Management of Diabetic Ketoacidosis (DKA) and Hyperosmolar Hyperglycemic State (HHS) in Adults

This is the common internal medicine problem that will keep me quite busy if it rolls in on night float...or anytime of the day, I suppose.

Definitions 

• DKA - metabolic acidosis, secondary to ketones, is often the major finding, while the serum glucose concentration is generally below 800 mg/dL. 
• In HHS, there is little or no ketoacid accumulation, the serum glucose concentration frequently exceeds 1000 mg/dL, the serum osmolality may reach 380 mosmol/kg.

Initial Evaluation

• Take care of your ABCs first! (Airway,Breathing and Circulation)
• Establish a diagnosis with CBC, BMP, UA for ketones, ABG, plasma osmolality
• Try to find the underlying etiology of the DKA or HHS and treat that. Most are secondary to infection (pneumonia and UTI) so obtain blood cultures, chest xray and EKG

Monitoring

Once you have established the diagnosis, how should you monitor?

•  Serum glucose should initially be measured every hour until stable, while serum electrolytes, blood urea nitrogen, creatinine, osmolality, and venous pH, which is about 0.03 units lower than arterial blood gas, should be measured every two to four hours, depending upon disease severity and the clinical response. 
• Monitor the acidosis by either directly measuring beta-hydroxybutyrate or the anion gap.

Treatment

• FLUIDS!! - Fluids should be given first as it increases the effectiveness of the insulin therapy to come. Initial fluid therapy in DKA and HHS is directed toward expansion of the intravascular volume and restoration of renal perfusion. The average fluid loss is 3 to 6 L in DKA and up to 8 to 10 L in HHS, due largely to the glucose osmotic diuresis . Start with NS and switch over to D5NS when the serum glucose is <250. As mentioned below, if the patient is hemodynamically stable, then you will want to switch to 1/2NS when adding potassium to the fluid.
• Replenish the Potassium - To prevent hypokalemia, potassium chloride (20 to 30 meq/L) is generally added to the replacement fluid once the serum potassium concentration falls below 5.3 meq/L. If the patient is hemodynamically stable, one-half isotonic saline is preferred since the addition of potassium to isotonic saline will result in a hypertonic solution that will delay correction of the hyperosmolality.
• Insulin of course!! - After you have given fluids and serum potassium is > 3.5, you may give insulin. A continuous IV administration of regular insulin is the treatment of choice. DKA and HHS can be treated either with an IV bolus (0.1 U/kg body weight), followed by a continuous infusion of regular insulin at a dose of 0.1 U/kg per hour or with an intravenous infusion alone at a rate of at least 0.14 U/kg per hour.
• Sodium Bicarbonate - We recommend administering bicarbonate if the arterial pH is less than 6.90. UptoDate recommends giving 100 meq of sodium bicarbonate in 400 mL sterile water with 20 meq of potassium chloride, if the serum potassium is less than 5.3 meq/L, administered over two hours.