I had my first experience starting someone on an insulin drip recently. Being on night shift I came in on one of my first shifts and received sign out that I had a patient who was having difficult to control sugars (she actually wasn’t in DKA–she didn’t meet full criteria) and may need to be started on an insulin drip over night. However, I thought reviewing DKA fit well!
What is DKA?
DKA stands for Diabetic Ketoacidosis. It is a complication of diabetes that by the books occurs in type 1 diabetics. However, it is frequently seen as a complication of type 2 diabetics. Text books will also tell you that this frequently occurs with new onset diabetes–which it does. However, more commonly patients will present with severe non-compliance with their insulin regimen.
So, we all know this will cause the blood glucose (BG) levels of someone with diabetes to sky rocket. When I first learned about DKA and all of the other snowball effects dangerously high glucose can have on the body I was surprised (this was back in didactic year–not just now haha).
Because of the hyperglycemic state of DKA, in addition to glycogenolysis and hepatic gluconeogenesis and lipolysis. The liver metabolizes free fatty acids (aka ketogenesis) resulting in the production of ketones. The most specific ketone to test for DKA is beta-hydroxybutyrate. The over production of ketones causes a shift in the body’s pH to become acidic producing a rise in the anion gap. Patients may also present with disturbance in potassium and bicarb. Fluid and electrolyte deficits are usually quite significant.
When this process occurs inside the body and a state of metabolic acidosis is entered signs and symptoms of nausea, vomiting, fruity breath, malaise, psychological distress/AMS and fever.
All of this background (which is by no means comprehensive but just a little touch up on DKA) leads us to how the heck is something so complex managed?
Necessary workup includes tight BG measurement (Q1h), frequent BMP’s, initial ABG and renal function. An additional important consideration is constant telemetry and obtaining EKG due to electrolyte disturbances.
The most important aspects of DKA management are insulin replacement, which should begin with a bolus dose of fast acting insulin at anywhere between .1-.4u/kg and then establish an hourly drip rate between .1-.4u/kg/hr. Replacement of bicarb (if indicated) and constant fluids (1-3L in first hour, 1L during second hour and 1L Q4h. Potassium levels will generally be elevated upon presentation due to hyperglycemic state (lack of insulin will keep K+ outside of cells and available to serum levels). Once potassium hits around 3.5-4, generally potassium is repleted to avoid hypokalemia. Along the same lines, once BG levels hit 250–begin administering dextrose 10-20mEq/L. Bicarb replacement is reserved for life threatening levels–meaning patient is in serious life threatening condition. Generally speaking patients are usually in the ICU and are then transferred to a step down unit or med/surg floor. Cases are all very independent.
Hopefully this was a quick and dirty review for whenever you have to start your first insulin drip! Give insulin, replace fluids and electrolytes, get an ABG, ICU and frequent monitoring in a nut shell 🙂