A 31-year-old man with diabetes comes to the emergency department with abdominal discomfort, nausea, and vomiting. He has not felt well for the past 2 days and has had intractable vomiting. The patient stopped taking his regular dose of insulin as he was unable to "hold anything down." His initial laboratory results are positive for serum ketones and show blood glucose of 360 mg/dL. In the emergency department, he is started on intravenous normal saline with potassium and a continuous insulin infusion. Five hours after his admission to the intensive care unit, he feels better. Laboratory results are as follows:

Which of the following is the best next step in management of this patient?

Question

A 31-year-old man with diabetes comes to the emergency department with abdominal discomfort, nausea, and vomiting.  He has not felt well for the past 2 days and has had intractable vomiting.  The patient stopped taking his regular dose of insulin as he was unable to "hold anything down."  His initial laboratory results are positive for serum ketones and show blood glucose of 360 mg/dL.  In the emergency department, he is started on intravenous normal saline with potassium and a continuous insulin infusion.  Five hours after his admission to the intensive care unit, he feels better.  Laboratory results are as follows:
 
Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: This patient has diabetic ketoacidosis (DKA), characterized by hyperglycemia with metabolic acidosis and positive serum ketones. His DKA was likely precipitated by not taking the appropriate dosage of insulin and was exacerbated by stress from his concurrent illness. Initial management of DKA includes aggressive intravenous (IV) fluid support with normal saline and continuous IV insulin. Because insulin promotes potassium entry into the cells, patients may rapidly develop hypokalemia. Potassium should be monitored closely and added to the IV fluids if serum potassium levels are <5.2 mEq/L. The patient's laboratory results after initiation of insulin therapy show that his bicarbonate level is low and anion gap (serum Na - [serum Cl + serum bicarbonate]) is 27 mEq/L (normal 7-13 mEq/L), indicating ongoing ketoacidosis. IV insulin should be continued until the anion gap has normalized (Choices A and E). (Choices B and C) In patients with a persistently elevated anion gap but blood glucose <200 mg/dL, the insulin dose should be halved and the patient should receive IV fluids with 5% dextrose to prevent hypoglycemia. The sodium concentration of IV fluids is determined by the corrected serum sodium (measured sodium + 0.016 [measured glucose - 100]). 0.9% normal saline should be continued for corrected sodium <135 mEq/L, but half (0.45%) normal saline should be given for corrected sodium >135 mEq/L. Educational objective: The initial management of diabetic ketoacidosis consists of intravenous (IV) insulin, aggressive fluid support, and potassium supplementation. If serum glucose falls to <200 mg/dL but the patient still has an elevated anion gap, the rate of insulin infusion should be halved and dextrose added to the IV fluids to prevent hypoglycemia. References: Diabetic ketoacidosis. (http://www.ncbi.nlm.nih.gov/pubmed/15887449)

A 31-Year-Old Man with Diabetes Comes to the Emergency Department