Can I administer Lactated Ringer's (LR) solution to a patient with hyperkalemia?

Administering Lactated Ringer's Solution in Hyperkalemia

Normal saline (0.9% NaCl) is preferred over Lactated Ringer's (LR) solution in patients with severe hyperkalemia (potassium >6.0 mEq/L). 1

Understanding Fluid Composition and Hyperkalemia Risk

• Lactated Ringer's solution contains potassium (4 mmol/L), which raises theoretical concerns about worsening hyperkalemia in patients with already elevated potassium levels 1
• Normal saline (0.9% NaCl) contains no potassium and has traditionally been considered safer for patients with hyperkalemia 1
• From a physiological standpoint, it is unlikely that LR would increase potassium levels since the potassium concentration in LR (4 mmol/L) is lower than the patient's current serum level of 6.3 mmol/L 1

Evidence on LR Use in Hyperkalemia

• Recent evidence suggests that LR may not significantly worsen hyperkalemia even in high-risk patients:

  • A retrospective study of patients with reduced kidney function (eGFR <30 ml/min) found that LR use was not independently associated with the development of hyperkalemia 2
  • In renal transplant recipients, LR was actually associated with less hyperkalemia compared to normal saline (0% vs 19% incidence of potassium >6 mEq/L) 3

• However, in disaster medicine guidelines specifically addressing crush injuries with rhabdomyolysis, potassium-containing balanced salt solutions like LR are explicitly contraindicated due to risk of worsening hyperkalemia 1

Clinical Decision Making

• For a patient with a potassium of 6.3 mmol/L (severe hyperkalemia):

  • Normal saline is the safer initial choice for fluid resuscitation to avoid any theoretical risk of worsening hyperkalemia 1
  • The primary concern with normal saline is the risk of hyperchloremic metabolic acidosis with large volume administration, which could potentially worsen hyperkalemia indirectly 3, 4

• For patients requiring large volume resuscitation who have or develop metabolic acidosis:

  • Consider potassium binders (patiromer or sodium zirconium cyclosilicate) if continuing with normal saline 1
  • Once potassium levels decrease below 5.5 mmol/L, transition to balanced crystalloids may be appropriate 1

Special Considerations

• In patients with heart failure and hyperkalemia:

  • Newer potassium binders (patiromer and sodium zirconium cyclosilicate) can help lower potassium levels and enable treatment with renin-angiotensin-aldosterone system inhibitors 1
  • SGLT2 inhibitors may reduce the risk of serious hyperkalemia (hazard ratio 0.84) in patients with type 2 diabetes and high cardiovascular risk or CKD 1

• In patients with continuous kidney replacement therapy:

  • Dialysis solutions containing appropriate potassium, phosphate, and magnesium should be used to prevent electrolyte disorders 1

Conclusion

For a patient with a potassium of 6.3 mmol/L, normal saline is the preferred initial fluid choice over Lactated Ringer's solution to avoid any theoretical risk of worsening hyperkalemia, despite emerging evidence suggesting LR may be safe in many hyperkalemic patients.