1.2 MTB Step 3 - Type 1 Diabetes Mellitus & DKA

Question 1

TYPE 1 DIABETES

What is Type 1 Diabetes Mellitus ALWAYS the result of?

Answer 1

Underproduction of INSULIN

Question 2

TYPE 1 DIABETES

What is the (suspected) Cause of Type 1 Diabetes Mellitus?

Answer 2

The Pancreas is Destroyed during Childhood on an Autoimmune/Genetic basis.

Question 3

DIABETIC KETOACIDOSIS (DKA)

How does DKA typically present?

Answer 3

• Extremely ill patient with Hyperventilation as compensation for the Metabolic Acidosis (low bicarbonate).
• “Fruity” odor of the breath from acetone.
• +/- confusion from the hyperosmolar state.

Question 4

DIABETIC KETOACIDOSIS (DKA)

What is the Best INITIAL Diagnostic Test for Diabetic Ketoacidosis (DKA)?

Answer 4

Serum Bicarbonate + Anion Gap = Best way to determine the Severity of illness.

• A Low Serum Bicarbonate implies an Elevated Anion Gap, and this is the Marker for Severe DKA.

Question 5

DIABETIC KETOACIDOSIS (DKA)

What Lab Value can also be obtained as a Marker of Ketone production?

Answer 5

Beta-Hydroxybutyrate

As you correct the Ketoacidosis, the Beta-Hydroxybutyrate level should decrease.

Question 6

DIABETIC KETOACIDOSIS (DKA)

What are the common lab values in Diabetic Ketoacidosis?

Answer 6

• Hyperglycemia (> 250): Very High Glucose artificially drops Sodium (Na) level.
• Hyperkalemia: Initially there will be hyper kalemia. If there is no insulin, potassium builds up outside the cell. The hyperkalemia will quickly translate into hypokalemia as you treat the DKA. So it is very important to make sure you supplement with potassium.
• Decreased Serum Bicarbonate
• Low pH, with Low pCO2 as Respiratory Compensation
• Elevated Acetone, Acetoacetate, and Beta-Hydroxybutyrate levels
• Elevated anion gap
• Pseudohyponatremia caused by high glucose

Question 7

DIABETIC KETOACIDOSIS (DKA)

BASIC SCIENCE CORRELATE

What is the Mechanism of Hyperkalemia in DKA?

Answer 7

• Hyperkalemia in DKA is from Transcellular Shirt of Potassium (K) out of the cell in Exchange for Hydrogen (H) ions going into the cell.
• The cells “suck up acid (H+)” as a way of compensating for the severe metabolic acidosis and release potassium (K) in exchange.
• Also, Insulin drives Potassium (K) into cells with Glucose.

*HYPERkalemia = Acidosis

**“HYPOkalemia = Alkalosis

Question 8

DIABETIC KETOACIDOSIS (DKA)

BASIC SCIENCE CORRELATE

What is the Mechanism of Elevated Anion Gap in DKA?

Answer 8

• Most cells need Insulin to use Glucose as fuel.
• In the Absence of insulin, Glucose can’t enter the cells, so the cells look for Alternative fuel sources.
• Free Fatty Acids (FFAs) and Ketones are the Alternative fuel sources.
• KETONES are Negatively charged Acids, so using them as fuel Decreases the level of Bicarbonate

Question 9

DIABETIC KETOACIDOSIS (DKA)

1. What therapy should be administered at the same time as ordering labs for a patient with suspected DKA?
2. What therapy should be administered once Hyperglycemia and Low Bicarbonate are found on initial labs?
3. What therapy should be added once the Potassium (K) level drops into the Normal Range?

Answer 9

1. Normal Saline (Bolus)
2. Insulin (IV)
3. Potassium (add to IVF)

• High Glucose + Low Bicarb = DKA ⇒ give NS bolus and IV Insulin*
• Acidic environment drives K out of cells. Insulin drives insulin into cells. When acidosis start to correct, more K goes into cells creating Hypokalemia (this is why you add K when level reaches normal range)*