The Mountain Model of Hyponatremia

“The Mountain Model of Hyponatremia” is an educational project byJoel Topf and me.Imagine this is the clinical scenario of severe hyponatremia:You are driving in a car at the top of a mountain. (The top of the mountain is the low sodium level.) There is a forest fire behind you. (The fire represents brain swelling and seizures if the sodium level drops much lower.)Your goal is to drive safely to the bottom of the mountain. (The bottom of the mountain is a normal sodium level.)But, to be safe, you must follow the  “sodium speed limit”: a rise in sodium of 8 every 24 hours. (If you exceed this “sodium speed limit,” you increase the risk of a car crash:osmotic demyelination syndrome.)Based on this model, there are five possible therapies for patients with hyponatremia: Press the accelerator (when the car is in “drive” ): 3% (hypertonic) salinePress the accelerator (but the car may be in “drive,” “neutral,” or even “reverse”): 0.9% (normal) salineCruise control: desmopressin/DDAVP and 3% (hypertonic) saline ( “proactive strategy”)Press the brake: desmopressin/DDAVP (or large amounts of D5W) ( “reactive strategy”)Reverse gear: desmopressin/DDAVP and D5W ( “rescue strategy”)Additional technical notes:The  “sodium speed limit” might change depending on the clinical situation.The slope of the mountain represents rapid correction due to water diuresis that can occur in patients with a reversible c...
Source: Kidney Notes - Category: Urology & Nephrology Authors: Source Type: blogs