A 36-year-old woman presents to the emergency department for evaluation and management of refractory nausea, vomiting, and abdominal pain. Symptoms have persisted for 2 days, and the patient has felt somewhat short of breath and light-headed when standing for the past 12 hours. She was diagnosed with gestational diabetes mellitus 3 years ago and then type 2 diabetes when hyperglycemia persisted after delivery. The patient's only medication is metformin. Examination is notable for resting tachycardia, mild tachypnea, dry mucous membranes, and modest, diffuse pain on palpation of the abdomen. Capillary blood glucose (CBG) is >500 mg/dL.
Initial electrolyte panel revealed sodium 132 mEq/L, potassium 4.6 mEq/L, chloride 92 mEq/L, bicarbonate 12 mEq/L, blood urea nitrogen (BUN) 20 mg/dL, creatinine (Cr) 0.7 mg/dL, and glucose 520 mg/dL. Anion gap was computed to be 28. Arterial blood gas was notable for pH 7.21, pCO2 34 mm Hg, pO2 80 mm Hg, and calculated bicarbonate 14 mEq/L. Urinalysis was remarkable for large glucose and ketones, but nitrites and leukocyte esterase were undetectable. Complete blood count (CBC) showed modest leukocytosis and elevation of neutrophil count. Markers of liver function, amylase, lipase, EKG, and chest plain films were unremarkable.
1. How is diabetic ketoacidosis (DKA) diagnosed?
2. How should DKA patients be evaluated?
3. What are the appropriate steps in DKA management?
DKA is diagnosed by the simultaneous occurrence of hyperglycemia, ketonemia and ketonuria, and anion gap acidemia. The differential diagnosis of ketosis is presented in Table 21-1, and American Diabetes Association (ADA) diagnostic criteria are presented in Table 21-2.
Metabolic confirmation of the diagnosis includes timely measurements of glucose, urine ketones, and electrolytes to allow computation of an anion gap (Na–Cl–HCO3). Patients should also be evaluated for potential secondary causes of DKA. Pneumonia and urinary tract infections are the most common precipitating causes.
Successful management of DKA requires parenteral insulin, hydration, and potassium repletion. ADA recommendations are summarized in Table 21-4.
Table 21-1. Etiologies of Ketosis |Favorite Table|Download (.pdf)
Table 21-1. Etiologies of Ketosis
|Fasting (infancy, pregnancy)||N, D|
|Prolonged exercise||N, occ D|
|Ketogenic diet||N, occ D|
|GH insufficiency (children)||D|
|Isopropyl alcohol poisoning||N|
Table 21-2. American Diabetes Association (ADA) Diagnostic Criteria for DKA |Favorite Table|Download (.pdf)
Table 21-2. American Diabetes Association (ADA) Diagnostic Criteria for DKA