Written by: Brandon Fetterolf, DO and edited by: Van Wall, DO

CC: Seizures

HPI: 35M found seizing by family member. No other details known surrounding event. Tonic/clonic movements ongoing for greater than 30 minutes (Status Epilepticus).

Relevant vitals/PMH/meds/allergies:  None

Work up:  POCT dextrose, I-stat, EKG, CT head, CBC, CMP, Lactate, U Tox, hCG prn

Patient given two doses of Ativan with continued seizure activity. Dextrose 110.

Differential Diagnoses:

Trauma, ICH, brain mass, toxins/exposure, overdose, withdrawal, infection (also think travel history), tachydysrhythmia/ACS (brain hypoperfusion resulting in seizure activity), electrolyte abnormality, hypoglycemia, drugs of abuse, eclampsia, endocrine (thyroid storm, etc), primary seizure disorder, pseudo seizure, medication side effect.

Labs: Na 114

Diagnosis:  atypical seizure secondary to hyponatremia

What we learned from the case:

Administering NaHCO3 to rapidly correct hyponatremia is a reasonable alternative when 3% hypertonic saline is not readily available.

Key points to the diagnosis, treatment, dispo, etc.

-Establish the safety net ASAP and consider airway management.  Get a d-stick immediately on all seizure patients.  As always, it is appropriate to try first-line therapy to control the seizure – benzos. When these fail, quickly consider alternative etiologies as listed above and rapidly reassess the ABCs.

-Basic treatment with hypertonic saline: 100ml 3% NaCl (or 2mL/kg) over approximately 10 min (may be slow push) and may repeat this x 2 q 10 min (total of three doses) if patient continues to seize per Nephrology literature and expert opinion.

-Keep in mind NaHCO3 is a hypertonic saline solution.  In this case, hypertonic saline was not readily available so NaHCO3 was pulled from the crash cart.

-Typical US crash carts carry 8.4% sodium bicarb which is 1 mEq/mL.  As an alternative to hypertonic saline, you may consider 1mL/kg or 1-2 amps of 8.4% NaHCO3.  Avoid dosing errors by adjusting amount given based on the concentration  your hospital carries (5%, 8.4%, isotonic gtt, etc.)!

From EMCrit.org:


-Okay to use in well-placed peripheral line (avoid deep brachial lines as they often infiltrate).  Central Venous Catheter not necessary immediately!

-Use DDAVP in hypovolemic, hyponatremic patients to prevent overcorrection of hyponatremia in patients you want to volume resuscitate. During volume resuscitation, perfusion eventually improves which shuts off vasopressin and the kidneys rapidly excrete water, causing a dangerously fast normalization of the serum sodium

–DDAVP results in renal retention of water and helps to prevent its unpredictable excretion.

-This should be given during or shortly after hypertonic solution.

From EMCrit.org:taking-control-of-severe-hyponatremia-with-ddavp_-Dr. Gorbatkin added, “I think is  very reasonable to use DDAVP to avoid overcorrection in the case. The lower the Na, the more compelling the case to use DDAVP right from the start. It is also more compelling if the volume status is unknown, or if it is unclear how much water diuresis might be induced with acute intervention.

A now more historic article:

Neurologic sequelae after treatment of severe hyponatremia: a multicenter perspective. JASN February 1, 1994 vol. 4 no. 8 1522-1530
uses Na of 105 or lower as a level for highest concern over overcorrection, but at the time the article was written the literature was setting a goal of correction of  12 mmol/L or less per 24 hrs. Now the goal is 6-8 mmol/L over the first 24 hrs if the time period of development of hyponatremia is not known.”


Contributors: Dr. Strode, C., Dr. Gorbatkin, S. Dr. Gorbatkin, C.

Other useful resources/links:

Am J Med. 2015 Dec;128(12):1362.e15-24. Desmopressin to Prevent Rapid Sodium Correction in Severe Hyponatremia: A Systematic Review. MacMillan TE1Tang T2Cavalcanti RB3.

EMCrit Podcast 39 – Hyponatremia

Emergent treatment of hyponatremia or elevated ICP with bicarb ampules

Taking control of severe hyponatremia with DDAVP

Special Seizures

Wendy Chang: Status Epilepticus Mistakes You Don’t Want to Make!