From the Guidelines
Starvation ketoacidosis is characterized by laboratory findings that include an elevated anion gap metabolic acidosis with a serum bicarbonate concentration usually not lower than 18 mEq/l, normal or low blood glucose levels, and elevated serum ketone bodies. The condition is distinguished from diabetic ketoacidosis by the presence of normal or low blood glucose levels, often below 250 mg/dl, and a clinical history of starvation or fasting 1.
Key Laboratory Findings
- Elevated anion gap metabolic acidosis
- Serum bicarbonate concentration usually not lower than 18 mEq/l 1
- Normal or low blood glucose levels
- Elevated serum ketone bodies
- Elevated free fatty acids and glycerol due to increased lipolysis
- Normal or slightly elevated lactate levels
- Normal serum osmolality
- Electrolyte abnormalities such as hypokalemia, hypomagnesemia, and hypophosphatemia due to malnutrition
- Elevated BUN from protein catabolism and dehydration These laboratory findings occur due to the body's metabolic adaptation to prolonged fasting, where the depletion of glycogen stores leads to a reliance on ketone production from fatty acids for energy. The accumulation of ketoacids overwhelms the body's buffering capacity, resulting in metabolic acidosis 1.
From the Research
Laboratory Findings of Starvation Ketoacidosis
The laboratory findings of starvation ketoacidosis include:
- High anion gap metabolic acidosis 2, 3, 4, 5
- Elevated levels of ketone bodies, such as acetoacetate and beta-hydroxybutyrate 3, 4, 6
- Presence of ketones in the urine 6, 5
- Low bicarbonate levels 5
- Normal or low lactate levels 5
- Electrolyte imbalance, including severe electrolyte imbalance consistent with refeeding 2
Biochemical Reactions
The biochemical reactions that occur in starvation ketoacidosis are triggered by a lack of insulin and an elevated glucagon level in the blood, causing unopposed lipolysis and free fatty acid oxidation, resulting in the production of ketone bodies and eventually high anion gap metabolic acidosis 3.
Detection of Ketone Bodies
The detection of ketone bodies, particularly beta-hydroxybutyrate, is important in diagnosing starvation ketoacidosis. However, current urine dipstick technology poorly detects acetone and cannot measure beta-hydroxybutyrate 6. The use of hydrogen peroxide, alkalinization, and silver nitrate sticks may improve the detection of beta-hydroxybutyrate, but the effectiveness of these methods is limited 6.