Lactated Ringers

LR is a balanced crystalloid used for resuscitation and maintenance in shock, sepsis, trauma, and perioperative care. Compared with normal saline (NS), LR has lower chloride and includes lactate as a buffer, reducing risk of hyperchloremic metabolic acidosis.

• Typical composition (U.S., per liter): Na⁺ 130 mEq, K⁺ 4 mEq, Ca²⁺ 2.7 mEq (≈1.5 mmol), Cl⁻ 109 mEq, lactate (as sodium lactate) 28 mEq; osmolarity ~273 mOsm/L; pH ~6.5
• Indications: Initial fluid for many types of hypovolemia (sepsis, trauma, pancreatitis, GI losses), perioperative fluid, burn resuscitation, and as a carrier fluid for many IV medications
• Resuscitation dosing (adult): Typical bolus 20–30 mL/kg (e.g., 1–2 liters) for hypotension/shock, often in 500–1000 mL increments while reassessing; in sepsis, guidelines suggest up to 30 mL/kg crystalloid within the first 3 hours, individualized based on response and comorbidities
• Maintenance dosing (adult, stable patient): ~1–2 mL/kg/h (e.g., ~75–125 mL/h for a 70-kg adult), adjusted for ongoing losses, heart failure, renal function, and enteral intake

• Initial fluid resuscitation for hypovolemic shock from sepsis, trauma, pancreatitis, burns, or GI losses
• Perioperative fluid management in major surgery and anesthesia
• Maintenance crystalloid in hospitalized patients when oral intake is inadequate (paired with electrolyte and glucose management)
• Burn resuscitation (e.g., Parkland formula uses LR as the crystalloid of choice)
• Carrier fluid for various IV medications (institution-specific compatibility)

Contraindications (relative in most ED/ICU scenarios):

• Known hypersensitivity to any component (rare)
• Severe hyperkalemia (K⁺ 4 mEq/L in LR can contribute to further K⁺ load)
• Situations where calcium-containing solutions are contraindicated (e.g., certain medication infusions or when strict calcium-free solutions are required)

Major Precautions:

• Advanced renal failure or oliguric/anuric states: Risk of volume overload and accumulation of potassium; use cautiously, often favoring smaller boluses and close monitoring
• Severe liver failure: Lactate metabolism may be impaired; LR usually remains acceptable, but clinicians may choose other balanced solutions or monitor lactate trends carefully
• Metabolic alkalosis: LR's alkalinizing effect may aggravate alkalemia in some patients
• Hypercalcemia or calcium-related interactions: LR contains calcium; avoid mixing with medications incompatible with calcium (e.g., some phosphates, certain blood products per institutional policies)
• Traumatic brain injury with elevated ICP: Some protocols favor normal saline or hypertonic solutions; data are evolving and practice varies

Clinical Monitoring:

• Vital signs (HR, BP, MAP), mental status, and perfusion markers (capillary refill, skin temperature)
• Urine output (goal often ≥0.5 mL/kg/h in most adults, ≥1 mL/kg/h in burns or rhabdomyolysis)
• Lung exam, chest imaging, and daily weights when ongoing IV fluids are used to assess for volume overload
• Invasive hemodynamics (e.g., arterial line, central venous pressure, or advanced monitoring) in complex shock states requiring large-volume resuscitation

Laboratory Monitoring:

• Serum electrolytes (Na⁺, K⁺, Cl⁻, HCO₃⁻), lactate, and acid–base status, especially during large-volume resuscitation

• Generic Name: Lactated Ringer's solution (Ringer's lactate)
• Other Names: Lactated Ringer's, Ringer's Lactate, Hartmann's solution (composition varies slightly by region)

Balanced isotonic crystalloid solution; volume expander; alkalinizing solution

• Balanced crystalloid: Approximates plasma electrolyte composition more closely than 0.9% sodium chloride: lower chloride and added buffer (lactate)
• Lactate metabolism: Lactate (as sodium lactate) is metabolized primarily in the liver via gluconeogenic pathways, consuming hydrogen ions and generating bicarbonate, which can help mitigate metabolic acidosis from hypovolemia and saline resuscitation
• Reduced hyperchloremia: Lower chloride content compared with normal saline reduces the risk of hyperchloremic metabolic acidosis and associated renal vasoconstriction
• Distribution: As an isotonic crystalloid, LR distributes rapidly across the extracellular space; only about 25–30% of a given bolus remains intravascular after 30–60 minutes in euvolemic patients
• Calcium content: The presence of calcium makes LR closer to physiologic plasma, but may limit compatibility with some medications or citrated solutions depending on institutional policies

Available Forms:

• Bags: commonly 500 mL, 1000 mL (1 L), and sometimes 250 mL polyolefin or PVC bags
• Standard composition in the U.S.: Na⁺ 130 mEq/L, K⁺ 4 mEq/L, Ca²⁺ 2.7 mEq/L, Cl⁻ 109 mEq/L, lactate 28 mEq/L
• Some regional Hartmann's solutions have slightly different electrolyte profiles; always check local product labeling
• Ready-to-use; do not add medications that are incompatible with calcium or specific electrolyte compositions

Standard Adult Dosing:

Common / Expected Issues:

• Peripheral edema and tissue swelling with large-volume resuscitation
• Mild metabolic alkalinization with repeated large volumes, especially if underlying acidosis resolves
• Local IV discomfort or infiltration

Serious (usually related to volume/clinical context):

• Volume overload and pulmonary edema, particularly in heart failure, renal failure, or aggressive resuscitation
• Worsening hyperkalemia in patients with high baseline potassium or impaired renal excretion
• Dilutional coagulopathy and anemia with massive crystalloid resuscitation instead of early blood product use in hemorrhagic shock

• 1. Semler, M. W., & Kellum, J. A. (2019). Balanced crystalloid solutions. American Journal of Respiratory and Critical Care Medicine, 199(8), 952–960. https://doi.org/10.1164/rccm.201809-1677CI
• 2. SMART Investigators and the Pragmatic Critical Care Research Group. (2018). Balanced crystalloids versus saline in critically ill adults. New England Journal of Medicine, 378(9), 829–839. https://doi.org/10.1056/NEJMoa1711584
• 3. Raghunathan, K., Shaw, A., & Nathanson, B. (2014). Association between the choice of IV crystalloid and in-hospital mortality among critically ill adults with sepsis. Anesthesiology, 119(2), 251–269. https://doi.org/10.1097/ALN.0000000000000305
• 4. Lobo, D. N., Awad, S., & Perkins, A. C. (2016). Perioperative fluid management in major surgery. Anesthesiology, 125(6), 1181–1183. https://doi.org/10.1097/ALN.0000000000001382
• 5. EMCrit Project. (2024). Fluid selection in the ICU (IBCC). https://emcrit.org/ibcc/fluid/