NBME 22 Answers ↦
While you will have a high serum potassium, your total body potassium will be low due to very low intracellular potassium (which is where the majority of the body's potassium is usually).
This is why you give potassium to patients with DKA
Why do you not get an increased bicarbonate concentration?
Bicarb acts as a buffer and binds up excess H+ in DKA
I know Insulin cause shift K+ into cells due to closing of ATP-sensitive K channels (blocking K from leaving)? Does it increase K in the cells by another mechanism?
@dentist - Insulin stimulates the Na+-K+-ATPase pump, this drives K+ into the cell (Source: Amboss)
Another mechansim = acidosis causes hyperkalemia due to H+/K+ antiporters. H+ is high in blood so shifts into cells via this antiporter, which shifts K+ out. --potassium section of acid/base chapter in Costanzo physiology
super high blood glucose; super high glucose spillage into urine; lots of peeing = volume depleted (“osmotic diuresis”)
because insulin normally stimulates Na/K ATPase, which sequesters K inside cell. lack of insulin means that there will be more K outside of the cell causing hyperkalemia. however, you are still total body K depleted due to osmotic diuresis. so the hyperkalemia is mainly due to a shift of K from the intracellular (where the vast majority of your K is inside your body is) to the extracellular space.
*where the vast majority of your K is inside your body