IV Fluid Management for Diarrhea
Oral rehydration solution (ORS) is superior to intravenous fluids for treating diarrhea in patients who can tolerate oral intake—it is safer, less costly, less painful, and equally or more effective than IV therapy. 1
When to Use Oral Rehydration vs IV Fluids
Oral Rehydration Solution (First-Line)
- ORS should be used for the vast majority of diarrhea cases in patients capable of oral intake 1
- ORS is not only lifesaving in severe diarrhea but provides superior outcomes compared to IV fluids when oral intake is possible 1
- The patient's thirst naturally decreases during rehydration, providing built-in protection against overhydration 1
- Stool output can be further reduced when ORS is combined with food-based therapy 1
Specific ORS Formulation
Use WHO-recommended concentrations (approximately Na 90 mM, K 20 mM, Cl 80 mM, HCO3 30 mM, glucose 111 mM): 1
- Commercial options: Ceralyte, Pedialyte, or generic solutions 1
- Pharmacy preparation: Mix 3.5 g NaCl, 2.5 g NaHCO3, 1.5 g KCl, and 20 g glucose (or 40 g sucrose or 50-60 g cooked cereal flour) per liter of clean water 1
When IV Fluids Are Indicated
Switch to IV fluids only when: 1
- Patient cannot tolerate oral intake due to severe vomiting
- Signs of severe dehydration are present: dry mucous membranes, decreased skin turgor, absent jugular venous pulsations, orthostatic hypotension, tachycardia, decreased urination, lethargy, or altered sensorium 1
- Patient is obtunded or has altered mental status preventing safe oral intake 1
Clinical Assessment for Dehydration Severity
Evaluate these specific parameters to determine hydration status: 1
- Volume depletion symptoms: thirst, tachycardia, orthostasis, decreased urination, lethargy, decreased skin turgor 1
- Stool characteristics: frequency, quantity, presence of blood, mucus, or pus 1
- Associated symptoms: fever, abdominal pain, nausea, vomiting, headache, myalgias 1
- Duration: diarrhea lasting >1 day, especially with fever, bloody stools, or systemic illness warrants fecal evaluation 1
Adjunctive Nutritional Support
Consider these supplements for patients with documented or likely deficiency: 1
- Vitamin A repletion 1
- Zinc supplementation 1
- Glutamine or its derivatives to aid mucosal injury repair 1
Common Pitfalls to Avoid
- Do not default to IV fluids when patients can safely take oral fluids—this increases cost, pain, and complication risk without improving outcomes 1
- Do not use plain water or sports drinks alone—they lack the proper electrolyte and glucose concentrations needed for optimal intestinal absorption 1
- Avoid antimotility agents (loperamide, opioids) in patients with bloody diarrhea, high fever, or suspected inflammatory/infectious causes until pathogen is identified 1