Ketoacidosis

Question 1

What is Diabetic ketoacidosis?

Answer 1

Diabetic ketoacidosis (DKA) is a severe medical emergency characterized by the triad of:
1. Hyperglycemia (blood sugars >11 mmol/L)
2. Ketonemia (blood ketones >3 mmol/L)
3. Acidosis (pH <7.3 or bicarbonate <15 mmol/L)
Note: Patients on gliflozins can present with euglycemic DKA.

• More common in patients with type 1 diabetes → no insulin to suppress lipolysis → ketone formation → acidosis
• DKA may be the initial presentation in someone with undiagnosed T1DM

Question 2

What can cause diabetic ketoacidosis to occur as a complication of treatment/ management?

Answer 2

• Acute illness
• Missed insulin doses
• Inadequate insulin doses

Question 3

What are the risk factors for ketoacidosis?

Answer 3

• infection (most common precipitating factor)
• inadequate insulin therapy (non-compliance),
• undiagnosed T1DM
• MI:
• Infection/illness → increased cortisol (antagonist of insulin) → bodies insulin requirements increase ⇒ hence type 1 diabetics should make sure they continue taking insulin when they are unwell to prevent DKA
• ‘Sick Day Rules’ ⇒ continue normal insulin dose, check blood glucose more regularly, aim to drink 3L of fluid over 24hrs, self-monitor ketones regularly through day.

Question 4

How do you diagnose diabetic ketoacidosis?

Answer 4

pH <7.3, Serum ketones (beta-hydroxybutyrate) ≥3mmol/L (urine or capillary blood), HCO3- <15 mmol/L and glucose >11 mmol/L

Question 5

What are the presenting symptoms/ signs of diabetic ketoacidosis?

Answer 5

• Features of Diabetes → increased thirst (polydipsia), polyuria, weight loss, excessive tiredness
• Nausea & Vomiting
• Severe Abdominal Pain
• Dehydration → dry mucous membranes, decreased skin turgor, slow CRT, tachycardic, hypotensive
• Hyperventilation → kussmmaul breathing (decrease in pH stimulates respiratory centre to try and correct acidosis by blowing off CO2)
• Reduced Consciousness
• Fruity Breath
• Rapid Onset (<24 hrs)

Question 6

What investigations are used to diagnose/ monitor ketoacidosis?

Answer 6

1. VBG→ metabolic acidosis with raised anion gap (>16), with partial respiratory compensation (hyperventilation)
2. Blood Ketones → raised
3. Blood Glucose → raised
4. U&Es → hyponatraemia and hyperkalaemia (due to lack of insulin)

Question 7

How is ketoacidosis managed?

Answer 7

Two Key Parts to Treatment:

1. Rehydrate → IV Fluids (Isotonic Saline - 10ml/kg 0.9% NaCl)
   - Important complication of fluid resuscitation in DKA = cerebral oedema/ swelling of the brain parenchyma (may cause headache, reduced consciousness, rise in BP, seizures)
   - With Electrolyte repletion (especially K+ as insulin will drive it into cells) → Potassium Chloride
2. Reduce Ketones → fixed rate IV Insulin (0.1 units/kg/hour) (AFTER FLUIDS)
   - Once glucose falls, give 5% dextrose
   - Regular Insulin Medication ⇒ continue long acting insulin, stop short acting insulin
3. IV Bicarbonate → only in severe metabolic acidosis