Introduction

Case Presentation

  • MJ is a 56-year-old female who presents to the ED with a chief complaint of progressively worsening weakness and fatigue over the past week, associated with a loss of appetite, nausea, and occasional confusion.
    • MJ denies shortness of breath, chest or abdominal pain, cough, pain or swelling in her legs, other neurological symptoms, fever, vomiting, or diarrhea.
    • Her medical history is significant for hypothyroidism, hypercholesterolemia, and hypertension.
    • According to family, she was hospitalized for three days a few months ago due to “dehydration,” at which time she was given “fluids.”
    • While transporting MJ to the CT scanner, she has a witnessed prolonged tonic-clonic seizure.
    • POC labs are unremarkable, except a serum sodium of 118 mEq/L.
  • How would you manage this patient?
    • 3% Sodium Chloride STAT!

Clinical Detail

Pharmacology — 3% Sodium Chloride (NaCl)

ParameterDetail
Dose*
  • 2 mL/kg or 50–150 mL
    • Maximum of 3 boluses of 3% NaCl, preferably 10–30 minutes apart
  • Option to dose based on the calculated sodium deficit
Administration*
  • IV bolus is the recommended administration for symptomatic hyponatremia
  • Administered over 10–60 minutes
  • May be given through peripheral (PIV) access while central access is obtained
Adverse Effects
  • Hypernatremia
  • Fluid or solute overload
  • Hypokalemia
  • Acidosis
  • Overcorrection of hyponatremia
Monitoring
  • BMP (Na+, K+, Cl−)
  • Symptoms of hyponatremia
  • Serum osmolality
  • Volume status
  • Neurological exam
Compatibility
  • Not compatible with blood products or with drugs that are incompatible with normal saline
Comments
  • Critical to establish IV access with the largest bore at the most proximal point
  • During emergencies, it is acceptable to administer through a peripheral IV

*Check institutional guidelines.

Keys to Managing Symptomatic Hyponatremia

ParameterDetail
Indications for emergency treatment
  • Confusion, agitation, coma, or seizures secondary to low serum sodium levels
  • Symptoms of severe hyponatremia
Goal Na+
  • Goal of a 5–6 mEq/L increase in serum sodium in the first 1–2 hours
  • Goal of 120 mEq/L initially, followed by slower correction to approximately 130 mEq/L over the following 24–48 hours
    • The initial goal serum sodium level should be lower if the baseline serum sodium is < 100 mEq/L

Evidence

Overview of Evidence

Author, yearDesign, sample sizeIntervention & comparisonOutcome
Dillon, 2018Observational
N = 66		3% NaCl through PIV
  • Max rate = 50 mL/hr
  • Mean infusion duration = 14 hrs (IQR 4–30)
  • Infusion-related phlebitis = 3%
Perez, 2017Observational
N = 28		3% NaCl through PIV
  • Max rate = 50 mL/hr
  • Mean infusion duration = 36 hrs (range 1–124)
  • Infusion-related phlebitis = 3%
Jones, 2016Observational
N = 213		3% NaCl through PIV
  • Max rate = 30 mL/hr
  • Mean infusion duration = 0.85 hr (IQR 0.4–1.3)
  • Infusion-related phlebitis = 4%
Ayus, 2015Case series
N = 47		3% NaCl 500 mL over 6 hrs via PIV
  • Increase in serum sodium of 1.26 mEq/L/hr
  • Improvement in symptoms in 97% of cases
Hew-Butler, 2015Exercise-Associated Hyponatremia (EAH) consensus guidelineRecommendation for severe EAH“100 mL bolus of 3% NaCl, repeated twice if there is no clinical improvement (10 min intervals have been recommended).”
Spasovski, 2014European Renal Best Practice (ERBP) hyponatraemia guidelineRecommendation for severe hyponatremia“We recommend prompt IV infusion of 150 mL 3% hypertonic saline or equivalent over 20 minutes. (1D)”
Verbalis, 2013Expert panel recommendations for hyponatremiaRecommendation for symptomatic acute hyponatremia“For severe symptoms, 100 mL of 3% NaCl infused IV over 10 minutes × 3 as needed.”

Conclusions

  • Severe symptomatic hyponatremia — confusion, agitation, coma, or seizures secondary to a low serum sodium — is a neurologic emergency; as in this case, the response is 3% sodium chloride STAT.
  • Give 3% NaCl as an IV bolus of 2 mL/kg or 50–150 mL, up to a maximum of 3 boluses preferably 10–30 minutes apart; a peripheral IV is acceptable during the emergency while central access is being obtained.
  • Target a 5–6 mEq/L rise in serum sodium over the first 1–2 hours, aiming for approximately 120 mEq/L initially and then slower correction to approximately 130 mEq/L over 24–48 hours; the initial goal should be lower if the baseline serum sodium is < 100 mEq/L.
  • Monitor closely — serial BMP (Na+, K+, Cl−), serum osmolality, volume status, and neurologic exam — and guard against overcorrection, hypernatremia, hypokalemia, fluid or solute overload, and acidosis.
  • Always check institutional guidelines.

References

  • Sodium chloride. Micromedex [Electronic version]. Greenwood Village, CO: Truven Health Analytics. Retrieved December 21, 2019, from http://www.micromedexsolutions.com/
  • Rogers IR, et al. Clin J Sport Med. 2011 May;21(3):200-3. PMID: 21519296
  • Dillon RC, et al. J Intensive Care Med. 2018 Jan;33(1):48-53. PMID: 28372499
  • Perez CA, et al. J Neurosci Nurs. 2017 Jun;49(3):191-195. PMID: 28471928
  • Jones GM, et al. Am J Crit Care. 2016 Dec;26(1):37-42. PMID: 27965228
  • Ayus JC, et al. Am J Kidney Dis. 2015 Mar;65(3):435-42. PMID: 25465163
  • Hew-Butler T, et al. Clin J Sport Med. 2015 Jul;25(4):303-20. PMID: 26102445
  • Spasovski G, et al. Nephrol Dial Transplant. 2014 Apr;29 Suppl 2:i1-i39. PMID: 24569496
  • Verbalis JG, et al. Am J Med. 2013 Oct;126(10 Suppl 1):S1-42. PMID: 24074529
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