Plasma-Lyte A (pH 7.4)

• Core dose: Resuscitation: 500–1000 mL IV bolus as needed; Maintenance: 1–2 mL/kg/hr; Large volume resuscitation preferred over NS
• Onset/duration: Volume effect immediate; similar intravascular persistence to NS (~25% at 1 hr); most redistributes to interstitium
• Key danger: Volume overload in heart/renal failure; mild hyperkalemia risk (contains K⁺ 5 mEq/L); avoid in hyperkalemia
• Special: Balanced crystalloid with acetate/gluconate buffers; near-physiologic pH; less hyperchloremic acidosis vs NS; preferred for large-volume resuscitation per SMART/SALT-ED trials

• Generic/Official: Plasma-Lyte A Injection, pH 7.4 (Multiple Electrolytes Injection, Type 1, USP)
• Brand Names: Plasma-Lyte A

Balanced isotonic crystalloid (acetate/gluconate buffered)

Mechanism of Action (Pharmacodynamics):

• Expands extracellular fluid (intravascular + interstitial)
• Compared with 0.9% saline, lower chloride load and buffer anions reduce risk of hyperchloremic metabolic acidosis and help maintain acid–base neutrality

Disposition (Pharmacokinetics/Physiology):

• Distribution: Rapid distribution from plasma to interstitium; ~25–30% of a bolus persists intravascularly after equilibration
• Metabolism: Acetate/gluconate are quickly metabolized (liver, muscle, kidney) to bicarbonate and CO₂/H₂O
• Elimination: Electrolytes are renally excreted under hormonal control

Adults (Sepsis/Shock):

• Initial crystalloid: 30 mL/kg within 3 hours (guideline suggestion)
• Reassess after each bolus and titrate to perfusion endpoints (MAP ≥65 mmHg, mental status, UOP)
• General bolus examples: 500–1,000 mL with frequent reassessment
• Maintenance rates per institutional protocol and clinical status

Pediatrics:

• Shock/Dehydration bolus: 10–20 mL/kg over 5–20 minutes
• Repeat to 40–60 mL/kg in first hour for septic shock with ICU capability
• Special populations: Adjust aliquots in neonates/cardiac disease

Contraindications:

• Hyperkalemia or risk of hyperkalemia — contains 5 mEq/L K⁺
• Hypermagnesemia or severe renal impairment — contains 3 mEq/L Mg²⁺; avoid if predisposed
• Metabolic alkalosis or hypocalcemia — alkalinizing effect can lower ionized Ca²⁺; contains no calcium

Cautions:

• Fluid overload states (HF, cirrhosis, renal failure)
• Conditions with non-osmotic vasopressin release (SIADH) — risk of hyponatremia/edema with large volumes

Common:

• Fluid overload (peripheral/pulmonary edema)
• Electrolyte shifts (K⁺/Mg²⁺)

Less Common:

• Hypernatremia (less common than with normal saline)
• Metabolic alkalosis with excessive volumes

Local Reactions:

• Phlebitis
• Infiltration

Lithium:

• Sodium-containing solutions may increase renal clearance — monitor levels if co-administered

Drugs that Increase Vasopressin Effect:

• Some antidepressants/antiepileptics: higher hyponatremia risk with large-volume infusions — monitor sodium

Blood Products:

• Institutional policies vary; many centers prefer 0.9% saline for co-infusion/line priming
• Check local policy before Y-site with PRBCs

Perfusion:

• MAP, heart rate, mental status, capillary refill
• Urine output (≥0.5 mL/kg/h adults; ≥1 mL/kg/h children)

Electrolytes/Acid-Base:

• Na⁺, K⁺, Mg²⁺, Cl⁻
• Bicarbonate/base excess; lactate
• ABG/VBG if needed

Renal Function:

• SCr/BUN
• Monitor MAKE30 endpoints in ICU populations during large-volume resuscitation

Cumulative Balance:

• Signs of overload (weights, edema, oxygenation, exam)

Properties:

• Near-physiologic osmolality
• Buffer anions (acetate, gluconate) are metabolized to bicarbonate, producing an alkalinizing effect
• Strong ion difference (SID) ≈ 50 mEq/L

• Initial resuscitation of hypovolemia, sepsis, peri-operative and trauma fluid therapy when a balanced crystalloid is preferred
• Medication carrier and maintenance fluid (institution-specific)
• Acid–base sensitive scenarios to limit hyperchloremic acidosis (e.g., large-volume resuscitation)

• Baxter Healthcare Corporation. (2024). PLASMA-LYTE A Injection pH 7.4 (Multiple Electrolytes Injection, Type 1, USP) — Prescribing Information. DailyMed.
• DailyMed. (2024). PLASMA-LYTE A Injection pH 7.4 — Drug Label.
• Semler, M. W., Self, W. H., Wanderer, J. P., et al. (2018). Balanced crystalloids versus saline in critically ill adults (SMART). New England Journal of Medicine, 378, 829–839.
• Self, W. H., Semler, M. W., Wanderer, J. P., et al. (2018). Balanced crystalloids versus saline in noncritically ill adults (SALT-ED). New England Journal of Medicine, 378, 819–828.
• Evans, L., Rhodes, A., Alhazzani, W., et al. (2021). Surviving Sepsis Campaign: International guidelines for management of sepsis and septic shock 2021. Intensive Care Medicine, 47, 1181–1247.