What is Diabetic Ketoacidosis?
Introduction
Diabetic Ketoacidosis is a medical emergency and remains a serious cause of morbidity, principally in people with type 1 diabetes
Risk Factors for Diabetic Ketoacidosis
- Type 1 Diabetes
- Cerebral oedema in children and adolescents
- Hypokalaemia
- Acute respiratory distress syndrome
- Acute myocardial infarction
- Sepsis
- Pneumonia
Pathogenesis of Diabetic Ketoacidosis
- Cardinal Biomechanical features
- Hyperketonemia (>3 mmol/L)
- Ketonnuria (>2 on standard urine sticks)
- Hyperglycaemia (blood glucose >11 mmol/L or >200mg/dL)
- Metabolic acidosis (venous bicarboate <15mmol/L and Venous pH <7.3)
- Hyperglycaemia causes profound osmotic diuresis leading to dehydration and electrolyte loss, particularly Potassium and Sodium
- Potassium loss is exacerbated by secondary hyperaldosteronism due to reduced renal perfusion
- Ketosis result from insulin deficiency exacerbated by elevated catecholamines and other stress hormones
- Due to more unmetabolized acidic ketones, it starts accumulating in blood
- Metabolic acidosis forces hydrogen ions into cells, displacing potassium ions
Clinical Feature of Diabetic Ketoacidosis
Symptoms of Diabetic Ketoacidosis
- Polyuria, Thirst
- Weight loss
- Weakness
- Nausea, Vomitting
- Leg cramps
- Blurred vision
- Abdominal pain
Signs of Diabetic Ketoacidosis
- Dehydration
- Hypotension (Postural or Supine)
- Cold extremities / Peripheral cyanosis
- Tachycardia
- Air hunger (Kussmaul breathing)
- Smell of Acetone
- Hypothermia
- Confusion / Drowsiness / Coma
Investigations for Diabetic Ketoacidosis
- Venous blood: Urea, Electrolytes, Bicarbonates
- Urine or Blood analysis for ketones
- ECG
- Infection screen
- Full blood count
- Blood and Urine culture
- C-reactive protein
- Chest X-ray
Treatment for Diabetic Ketoacidosis
- Insulin
- A fixed rate IV infusion of 0.1U/kg body weight/hr is recommended
- If IV not possible soluble insulin can be given by intramuscular injection with loading dose of 10-20 U, followed by 5 U hourly
- Alternatively fast acting insulin analogue can be given hourly by subcutaneous injection with initial dose of 0.3 U/kg body weight, followed by 0.1 U/kg hourly
- Fluid Replacement
- Rapid fluid replacement for first few hours is recommennded for adults
- Caution is recommended in children and adolescent due to chances of developing cerebral oedema
- Potassium
- Careful monitoring of potassium is essential to prevent hyperkalaemia or hypokalaemia
- Potassium replacement usually not recommended in initial treatment because pre-renal failure maybe present secondary to dehydration
- Cardiac rhythm should be monitored in severe DKA due to risk of electrolyte induced cardiac arrhythmia
- Bicarbonate: Adequate fluid and insulin replacement should resolve acidosis