Points to Ponder for NEET-PG, FMGE & NEXT
- DKA is a serious complication of diabetes caused by insulin deficiency and increased ketogenesis.
- Common triggers include insulin non-adherence and increased insulin needs due to stress or illness.
- Labs show hyperglycemia, metabolic acidosis, elevated ketones, and potential electrolyte abnormalities.
- Treatment involves IV fluids, insulin therapy, and cautious potassium replacement.
Definition
- DKA is a life-threatening complication of diabetes mellitus due to a relative or absolute insulin deficiency, characterized by hyperglycemia, metabolic acidosis, and elevated ketone bodies.
Pathophysiology:
- Insulin deficiency: Absolute or relative lack of insulin leads to:
- Insufficient insulin leads to increased glucagon secretion, promoting gluconeogenesis and glycogenolysis (breakdown of stored glucose) in the liver, resulting in hyperglycemia.
- Increased lipolysis: Free fatty acid (FFA) mobilization from adipose tissue increases due to lack of insulin’s inhibitory effect.
- Ketogenesis: Elevated FFAs in the liver undergo excessive breakdown, leading to the production of ketone bodies (acetoacetate, beta-hydroxybutyrate, and acetone).
- Metabolic Acidosis: Ketone bodies are strong acids that overwhelm the body’s buffering capacity, leading to metabolic acidosis.
Triggers:
- Insulin non-compliance: Most common cause, especially in type 1 diabetes.
- Increased insulin requirements: Stressful conditions like infections, injuries, surgery, or emotional distress can increase insulin needs.
- Other: Certain medications (e.g., corticosteroids), undiagnosed or poorly controlled diabetes.
Cardinal features:
- Dehydration: Due to osmotic diuresis caused by hyperglycemia.
- Hyperglycemia: Elevated blood sugar levels.
- Metabolic acidosis: Low bicarbonate (HCO3-) and increased anion gap.
- Ketonemia and ketonuria: Presence of ketones in the blood and urine.
Clinical Features:
- Dehydration: Due to osmotic diuresis caused by hyperglycemia.
- Fruity breath odor: Caused by exhaled acetone.
- Kussmaul respirations: Deep, rapid breathing to compensate for metabolic acidosis.
- Nausea, vomiting, abdominal pain: Due to gastroparesis and ketosis.
- Altered mental status: Confusion, delirium, or coma can occur in severe cases.
Laboratory Findings:
- Hyperglycemia: Blood sugar levels significantly elevated.
- Metabolic acidosis: Low pH, low bicarbonate, and elevated anion gap.
- Elevated ketones: Measured in blood and urine.
- Electrolyte abnormalities:
- Hyperkalemia (high potassium): Initially due to release from cells, but can mask underlying total body potassium depletion.
- Hyponatremia (low sodium): Due to fluid losses.
Complications:
- Cerebral edema: Life-threatening swelling of the brain.
- Mucormycosis: Fungal infection, particularly in patients with severe DKA and ketoacidosis.
- Cardiac arrhythmias: Irregular heartbeats.
- Heart failure: Due to dehydration and electrolyte imbalances.
- Acute respiratory distress syndrome (ARDS): Fluid buildup in the lungs.
- Electrolyte imbalances: Can worsen with inappropriate management.
Treatment:
- Immediate resuscitation:
- Intravenous (IV) fluids: To correct dehydration and improve circulation.
- Insulin therapy: IV insulin to suppress glucagon secretion and promote glucose uptake into cells.
- Potassium replacement: Cautious administration to address intracellular potassium depletion while avoiding hyperkalemia.
- Monitoring and management:
- Frequent monitoring of blood sugar, electrolytes, and ketones.
- Correction of underlying cause (e.g., infection treatment).
- Gradual transition to subcutaneous insulin once stable.
