Chart — IV Therapy

IV Solution Comparison

Normal Saline, Lactated Ringer's, D5W, Half Normal Saline, D5½NS, 3% NaCl, and D10W compared by classification, osmolarity, mechanism, clinical uses, and key nursing considerations.

Educational use only. 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.

Classification Quick Reference

Solution	Classification	Osmolarity	Water Movement	Volume Resuscitation?
0.9% NaCl (NS)	Isotonic	308 mOsm/L	No net shift	Yes — 1st choice
LR	Isotonic	273 mOsm/L	No net shift	Yes (no blood products)
D5W	Isotonic → Hypotonic	252 mOsm/L	INTO cells (after metabolism)	No
0.45% NaCl (½NS)	Hypotonic	154 mOsm/L	INTO cells	No
D5½NS	Hypertonic → Hypotonic	406 mOsm/L	INTO cells (after metabolism)	No
3% NaCl	Hypertonic	1026 mOsm/L	OUT of cells	No (cerebral edema use)
D10W	Hypertonic	505 mOsm/L	OUT of cells	No

Normal serum osmolarity: 275–295 mOsm/L

Solution Detail Cards

Normal Saline

0.9% NaCl (NS)

Isotonic

Osmolarity: 308 mOsm/L

Electrolytes: Na⁺ 154, Cl⁻ 154 mEq/L

Mechanism: No net osmotic shift — stays in extracellular space

Common Uses

Volume replacement (1st choice)
Blood transfusion compatible flush
Medication dilution
Na⁺ replacement
Pre/post-procedure hydration

Key Considerations

⚠ Large volumes → hyperchloremic metabolic acidosis (high Cl⁻)
Avoid in hypernatremia
May worsen fluid overload in CHF/CKD/cirrhosis

NCLEX: Most common crystalloid in acute care — first-line for resuscitation

Lactated Ringer's

Isotonic

Osmolarity: 273 mOsm/L

Electrolytes: Na⁺ 130, K⁺ 4, Ca²⁺ 3, Cl⁻ 109, Lactate 28 mEq/L

Mechanism: Stays in extracellular space; lactate metabolized to bicarbonate in liver

Common Uses

Volume replacement
Burns (Parkland formula)
Trauma/surgical resuscitation
Mild acidosis

Key Considerations

🚫 INCOMPATIBLE with blood — calcium causes clotting
🚫 Avoid in severe liver failure (cannot metabolize lactate)
🚫 Avoid in hyperkalemia (contains 4 mEq/L K⁺)

NCLEX: Do NOT use with blood transfusions — calcium in LR clots blood

D5W

5% Dextrose in Water

Isotonic in bag → Hypotonic after metabolism

Osmolarity: 252 mOsm/L (functionally hypotonic after glucose metabolism)

Electrolytes: None (dextrose only)

Mechanism: After glucose metabolized → free water distributed equally intra/extracellularly

Common Uses

Medication delivery / dilution
Free water supplement in hypernatremia
Mild hypoglycemia
Caloric supplementation (170 kcal/L)

Key Considerations

🚫 NEVER for volume resuscitation — does not expand vascular space after metabolism
🚫 Avoid in head injury or cerebral edema
⚠ Monitor blood glucose — raises BG
⚠ Large volumes → hyponatremia

NCLEX: D5W = free water after glucose metabolism. Never use for shock or volume replacement.

Half Normal Saline

0.45% NaCl (½NS)

Hypotonic

Osmolarity: 154 mOsm/L

Electrolytes: Na⁺ 77, Cl⁻ 77 mEq/L

Mechanism: Water moves from vascular space INTO cells — rehydrates intracellular compartment

Common Uses

Cellular dehydration (DKA after initial isotonic phase)
Hypernatremia — gentle correction
Maintenance hydration in some patients

Key Considerations

🚫 Contraindicated in head injury, SIADH, existing hyponatremia
🚫 Never for fluid resuscitation — does not expand intravascular volume
⚠ Risk of cerebral edema if infused too rapidly

NCLEX: Hypotonic = water moves INTO cells. Avoid in neuro/cerebral edema patients.

