Diabetic ketoacidosis
Diabetic ketoacidosis (DKA) is an acute, life-threatening complication that usually occurs in new-onset and established type 1 diabetic patients due to a state of severe insulin deficiency. This condition is characterized by hyperglycemia, ketoacidosis, and ketonuria.
Epidemiology
Diabetic ketoacidosis is usually associated with type 1 diabetes mellitus but is not uncommon in some patients with type 2 diabetes mellitus. Approximately 30% of children and adolescents with a new diagnosis of type 1 diabetes present with diabetic ketoacidosis at their first presentation .
Clinical presentation
Polydipsia and polyuria are the most common early symptoms of diabetic ketoacidosis, other signs and symptoms include :
- nausea, vomiting, abdominal pain, anorexia, rapid weight loss
- dehydration (e.g. manifesting as postural hypotension, tachycardia, xerostomia)
- Kussmaul respiration (deep and labored breathing)
- ketosis breath often described as 'fruity'
- drowsiness, lethargy, confusion, stupor, seizures
Pathology
Diabetic ketoacidosis usually occurs in type 1 diabetic patients and is commonly precipitated by inadequate or discontinuation of insulin therapy, or infection (often urinary tract infection or pneumonia). Other precipitating factors include alcohol intoxication, glucocorticoids, ischemia or infarction, or an intra-abdominal process (e.g. pancreatitis or cholecystitis). These lead to insulin deficiency due to increased counter-regulatory hormones. This triggers unrestricted hepatic glucose production causing hyperglycemia, and can also trigger lipolysis and subsequent ketogenesis. Both hyperglycemia and hyperketonaemia cause osmotic diuresis, dehydration and diabetic ketoacidosis .
Radiographic features
The role of imaging is to detect possible causes and complications.
Plain radiograph
Chest radiography helps rule out pulmonary infections, such as pneumonia.
CT/MRI
Cerebral edema occurs in about 0.5-1% of pediatric diabetic ketoacidosis. It is also the most common neuroimaging finding associated with pediatric diabetic ketoacidosis . Neuroimaging (CT or MRI) may demonstrate effacement of the sulci and basilar cisternal spaces, compression and decreased the size of the cerebral ventricles, and reduction of grey and white matter differentiation .
Other possible neuroimaging findings include focal infarction, ischemic and hemorrhagic stroke, extrapontine myelinolysis, and sinovenous thrombosis .
Treatment and prognosis
DKA is a medical emergency and institutions will often have set protocols regarding urgent management. However, the principles of treatment should be the same as :
- correction of volume depletion with the administration of intravenous fluids
- correction of hyperglycemia with a short-acting insulin infusion
- potassium replacement and correction of other electrolytes
- search for the underlying cause
The overall mortality rate for diabetic ketoacidosis is 2.5-5% in developed countries.
Differential diagnosis
