What are the implications of using high-volume normal saline infusion during endoscopic procedures?

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Last updated: September 26, 2026 • View editorial policy

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High-Volume Normal Saline Endoscopic Infusion: Critical Implications

High-volume normal saline infusion during endoscopic procedures carries significant risks of hyperchloremic acidosis, acute kidney injury, and increased mortality—you should use buffered crystalloid solutions instead. 1

Key Metabolic and Renal Complications

The 2024 Perioperative Quality Initiative guidelines provide the strongest evidence against high-volume normal saline use. When large volumes of 0.9% saline are administered, three critical problems emerge:

Hyperchloremic Acidosis and Renal Dysfunction

  • Administration of large volumes of 0.9% saline causes hyperchloraemic acidosis, renal vasoconstriction, and acute kidney injury 1
  • In a propensity-matched cohort of 22,851 surgical patients, hyperchloremia occurred in ~20% and was associated with increased 30-day mortality 1
  • The SALT trial demonstrated that patients receiving large volumes of 0.9% saline had higher rates of major adverse kidney events (MAKE), including death, need for renal replacement therapy, and persistent renal dysfunction 1

Volume-Dependent Toxicity

The evidence reveals a dose-response relationship between saline volume and adverse outcomes 1. This is particularly relevant for endoscopic procedures where irrigation volumes can be substantial:

  • Studies showing no difference between saline and buffered solutions had a critical limitation: patients received only small amounts of fluid 1
  • A registry study of >30,000 patients undergoing major abdominal surgery showed fewer complications with buffered crystalloids compared to 0.9% saline 1
  • One trial comparing buffered solutions to saline in major abdominal surgery was terminated prematurely due to increased vasopressor requirements in the saline group 1

Specific Endoscopic Context

Research specific to endoscopic procedures reveals additional concerns:

Plasma Volume Expansion

A 2023 study demonstrated that isotonic saline causes twice the plasma volume expansion compared to electrolyte-free irrigating fluids 2. When 1.25 L was infused:

  • Saline distributed slower (half-life 10.6 min vs. 6.5 min)
  • Saline was excreted four times slower (elimination half-life 87 min vs. 21 min)
  • This creates greater risk of cardiovascular overload, the most common adverse effect when saline is absorbed during endoscopic surgery 2

Fluid Overload Complications

Both excessive and insufficient fluid administration cause organ dysfunction 1:

  • Excessive fluid: AKI, ileus, worsening congestive cardiac failure, respiratory failure, tissue edema
  • High-risk patients have lower fluid tolerance and higher risk of fluid accumulation 1

Evidence-Based Recommendations

Primary Recommendation

Use buffered crystalloid solutions (lactated Ringer's or Plasmalyte) instead of 0.9% saline for endoscopic procedures requiring significant irrigation volumes 1

The 2024 guidelines state: "Based on the existing evidence and the possible existence of a dose-response relationship between the volume of 0.9% saline and adverse outcomes, buffered intravenous solutions are recommended in the perioperative period" 1

Supporting Evidence for Buffered Solutions

  • A 2025 study in sepsis-induced hypotension showed lactated Ringer's vs. saline resulted in:
    • Adjusted hazard ratio for death of 0.71 (95% CI 0.51-0.99; p=0.043) 3
    • 1.6 more hospital-free days at 28 days 3
    • Lower serum chloride and better bicarbonate levels 3

Critical Caveats

  1. Monitor fluid balance meticulously: The goal is maintaining intravascular euvolaemia—the "green zone" between hypovolemia and fluid overload 1

  2. Patient-specific risk factors matter:

    • High-risk patients (cardiac disease, renal dysfunction, elderly) have lower fluid tolerance 1
    • These patients are at higher risk of fluid accumulation even with moderate volumes

  3. Avoid the "small volume fallacy": Studies showing equivalence between saline and buffered solutions used median volumes of only 1000-1900 mL 4. This does not apply to high-volume endoscopic irrigation.

  4. Systemic absorption risk: During endoscopic procedures, irrigating fluid can be systemically absorbed, making the choice of solution even more critical 2

Practical Algorithm

For endoscopic procedures requiring >2 L irrigation:

  • First-line: Buffered crystalloid (lactated Ringer's or Plasmalyte)
  • Monitor: Serum chloride, bicarbonate, creatinine
  • Avoid: 0.9% normal saline as primary irrigant

For procedures requiring <1 L irrigation:

  • Either buffered crystalloid or saline acceptable
  • Still prefer buffered solution in high-risk patients (renal disease, cardiac disease, elderly)

If hyperchloremia develops (Cl⁻ >110 mEq/L):

  • Switch immediately to buffered crystalloid
  • Monitor for metabolic acidosis
  • Assess renal function

The evidence is clear: when volume matters, solution composition matters more.

References

2
Research

Isotonic saline causes greater volume overload than electrolyte-free irrigating fluids.

Journal of basic and clinical physiology and pharmacology, 2023

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.