D5½NS

5% Dextrose in 0.45% NaCl

Hypertonic in bag → Hypotonic after glucose metabolism

Osmolarity: 406 mOsm/L (in bag)

Electrolytes: Na⁺ 77, Cl⁻ 77 mEq/L + 5% dextrose

Mechanism: Hypertonic until glucose metabolized → behaves as ½NS (hypotonic)

Common Uses

Maintenance IV fluids (common inpatient maintenance)
Provides hydration + glucose supplementation
Post-operative maintenance (often + KCl 20 mEq/L)

Key Considerations

⚠ Monitor blood glucose
⚠ Not for volume resuscitation
⚠ After glucose metabolism: hypotonic effects — monitor Na⁺ with prolonged use

NCLEX: Most common maintenance IV fluid in hospitalized patients

3% NaCl

Hypertonic Saline

Hypertonic

Osmolarity: 1026 mOsm/L

Electrolytes: Na⁺ 513, Cl⁻ 513 mEq/L

Mechanism: Pulls water OUT of cells into vascular space — rapidly raises serum Na⁺; reduces cerebral edema

Common Uses

Symptomatic severe hyponatremia (seizures, coma, respiratory distress)
Cerebral edema / elevated ICP
SIADH refractory to restriction

Key Considerations

🚫 MUST use central line — severe phlebitis if peripheral infusion
🚫 Never bolus — controlled pump infusion only
⚠ Correct Na⁺ no faster than 8–12 mEq/L in 24 hrs — risk of osmotic demyelination syndrome (ODS)
⚠ Monitor serum Na⁺ every 2–4 hours during infusion

NCLEX: Hypertonic saline = central access required. Rapid Na⁺ correction → osmotic demyelination syndrome (ODS).

D10W

10% Dextrose in Water

Hypertonic

Osmolarity: 505 mOsm/L

Electrolytes: None (dextrose only)

Mechanism: Pulls water from extravascular space; provides concentrated caloric source

Common Uses

Neonatal hypoglycemia
Interim glucose support (TPN bridge)
Prevention of rebound hypoglycemia after insulin infusion

Key Considerations

⚠ Central access preferred for prolonged infusion
⚠ Monitor BG closely — 10× dextrose concentration vs D5W
Not for general resuscitation

NCLEX: D10W is hypertonic — used in neonatal settings and hypoglycemia rescue; monitor BG.

Critical Safety Rules

Situation	Risk / Rule
LR + blood	Calcium in LR binds citrate anticoagulant → clot formation. Only NS is compatible with blood products.
D5W for shock	After glucose metabolism, D5W = free water. Does NOT expand intravascular volume. Never use for resuscitation.
3% NaCl peripheral infusion	Causes severe phlebitis/tissue necrosis. Central venous access is REQUIRED.
Rapid Na⁺ correction	Na⁺ must not rise faster than 8–12 mEq/L in 24 hours. Risk: osmotic demyelination syndrome (central pontine myelinolysis).
½NS in head injury	Hypotonic fluid moves water INTO brain cells → worsens cerebral edema.
LR in liver failure	Liver cannot metabolize lactate → accumulation → worsens metabolic acidosis.

Related Resources

IV Solution Types ReferenceFull detail for each solution — mechanism, indications, cautions, and NCLEX pearls

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IV Therapy Fundamentals GuideFluid compartments, classification, maintenance vs replacement, nursing monitoring

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Electrolyte Imbalance RecognitionHow fluid choices affect Na⁺, K⁺, and other electrolytes

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IV Therapy ComplicationsFluid overload and other complications from IV fluid administration

Open →

Data source: Intravenous Nurses Society (INS) Standards of Practice / Evidence-Based IV Fluid Therapy Guidelines

Standards & sources

Fact-checked Jun 21, 2026

This page is written to align with INS Standards of Practice for Infusion Nursing / Evidence-Based IV Fluid Therapy Guidelines. 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 →