Intravenous fluids

Intravenous fluids

Drug monograph · NCLEX study reference
Therapeutic class	IV fluid and electrolyte replacement
Pharmacologic class	Crystalloid solutions by tonicity
Onset / peak / duration	Immediate during infusion.
Half-life / level	Not applicable; guided by clinical status and labs.
Routes	IV
High-alert (ISMP)	No
Black box warning	None
Antidote / reversal	Adjust the fluid plan; diuretics for overload.
Pregnancy / lactation	Used as needed.

Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.

Intravenous fluids — IV fluid and electrolyte replacement; Crystalloid solutions by tonicity.

Identification

• Therapeutic class: IV fluid and electrolyte replacement.
• Pharmacologic class: Crystalloid solutions by tonicity.

Pharmacology

• Mechanism of action: Isotonic fluids stay in the vascular space to expand volume; hypotonic fluids shift water into cells; hypertonic fluids pull water out of cells into the vascular space.
• Onset / peak / duration: Immediate during infusion.
• Half-life / therapeutic level: Not applicable; guided by clinical status and labs.

Clinical use

• Indications: Isotonic for volume resuscitation and maintenance (normal saline, lactated Ringer's); hypotonic for cellular dehydration (0.45% saline); hypertonic for severe hyponatremia or cerebral edema (3% saline) and caloric needs.
• Usual dose, route, frequency: IV at a rate set by the clinical need.
• Maximum dose / adjustments: Adjust for cardiac, renal, and hepatic status; hypertonic saline through monitored access and slow correction.

Safety

• Contraindications: Lactated Ringer's caution in liver failure and hyperkalemia; hypertonic saline requires careful sodium correction.
• Black box warning: None.
• Interactions: Lactated Ringer's contains potassium and calcium (incompatible with some drugs, including ceftriaxone in neonates and blood products).
• Pregnancy / lactation: Used as needed.
• High-alert: No.

Adverse effects

• Common side effects: Local infusion effects.
• Serious effects to report: Fluid overload (crackles, edema, dyspnea), rapid sodium shifts (osmotic demyelination with too-fast correction), cellular swelling (overuse of hypotonic), phlebitis.
• Antidote / reversal: Adjust the fluid plan; diuretics for overload.

Nursing process

• Assessment before administration: Volume status, electrolytes, lung and heart sounds, weight, the correct fluid order.
• Interventions during therapy: Verify the right fluid and rate; monitor for overload; correct sodium slowly; hypertonic saline through a monitored line.
• Monitor: Intake and output, weight, lung sounds, electrolytes (especially sodium), vital signs.
• Evaluation / expected outcome: Restored fluid and electrolyte balance.

Patient teaching

• Patient teaching: Report shortness of breath or swelling.
• Notify provider if: Difficulty breathing, swelling, IV-site pain.
• Administration tips: Verify tonicity and rate; D5W becomes hypotonic in the body; hypertonic saline corrected slowly.