A 22-year-old man with type 1 diabetes mellitus is brought to the emergency department due to lethargy, nausea, vomiting, and diffuse abdominal pain for the past 24 hours. He recently had a viral upper respiratory infection. Temperature is 37.2°C (99.0°F), blood pressure is 90/60 mmHg, pulse is 125/min, and respirations are 28/min and deep. Mucous membranes are dry and capillary refill is prolonged. Laboratory studies show:
| Laboratory test | Result |
|---|---|
| Serum glucose | 650 mg/dL |
| Serum sodium | 132 mEq/L |
| Serum potassium | 3.1 mEq/L |
| Serum bicarbonate | 10 mEq/L |
| Serum chloride | 98 mEq/L |
| Arterial blood pH | 7.15 |
Urine ketones are strongly positive.
Arrange the following management steps in the correct chronological order of administration for this patient according to standard diabetic ketoacidosis (DKA) protocols.
- 1Administer a rapid intravenous bolus of 0.9% normal saline
- 2Administer intravenous potassium chloride
- 3Initiate a continuous intravenous infusion of regular insulin
- 4Add 5% dextrose to the intravenous fluids
Answer
The correct sequence is: 1) Administer rapid IV 0.9% normal saline, 2) Administer IV potassium chloride, 3) Initiate continuous IV regular insulin, 4) Add 5% dextrose to IV fluids.
The standard sequence for DKA management requires aggressive initial fluid resuscitation with 0.9% normal saline. Following fluid initiation, potassium levels dictate the next step. If potassium is < 3.3 mEq/L, insulin must be withheld and intravenous potassium given first. Once potassium is ≥ 3.3 mEq/L, an IV insulin infusion is started to close the anion gap. Finally, when blood glucose reaches 200-250 mg/dL, dextrose is added to IV fluids to prevent hypoglycemia while insulin continues.
Step-by-Step Solution
Key Concept
Algorithm for Diabetic Ketoacidosis (DKA) management, specifically recognizing the critical threshold of serum potassium (< 3.3 mEq/L) that dictates withholding insulin until potassium is replenished.