Episode 60: Emergency Management of Hyponatremia

In this EM Cases episode Dr. Melanie Baimel and Dr. Ed Etchells discuss a simple and practical step-wise approach to the emergency management of hyponatremia:

1. Treat neurologic emergencies related to hyponatremia with hypertonic saline

2. Defend the intravascular volume

3. Prevent worsening hyponatremia

4. Prevent rapid overcorrection with the Rule of 100s

5. Ascertain the cause

Dr. Etchells and Dr. Baimel answer questions such as: What are the indications for giving DDAVP in the emergency management of hyponatremia? What is a simple and practical approach to determining the cause of hyponatremia in the ED? How fast should we aim to correct hyponatremia? What is the best fluid for resuscitating the patient in shock who has a low serum sodium? Why is the management of exercise associated hyponatremia counter-intuitive? What strategies can we employ to minimize the risk of Osmotic Demyelination Syndrome (OSD) and cerebral edema in the emergency management of hyponatremia? and many more...



Blog post and Written Summary Prepared by Dr. Michael Kilian, edited by Dr. Anton Helman, March 2015

Cite this podcast as: Baimel, M, Etchells, E, Helman, A. Emergency Management of Hyponatremia. Emergency Medicine Cases. March, 2015. https://emergencymedicinecases.com/episode-60-emergency-management-hyponatremia/. Accessed [date].

Hyponatremia is the most common fluid and electrolyte disorder encountered in clinical practice and is found in approximately 20% of admissions to hospital. In addition to being extremely prevalent, hyponatremia is an independent predictor of mortality.

There are two factors which influence how symptomatic a patient will become as a result of hyponatremia:



* Severity of hyponatremia

* Acuity of onset



The lower the sodium and the faster the fall, the more symptomatic a patient will become.

Symptoms are often vague and non-specific presenting as headache, irritability, lethargy, confusion, agitation or unstable gait leading to a fall.

Approach to Emergency Management of Hyponatremia

Conceived by Dr. Edward Etchells





Step-Wise Approach to Emergency Management of Hyponatremia

1. Treat Neurologic Emergencies Related to Hyponatremia

In the event of a seizure, coma or suspected cerebral herniation as a result of hyponatremia, IV 3% hypertonic saline should be administered as soon as possible according to the following guide:



* Administer 3% hypertonic saline 100-150cc IV over 5-10min

* If the patient does not improve clinically after the first bolus, repeat a second bolus of hypertonic saline.

* Stop all fluids after the second bolus of hypertonic saline to avoid raising the serum sodium any further



What if hypertonic saline is not readily available?

Administer one ampule of Sodium Bicarbonate IV over 5min.

2. Defend the Intravascular Volume

In order to defend the intravascular volume a determination an assessment of the patient’s volume status must occur. Is the patient hypovolemic, euvolemic or hypervolemic?

Although volume status is difficult to assess with any accuracy at the bedside, a clinical assessment with attention to the patient’s history, heart rate, blood pressure, JVP, the presence of pedal and sacral edema, the presence of a postural drop (helpful in Dr. Etchell’s opinion) and point-of-care ultrasound (POCUS) is usually adequate to make a rough determination of whether the p...