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:
-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:
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 TE1, Tang T2, Cavalcanti RB3.
A collection of interesting cases and clinical images in Emergency Medicine. 