Diabetic Ketoacidosis

Question 1

What is diabetic ketoacidosis (DKA)?

Answer 1

An acute metabolic complication of diabetes that is potentially fatal and requires prompt medical attention for successful treatment. It is characterised by absolute insulin deficiency and is the most common acute hyperglycaemic complication of type 1 diabetes mellitus.

Question 2

What risk factors are associated with DKA?

Answer 2

• Infection
  
  • Pneumonia and UTI
• Discontinuation of insulin (unintentional or deliberate)
• Inadequate insulin
  
  • Malfunctioning insulin pen or pump and
    degradation of insulin due to storage at incorrect temperature
• New onset diabetes
• Acute illness
  
  • Myocardial infarction, sepsis and pancreatitis
• Drug history
  
  • Corticosteroids, thiazides, sympathomimetics, cocaine, cannabis, and acute intoxication with alcohol
• Physiological stress
  
  • Pregnancy

Question 3

What are the signs of DKA?

Answer 3

• Acetone smell on breath
• Hyperventilation

Question 4

What are the symptoms of DKA?

Answer 4

• Known diabetes or features of diabetes e.g. increased thirst, polyuria, recent unexplained weight loss or excessive tiredness
• Nausea and vomiting
• Abdominal pain
• Dehydration
• Reduced consciousness

Question 5

What investigations should be ordered for DKA?

Answer 5

• Venous blood gas
• Blood ketones
• Blood glucose
• Urea and electrolytes
• FBC

Question 6

What are the parameters for diagnosing DKA?

Answer 6

• Blood ketones are ≥3.0 mmol/L OR there is ketonuria (more than 2+ on standard urine sticks); AND
• Blood glucose is >11.1 mmol/L OR known diabetes; AND
• Bicarbonate (HCO3-) is <15.0 mmol/L AND/OR venous pH is <7.3.

Question 7

Why investigate using venous blood gas? And what may this show?

Answer 7

• Use the pH to determine the severity of DKA:
  
  • pH ≥7.0 indicates mild or moderate DKA
  • pH <7.0 indicates severe DKA
• Metabolic acidosis with a raised anion gap

Question 8

Why use venous blood gas rather than arterial blood gas?

Answer 8

Venous blood gas testing may have a lower risk of serious adverse events (e.g., vascular occlusion or infection), is less painful for the patient, and is technically easier to perform than arterial blood gas testing.

Question 9

Why investigate blood ketones? And what may this show?

Answer 9

• Assessment of ketones should be done at or near the bedside, use urinary ketones if blood is not available
• Ketonaemia (ketones ≥3.0 mmol/L)

Question 10

Why investigate blood glucose? And what may this show?

Answer 10

• Assessment of glucose should be done at or near the bedside
• Hyperglycaemia (blood glucose >11.1 mmol/L)

Question 11

Why investigate urea and electrolytes? And what may this show?

Answer 11

• Hyponatraemia and hyperkalaemia are common but hypokalaemia is an indicator of severe DKA
• May show hypomagnesaemia and hypophosphataemia

Question 12

Why investigate FBC? And what may this show?

Answer 12

• Leukocytosis is common in DKA and correlates with blood ketone levels

Question 13

What are the 4 aspect which need to be managed in DKA treatment?

Answer 13

1. IV fluid
2. Potassium
3. Insulin
4. Resolution

Question 14

Briefly describe the IV fluid treatment of DKA

Answer 14

Question 15

Briefly describe the treatment of potassium in DKA

Answer 15

Question 16

Why should IV fluids be given before insulin?

Answer 16

Insulin treatment prior to adequate fluid replacement may cause cardiovascular collapse

Question 17

Briefly describe insulin therapy in DKA

Answer 17

Question 18

Briefly describe the resolution part of DKA treatment

Answer 18

Question 19

What complications are associated with DKA?

Answer 19

• Hypokalaemia
• Hypokalaemia
• Arterial or venous thromboembolic events

Question 20

What differentials should be considered for DKA?

Answer 20

1. Hyperosmolar hyperglycaemic state (HSS)
2. Lactic acidosis
3. Starvation ketosis
4. Alcoholic ketoacidosis

Question 21

How does DKA and hyperosmolar hyperglycaemic state (HSS) differ?

Answer 21

• Differentiating signs and symptoms: patients are typically older than patients with DKA and are usually patients with type 2 diabetes. Symptoms evolve insidiously over days to weeks. Mental obtundation and coma are more frequent.
• Differentiating investigations:
  
  • Serum glucose is >33.3 mmol/L (>600 mg/dL);
  • Serum osmolality is usually >320 mmol/ kg (>320 mOsm/kg);
  • Urine ketones are normal or only mildly positive and serum ketones are negative;
  • ABG: arterial pH is typically >7.30, whereas in DKA it ranges from 7.00 to 7.30

Question 22

How does DKA and lactic acidosis differ?

Answer 22

• Differentiating signs and symptoms: the presentation is identical to that of DKA. In pure lactic acidosis, the serum glucose and ketones should be normal and the serum lactate concentration should be elevated.
• Differentiating investigations: serum lactate >5 mmol/L.

Question 23

How does DKA and starvation ketosis differ?

Answer 23

• Differentiating signs and symptoms: starvation ketosis results from inadequate carbohydrate availability resulting in physiologically appropriate lipolysis and ketone production to provide fuel substrates for muscle.
• Differentiating investigations: the blood glucose is usually normal. Although the urine can have large amounts of ketones, the blood rarely does. Arterial pH is normal and the anion gap is at most mildly elevated.

Question 24

How does DKA and alcoholic ketosis differ?

Answer 24

• Differentiating signs and symptoms: classically, these are people with long-standing alcohol use disorder for whom ethanol has been the main caloric source for days to weeks. The ketoacidosis occurs when for some reason alcohol and caloric intake decreases.
• Differentiating investigations: in isolated alcoholic ketoacidosis, the metabolic acidosis is usually mild to moderate in severity. The anion gap is elevated. Serum and urine ketones are always present. Blood alcohol may be undetectable and the patient may be hypoglycaemic