What is the management approach for a patient presenting with fever, loose bowel movements (LBM), and vomiting?

Management of Fever, Diarrhea, and Vomiting

The primary management approach is oral rehydration therapy with reduced osmolarity oral rehydration solution (ORS) as first-line treatment for mild to moderate dehydration, combined with assessment for infectious causes requiring specific treatment, and symptomatic management with antiemetics and antidiarrheals when appropriate. 1

Initial Assessment

Hydration Status Evaluation

• Assess for specific dehydration signs: decreased skin turgor, dry mucous membranes, sunken eyes, altered mental status, tachycardia, orthostatic hypotension, and decreased urine output 1, 2
• Categorize dehydration severity:
  • Mild: <4% body weight loss 1
  • Moderate: 4-6% body weight loss 1
  • Severe: >6% body weight loss 1
• Document stool frequency, consistency, presence of blood, vomiting frequency, and fever 3

Infectious Workup

• Consider GI pathogen testing including Clostridium difficile particularly in patients with leukocytosis or recent antibiotic use 3
• Stool culture should be obtained if diarrhea is severe, bloody, or persistent 2
• In the current era, acute nausea, vomiting, or diarrhea may represent COVID-19 infection and should be considered until proven otherwise 3

Rehydration Strategy

Mild to Moderate Dehydration

• Provide oral rehydration solution (ORS) as first-line therapy: 50-100 mL/kg over 3-4 hours for children, and 2-4 L for adults 1
• Use commercially available low-osmolarity ORS (e.g., Pedialyte, CeraLyte) 1
• Avoid apple juice, sports drinks like Gatorade, and commercial soft drinks as primary rehydration solutions due to inappropriate electrolyte and sugar content 1
• For ongoing losses: children <2 years receive 50-100 mL after each stool; older children 100-200 mL after each stool; adults as much as desired 3

Severe Dehydration

• Intravenous fluids are indicated for: severe dehydration, shock, altered mental status, or failure of oral rehydration therapy 2
• Use isotonic solutions such as lactated Ringer's or normal saline 2
• Monitor vital signs and track response to rehydration closely 2

Symptomatic Management

Antiemetic Therapy

• Ondansetron can increase success rate of oral rehydration therapy and minimize need for IV therapy and hospitalization 4, 5
• Monitor QTc interval carefully as many antiemetics prolong QT, particularly when combined with other QT-prolonging agents 3

Antidiarrheal Therapy

• Loperamide dosing: 4 mg initially, then 2 mg after every unformed stool or every 4 hours (maximum 16 mg/day) 3
• Some clinicians prefer delaying loperamide initially to avoid obscuring worsening diarrhea that may require more aggressive treatment 3
• Avoid loperamide if bloody diarrhea is present as this may indicate invasive bacterial infection 3

Antimicrobial Therapy

General Principles

• Empiric antimicrobial therapy is generally NOT recommended in immunocompetent children and adults with infectious gastroenteritis 1
• Exceptions requiring empiric antibiotics include:
  • Infants <3 months with suspected bacterial etiology 1
  • Fever, abdominal pain, bloody diarrhea suggesting bacillary dysentery (presumptive Shigella) 1
  • Immunocompromised patients with severe illness and bloody diarrhea 1

Antibiotic Selection When Indicated

• Adults: fluoroquinolone (e.g., ciprofloxacin) or azithromycin 1
• Children: third-generation cephalosporin or azithromycin 1
• Critical caveat: Avoid antimicrobial therapy for STEC O157 and other Shiga toxin-producing E. coli as antibiotics may increase risk of hemolytic uremic syndrome 1

Nutritional Management

• Continue breastfeeding throughout the diarrheal episode in infants 1, 3
• Resume age-appropriate diet during or immediately after rehydration 1
• Avoid prolonged fasting as this does not improve outcomes and may worsen nutritional status 1
• Avoid foods high in simple sugars (soft drinks, undiluted apple juice, presweetened cereals) which exacerbate diarrhea through osmotic effects 1

Complicated Cases Requiring Hospitalization

Hospitalize patients with:

• Sepsis, neutropenia, bleeding, or severe dehydration 3
• Moderate to severe cramping, diminished performance status, or signs of fluid depletion 3
• Failure to respond to oral rehydration plus antiemetic therapy 5

Intensive management includes:

• IV fluids and electrolyte monitoring 3
• Octreotide at 100-150 mcg subcutaneously three times daily or IV (25-50 mcg/h) if severely dehydrated, with dose escalation up to 500 mcg subcutaneously three times daily 3
• Broad-spectrum antibiotics (e.g., fluoroquinolone) 3
• Complete blood count, electrolyte profile, and comprehensive stool workup 3

Prevention Measures

• Practice proper hand hygiene after toilet use, diaper changes, before/after food preparation, and after animal handling 1
• Use infection control measures including gloves, gowns, and handwashing with soap and water when caring for patients with diarrhea 1
• Outpatients with suspected infectious gastroenteritis should self-quarantine and minimize household contact exposure 3