0.9% NaCl (Normal Saline) - Perhaps not so normal after all?

Area of Science:

• Medical Science
• Anesthesiology
• Nephrology

Background:

• Normal saline (NS) is a common crystalloid for fluid resuscitation in the US.
• Surgeons and anesthesiologists often prefer buffered solutions like Lactated Ringer's (LR) and Plasma-Lyte A (PL-A).
• Concerns exist regarding NS toxicity compared to balanced crystalloids.

Purpose of the Study:

• To evaluate the safety and efficacy of normal saline versus balanced crystalloids.
• To assess the potential toxicity of NS in various clinical applications, including red cell washing and salvage.
• To compare NS with PL-A and LR for infusion therapy and blood component handling.

Main Methods:

• Review of animal models and clinical studies comparing NS with balanced crystalloids.
• Analysis of in vitro hemolysis data for NS versus PL-A.
• Examination of FDA approvals and clinical recommendations for crystalloid use.

Main Results:

• NS can cause metabolic acidosis, vascular and renal dysfunction, and abdominal pain compared to balanced crystalloids.
• Recent evidence indicates NS causes significantly more in vitro hemolysis than PL-A.
• LR is traditionally avoided for blood salvage due to clotting concerns, though research suggests this is unlikely.

Conclusions:

• Abundant data raise concerns about the safety of NS for infusion therapy, red cell washing, salvage, and apheresis.
• Plasma-Lyte A is FDA-approved for use with blood components and may be a safer alternative, despite higher costs.
• Further studies are needed to assess NS safety across all clinical uses, with a trend towards adopting safer, more physiologic crystalloids.