What is the management approach for nausea and vomiting associated with infection?

Management of Nausea and Vomiting Associated with Infection

Adequate hydration is the cornerstone of managing nausea and vomiting associated with infection, with antiemetic medications serving as adjunctive therapy only after hydration is addressed. 1

Initial Assessment and Hydration

Hydration Strategy

• First-line therapy: Reduced osmolarity oral rehydration solution (ORS) for mild to moderate dehydration 1
• For patients unable to tolerate oral intake:
  • Nasogastric administration of ORS (if normal mental status) 1
  • Intravenous fluids (isotonic solutions like lactated Ringer's or normal saline) for:
    • Severe dehydration
    • Shock
    • Altered mental status
    • Failure of oral rehydration therapy
    • Ileus 1

Hydration Protocol

1. Continue IV rehydration until pulse, perfusion, and mental status normalize 1
2. Replace remaining deficit using ORS
3. Administer maintenance fluids once rehydrated
4. Replace ongoing losses with ORS until symptoms resolve 1

Antiemetic Therapy

Children

• Ages >4 years: Ondansetron (5-HT3 receptor antagonist) may be given to facilitate oral rehydration 1

  • Dosing: 0.15 mg/kg orally or IV 1
  • Benefits: Reduces vomiting episodes and immediate need for hospitalization/IV rehydration 1
  • Caution: May increase stool volume as side effect 1

• Ages <4 years: Routine use of antiemetics not recommended 1

• Contraindicated: Antimotility drugs (e.g., loperamide) should not be given to children <18 years with acute diarrhea 1

Adults

• First-line options after adequate hydration:

  • Ondansetron: 8 mg orally or IV 1
  • Metoclopramide: 5-20 mg orally or IV 1
  • Prochlorperazine: 5-10 mg orally or IV 1
  • Dimenhydrinate: Beneficial in adults with acute gastroenteritis 1

• For persistent nausea despite as-needed regimen:

  • Switch to around-the-clock dosing for 1 week 1
  • Consider adding agents with different mechanisms of action for synergistic effect 1
  • Consider opioid rotation if nausea persists longer than a week (for patients on opioids) 1

Special Considerations

Infectious Diarrhea with Vomiting

• Important caution: Antimotility agents (e.g., loperamide) should be avoided in:

  • Inflammatory diarrhea
  • Diarrhea with fever
  • Suspected or proven cases where toxic megacolon may result 1
  • Shigellosis and STEC infections (may worsen clinical condition) 1

• Loperamide use in adults:

  • May be given to immunocompetent adults with acute watery diarrhea only 1
  • Reduces stool volume in traveler's diarrhea and most non-cholera watery diarrhea syndromes 1

Infection Prevention

• Hand hygiene is critical after using toilet, changing diapers, before/after food preparation, before eating, and after handling contaminated items 1
• For healthcare settings: Use gloves, gowns, and proper hand hygiene with soap and water or alcohol-based sanitizers 1

Nutrition During Infection

• Continue human milk feeding in infants throughout diarrheal episodes 1
• Resume age-appropriate usual diet during or immediately after rehydration 1
• Early refeeding decreases intestinal permeability caused by infections and reduces illness duration 1

Common Pitfalls to Avoid

1. Neglecting hydration: Antiemetic therapy is not a substitute for proper fluid and electrolyte replacement 1
2. Premature use of antimotility agents: Can worsen outcomes in certain infections 1
3. Overlooking other causes of nausea/vomiting: Always consider non-infectious causes like medication side effects 2
4. Delaying nutrition: Early resumption of appropriate diet improves outcomes 1

By following this structured approach prioritizing hydration first and using appropriate antiemetics as adjunctive therapy, most patients with infection-associated nausea and vomiting can be effectively managed with reduced morbidity and improved quality of life.