I recently wrote a chapter on DKA and really fell in love with the topic all over again. It reminded me of an interesting patient with a unique variant of DKA. First off, it was the patient’s initial presentation of diabetes. A rare, but not unheard of, presentation of DKA in adults.
But what was really remarkable was that the patient presented with a blood sugar of over 1500 mg/dL (>83.3 mmol/L). The lab kept refusing to result out the BMP due to the crazy sodium and the poor ER docs were going crazy. They suspected the diagnosis but they were holding back on the insulin drip until they could see the BMP. I wonder if the clinical scenario had not been so dire, would the lab have actually resulted out a specific glucose? How many dilutions does it take to calculate a blood glucose when you are operating at over 1500 mg/dL?
The sodium on arrival was 145 with the high glucose that converts to 167 using Katz’s conversion. But god knows if that equation even works way up there with a serum osmolality of 452!
Using a serum glucose of 1500 mg/dl gives an osmolar gap of 54, that sounds awfully big. A glucose of 2000 gives a more reasonable osmolar gap of 26.
Watch the video and you will see that the sodium creeps up bit by bit during the resuscitation. This is largely due to ongoing fluid losses (osmotic diuresis) and unmasking the hypernatremia with the correction of the hyperglycemia. We calculated a free water deficit when the sodium hit 170 and it was over 7 liters.
Here is the tweet
The video
The keynote slides: Hyperglycemia DKA Hypernatremia