Stool culture:
  
  • Unnecessary in most cases unless there is a high likelihood of identifying bacterial pathogens (positive guaiac and/or fecal leucocytes) for which the clinical course and period of contagion may be altered by antibiotic therapy
    
• Consider urine culture in febrile children ≤12 mo.
  

Imaging is usually not indicated. Abdominal x-ray or ultrasound may be useful if the clinical suspicion is high for other diagnoses such as intersussception, ileus, appendicitis.

Usually not indicated unless high clinical suspicion for other diagnoses based on history and physical exam

• Postinfectious:
  
  • Follows acute or bacterial or viral gastroenteritis; often associated with malabsorption, especially lactose
    
• C. difficile
  following use of antibiotics.
  
• Milk allergy
  
• Malrotation with midgut volvulus
  
• Inflammatory bowel disease
  
• Intussusception
  
• Malabsorption syndromes
  
• Extra intestinal infections
  
• Medications altering intestinal flora such as antibiotics (e.g., amoxicillin—clavulanate)
  

TREATMENT

• For severely dehydrated children in shock or near shock, IV or intraosseous access with 20 mL/kg 0.9% NS and 1 g/kg dextrose if hypoglycemic
  
• Alternatively, fluids can be subcutaneously administered using recombinant hyaluronidase human injection using strict protocols
  
• Pulse oximetry
  
• Endotracheal intubation may be required for children in shock.