Chart — IV Therapy
Common IV Fluids Chart
IV fluid selection is based on the patient's clinical condition, electrolyte status, and fluid compartment needs. Understanding tonicity, osmolarity, and the behavior of each fluid in the body is a foundational nursing competency.
Educational use only. IV fluid selection and administration rates must be individualized and ordered by a provider. Always assess the patient's fluid status, electrolytes, and clinical response. Data sourced from AANA / clinical practice standards. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Tonicity — The Key Concept
Tonicity describes how a fluid's osmolarity compares to normal plasma (~275–295 mOsm/L). It determines how fluid moves across cell membranes.
Isotonic IV Fluids
| Fluid | Approx. mOsm/L | Indications | Nursing Considerations |
|---|---|---|---|
| Normal Saline (0.9% NaCl) | 308 | Hypovolemia, resuscitation, fluid challenges, blood transfusion diluent, medication administration | Large volumes can cause hyperchloremic metabolic acidosis; monitor for fluid overload in cardiac/renal patients |
| Lactated Ringer's (LR) | 273 | Resuscitation, burns, trauma, surgical fluid replacement | Contains potassium — avoid or use cautiously in renal failure; preferred over NS for large-volume resuscitation in many protocols |
| D5W (5% Dextrose in Water) | 252 (isotonic in bag; becomes hypotonic once dextrose is metabolized) | Free water replacement, medication dilution, hypoglycemia prevention during NPO | Functions as hypotonic after dextrose is metabolized — do not use for volume expansion; raises blood glucose |
| PlasmaLyte A | 294 | Balanced crystalloid for resuscitation, perioperative use | Better electrolyte balance than NS; less risk of hyperchloremic acidosis |
Hypotonic IV Fluids
| Fluid | Approx. mOsm/L | Indications | Nursing Considerations |
|---|---|---|---|
| 0.45% NaCl (Half Normal Saline) | 154 | Cellular hydration in hypernatremia, diabetic ketoacidosis (after initial NS resuscitation) | Can cause cellular swelling — contraindicated in increased ICP, risk of cerebral edema; do not use for volume expansion |
| 0.33% NaCl (1/3 Normal Saline) | 103 | Pediatric maintenance fluids, hyperosmolar states | Very hypotonic — requires careful monitoring; rarely used in adults |
| D5W (after dextrose metabolism) | ~0 (free water) | Free water delivery, medication dilution | Becomes free water once dextrose metabolized — distributes throughout total body water, not just vascular space |
Hypertonic IV Fluids
| Fluid | Approx. mOsm/L | Indications | Nursing Considerations |
|---|---|---|---|
| 3% NaCl (Hypertonic Saline) | 1,026 | Severe symptomatic hyponatremia (seizures, coma), cerebral edema (selected cases) | High-alert medication — requires ICU-level monitoring; correct sodium too rapidly risks osmotic demyelination syndrome (central pontine myelinolysis); administer via central line preferred |
| D10W (10% Dextrose) | 505 | Hypoglycemia treatment, parenteral nutrition component, neonatal glucose maintenance | Monitor blood glucose closely; vesicant properties — use central line for prolonged infusion |
| D5NS (D5W + 0.9% NaCl) | 560 | Maintenance fluids, replace losses with both fluid and glucose needs | Monitor glucose and sodium; not for resuscitation |
| D5 ½ NS (D5W + 0.45% NaCl) | 406 | Common maintenance fluid for adults with both glucose and electrolyte needs | Widely used maintenance fluid; monitor glucose and electrolytes |
NCLEX Key Points
- Isotonic fluids expand intravascular volume — used for hypovolemia, hemorrhage, resuscitation
- Hypotonic fluids hydrate cells — used for cellular dehydration, hypernatremia; never use for volume expansion
- Hypertonic fluids pull fluid from cells into vessels — reserved for severe, symptomatic electrolyte imbalances with close monitoring
- D5W is isotonic in the bag but acts as free water after dextrose is metabolized — do not confuse with NS for resuscitation
- Blood products (PRBCs, FFP, platelets) are always compatible with 0.9% NS only — never dilute with dextrose-containing fluids
- Monitor for fluid overload in all patients receiving IV fluids: lung sounds, weight, edema, urine output, BP
Related References
Standards & sources
Fact-checked Jun 21, 2026This page is written to align with AANA / Clinical Practice Standards. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →