Normal Saline

Indications

Intravenous (IV)

Hypovolemic Hyponatremia (see Hyponatremia

  • Clinical Efficacy
    • Single-Center, Multiple-Crossover SALT-ED Trial of Balanced Crystalloids vs Normal Saline in Non-Critically Ill Adults in the Emergency Department (NEJM, 2018) [MEDLINE]: n = 13,347
      • Among noncritically ill adults treated with intravenous fluids in the emergency department, there was no difference in hospital-free days between treatment with balanced crystalloids and treatment with saline

Anaphylaxis (see Anaphylaxis)

  • Clinical Efficacy

Hemorrhagic Shock (see Hemorrhagic Shock)

  • Clinical Efficacy

Hypovolemia/Hypovolemic Shock (see Hypovolemic Shock)

  • Clinical Efficacy
    • Single-Center, Multiple-Crossover SALT-ED Trial of Balanced Crystalloids vs Normal Saline in Non-Critically Ill Adults in the Emergency Department (NEJM, 2018) [MEDLINE]: n = 13,347
      • Among noncritically ill adults treated with intravenous fluids in the emergency department, there was no difference in hospital-free days between treatment with balanced crystalloids and treatment with saline

Sepsis (see Sepsis, [[Sepsis]])

  • Clinical Efficacy
    • Cluster-Randomized, Multiple-Crossover SMART-MED and SMART-SURG Trial of Balanced Crystalloids vs Normal Saline in Critically Ill Adults (NEJM, 2018) [MEDLINE]: n = 7942 (5 ICU’s)
      • Balanced Crystalloids (Lactated Ringers or Plasma-Lyte) for Intravenous Fluid Resuscitation Decreased the Composite Outcome of All-Cause Mortality Rate, Need for New Renal Replacement Therapy, and Persistent Renal Dysfunction, as Compared to Normal Saline

Subcutaneous (SQ)

Other

  • Nasal Irrigation: in the setting of sinusitis
  • Ocular Irrigation: in the setting of ocular exposures
  • Wound Irrigation: does not burn or sting when used

Pharmacology

Definitions

  • Crystalloids: sodium-based electrolyte solutions

History of Crystalloids

  • 1831 (Europe): first clinical use of crystalloids during the India Blue Cholera pandemic
  • 1896 (Holland): Hartog Hamburger (Dutch physiologist) invented “normal saline”: he intended to use this fluid in the in vitro study of erythrocyte lysis
  • 1880 (England): Sydney Ringer invented “Ringer’s solution”: he used this fluid to sustain contractility in isolated frog hearts
    • The fluid was inadvertently made with tap water (instead of distilled water) and the inadvertent presence of calcium likely led to the experiment being successful
    • Ringer analyzed the fluid and found that it contained calcium, sodium, potassium, chloride, and magnesium
  • 1930’s (USA): pediatrician Alexis Hartmann added lactate to a solution very similar to Ringer’s solution, creating a forerunner of “Lactated Ringer’s” (see Lactated Ringers): lactate was added by Hartmann to “buffer” the solution (creating a “balanced” solution)

Balanced vs Unbalanced Crystalloids

  • Balanced Crystalloids: mildly hypotonic lactate or acetate buffered solutions (with signficantly lower chloride concentrations than saline)
    • Lactated Ringer’s (LR) (see Lactated Ringers)
    • Acetate Ringer’s
    • Hartmann Solution
    • Plasma-Lyte (from Baxter Healthcare)
  • Unbalanced Crystalloids : contain no buffer (note: additionally, normal saline has higher chloride concentration than the above)
    • Normal Saline (NS): 0.9% NaCl
    • Half Normal Saline (see Half Normal Saline): 0.45% NaCl
    • Quarter Normal Saline (see Quarter Normal Saline): 0.22% NaCl
    • Dextrose 5% in Water (D5W) (see Dextrose 5% in Water): Dextrose 5%
    • D5 Normal Saline (D5NS): Dextrose 5% + 0.9% NaCl
    • D5 Half Normal Saline (D5 1/2NS): Dextrose 5% + 0.45% NaCl
    • D5 Quarter Normal Saline (D5 1/4NS): Dextrose 5% + 0.22% NaCl
  • Comparative Data
    • Use of balanced crystalloid is associated with decreased kidney pathology in rat model of hemorrhagic shock, as compared to unbalanced crystalloid [MEDLINE]
    • Chloride-restrictive IV fluid resuscitation strategy is associated with decreased renal injury [MEDLINE]: may be related to hyperchloremia’s induction of renal vasoconstriction

Composition of Various Intravenous Fluids

  • Normal Saline Has a Slightly Higher Osmolarity than Serum (Serum Osmolarity is Approximately 280-310 mOsm/L): however, taking into account the osmotic coefficient (which corrects for non-ideal solutions), normal saline is close to isotonic with blood

Administration

  • IV:

Adverse Effects

Cardiovascular Adverse Effects

Renal Adverse Effects

Other Adverse Effects

  • Exacerbation of Cirrhotic Ascites (see Ascites)

References

  • Rapid saline infusion produces hyperchloremic acidosis in patients undergoing gynecologic surgery. Anesthesiology. 1999 May;90(5):1265-70 [MEDLINE]
  • Association between a chloride-liberal vs chloride-restrictive intravenous fluid administration strategy and kidney injury in critically ill adults. JAMA. 2012 Oct 17;308(15):1566-72. doi: 10.1001/jama.2012.13356 [MEDLINE]
  • Balanced vs unbalanced crystalloid resuscitation in a near-fatal model of hemorrhagic shock and the effects on renal oxygenation, oxidative stress, and inflammation. Resuscitation. 2012 Jun;83(6):767-73. doi: 10.1016/j.resuscitation.2011.11.022. Epub 2011 Dec 4 [MEDLINE]
  • The ideal crystalloid – what is ‘balanced’? Curr Opin Crit Care. 2013 Aug;19(4):299-307. doi: 10.1097/MCC.0b013e3283632d46 [MEDLINE]
  • Crystalloids for Fluid Resuscitation in Sepsis: Where Is the Balance? Ann Intern Med. 2014 Jul 22. doi: 10.7326/M14-1565 [MEDLINE]
  • Balanced Crystalloids versus Saline in Noncritically Ill Adults. N Engl J Med. 2018 Mar 1;378(9):819-828. doi: 10.1056/NEJMoa1711586 [MEDLINE]
  • Balanced Crystalloids versus Saline in Critically Ill Adults. N Engl J Med. 2018 Mar 1;378(9):829-839. doi: 10.1056/NEJMoa1711584 [MEDLINE]