From the Guidelines
Essential laboratory tests for managing Diabetic Ketoacidosis (DKA) include blood glucose, serum ketones (beta-hydroxybutyrate), arterial blood gases, serum electrolytes (particularly potassium, sodium, chloride, and bicarbonate), blood urea nitrogen (BUN), creatinine, complete blood count, and urinalysis. These tests are crucial for assessing the severity of DKA, guiding treatment, and monitoring the patient's response to therapy 1.
Key Laboratory Tests:
- Blood glucose monitoring should be performed hourly until stable
- Electrolytes should be checked every 2-4 hours initially
- Serum ketones help track ketoacidosis resolution
- Arterial blood gases assess the severity of acidosis with pH and bicarbonate levels
- Potassium monitoring is critical as levels can drop precipitously during insulin therapy despite initial elevations
Additional Tests to Consider:
- Cardiac enzymes in older patients
- HbA1c to distinguish between new-onset and poorly controlled diabetes
- Cultures if infection is suspected as a precipitating factor Point-of-care testing for glucose and ketones allows for rapid treatment adjustments, and ongoing monitoring of these parameters guides fluid resuscitation, insulin therapy, and electrolyte replacement, which form the cornerstones of DKA management 1. According to the most recent guidelines, the use of bicarbonate in patients with DKA is generally not recommended as it has been shown to make no difference in the resolution of acidosis or time to discharge 1. In critically ill and mentally obtunded patients with DKA, continuous intravenous insulin is the standard of care, but there is no significant difference in outcomes for intravenous regular insulin versus subcutaneous rapid-acting analogs when combined with aggressive fluid management for treating mild or moderate DKA 1.
From the Research
Laboratory Tests in Diabetic Ketoacidosis (DKA)
The following laboratory tests are essential in managing DKA:
- Measurement of A1C, blood urea nitrogen, creatinine, serum glucose, electrolytes, pH, and serum ketones 2, 3
- Complete blood count 2, 3
- Urinalysis 2, 3
- Electrocardiography 2, 3
- Calculation of anion gap and osmolar gap 2
- Amylase, lipase, hepatic transaminase levels, troponin, creatine kinase, blood and urine cultures, and chest radiography may be considered in certain cases 3
Diagnosis of DKA
DKA can be diagnosed by the presence of hyperglycemia, metabolic acidosis, and elevated serum ketone levels 2, 3, 4, 5. The diagnosis can be made by measuring blood glucose and ketones using a meter, and venous blood pH on a blood gas analyzer 4.
Serum Ketone Body Measurement
Serum ketone body levels can be useful in the diagnosis of DKA, with optimal cut-off values determined at 6.3 mmol/l of beta-hydroxybutyrate, 1.4 mmol/l of acetoacetate, and 8.0 mmol/l of total ketone body 5.
Differentiation from Other Conditions
Laboratory tests can help differentiate DKA from other metabolic syndromes, such as hyperosmolar hyperglycemic state, gastroenteritis, and starvation ketosis 2, 3. Euglycemic DKA, a rare complication of diabetes, can be diagnosed by the presence of metabolic acidosis, ketosis, and blood glucose levels < 250 mg/dL 6.