NU650 Unit 8 DKA Protocol With Low Potassium Example

Insulin Waits for Potassium: A Diabetic Ketoacidosis Protocol for a 34-Year-Old Whose Pump Failed During a Stomach Virus

[Student Name]

Purdue University Global

NU650: AGACNP Introduction to Acute Care Management I

Unit 8 Diabetic Ketoacidosis Protocol

[Instructor Name]

[Date]

The patient is composite; values, rates and times are bracketed, and the protocol follows the hospital's order set where the consensus leaves a choice.

Opening Panel

Ms. [R.] is a [34]-year-old woman, [64] kg, with type 1 diabetes for [19] years managed with an insulin pump. [Two] days of vomiting and diarrhea from a household stomach virus led her to eat little, and she did not notice that her infusion set had kinked overnight. She arrives alert, breathing deeply, with a pulse of [118] and a blood pressure of [104/66].

1. Glucose [486] mg/dL.

2. Venous pH [7.12]; bicarbonate [9] mEq/L; anion gap [26].

3. Beta-hydroxybutyrate [6.2] mmol/L.

4. Potassium [3.2] mEq/L.

5. Sodium [131] mEq/L, corrected for glucose to about [137] mEq/L.

6. Creatinine [1.4] mg/dL; her baseline is [0.8].

7. ECG: sinus tachycardia, no U waves or peaked T waves.

Diagnosis

The 2024 consensus report sets three criteria: glucose of at least 200 mg/dL or known diabetes, ketonemia with a beta-hydroxybutyrate of at least 3.0 mmol/L, and acidosis with a pH below 7.3 or a bicarbonate below 18 mEq/L (Umpierrez et al., 2024). She meets all three. Allowing known diabetes to stand in for the glucose criterion matters in practice, because it catches patients whose glucose is near normal, such as those taking an SGLT2 inhibitor. Her bicarbonate of [9] and pH of [7.12] place her in the severe range, and she will be managed in the step-down unit.

Order of Steps

Safety sets the sequence: fluids restore perfusion and begin to lower glucose before any insulin runs; potassium comes before insulin because insulin moves potassium into cells, and starting it at [3.2] could drop her level into the range where arrhythmia occurs. The most dangerous order in this protocol is the one that feels most urgent, and that is why insulin is written to wait.

Timeline

Hour 0. Disconnect the pump and remove the infusion set. Two intravenous lines. Balanced crystalloid [1,000] mL over the first hour. A subgroup analysis of two pragmatic trials found faster resolution of ketoacidosis with balanced crystalloids than with saline, a median of 13.0 against 16.9 hours (Self et al., 2020), and the hospital order set uses Ringer lactate unless there is a reason not to. Potassium chloride [10] mEq per hour by peripheral line, with continuous cardiac monitoring. Point-of-care glucose and a repeat potassium at [one] hour.

Hour 1. If potassium is still below [3.5]: continue potassium at [10] mEq per hour, or [20] mEq per hour through a central line if one is placed, and recheck at hour [2]. Insulin remains on hold. Fluids at [250 to 500] mL per hour guided by blood pressure, urine output and exam.

Once potassium is at least [3.5]. Start a fixed-rate intravenous insulin infusion at 0.1 units per kg per hour, [6.4] units per hour for her weight, without a bolus. Add potassium chloride [20 to 30] mEq to each liter of fluid while potassium is between [3.5] and [5.0], to keep it between [4.0] and [5.0]. Hourly glucose; potassium and basic metabolic panel every [two] hours for [six] hours, then every [four] hours; beta-hydroxybutyrate and venous pH every [two to four] hours.

When glucose falls below [250] mg/dL. Add dextrose, [10] percent at [125] mL per hour alongside the crystalloid, and keep the insulin infusion running. Glucose improves faster than ketosis, and the insulin is still needed to stop ketone production. Target glucose [150 to 200] mg/dL while the acidosis clears; reduce the insulin rate to 0.05 units per kg per hour only if glucose falls below that range despite dextrose.

Not given. Bicarbonate, because her pH is above 7.0, the level below which the consensus considers it. Phosphate, unless the level falls below [1.0] mg/dL or she develops weakness or respiratory difficulty.

Resolution

Ketoacidosis is resolved when beta-hydroxybutyrate is below 0.6 mmol/L and the venous pH is at least 7.3 or the bicarbonate at least 18 mEq/L (Umpierrez et al., 2024). The protocol uses these numbers rather than the anion gap alone, since saline and chloride can hold the gap open or closed for reasons unrelated to ketones.

Transition

Once resolution criteria are met and she can eat, give subcutaneous basal insulin, glargine [18] units, at least [two] hours before the infusion stops, so that insulin is never absent. Stopping the infusion without overlap is a recognized cause of rebound ketoacidosis (Kitabchi et al., 2009). Rapid-acting insulin with her first meal. The pump is restarted only with the diabetes team, and not until she is eating and has a working infusion set.

Prevention Before Discharge

The event began with a pump failure during an illness, and the teaching addresses both. She will leave with injection pens and a written backup plan for any pump failure, instructions to check blood ketones when glucose is above [250] mg/dL or when she is vomiting, sick-day rules for insulin while eating little, and the number for her diabetes clinic. The discharge summary will record the cause so her endocrinologist can review her set changes and ketone monitoring.

References

Kitabchi, A. E., Umpierrez, G. E., Miles, J. M., & Fisher, J. N. (2009). Hyperglycemic crises in adult patients with diabetes. Diabetes Care, 32(7), 1335-1343. https://doi.org/10.2337/dc09-9032

Self, W. H., Evans, C. S., Jenkins, C. A., Brown, R. M., Casey, J. D., Collins, S. P., Coston, T. D., Felbinger, M., Flemmons, L. N., Hellervik, S. M., Lindsell, C. J., Liu, D., McCoin, N. S., Niswender, K. D., Slovis, C. M., Stollings, J. L., Wang, L., Rice, T. W., & Semler, M. W. (2020). Clinical effects of balanced crystalloids vs saline in adults with diabetic ketoacidosis: A subgroup analysis of cluster randomized clinical trials. JAMA Network Open, 3(11), Article e2024596. https://doi.org/10.1001/jamanetworkopen.2020.24596

Umpierrez, G. E., Davis, G. M., ElSayed, N. A., Fadini, G. P., Galindo, R. J., Hirsch, I. B., Klonoff, D. C., McCoy, R. G., Misra, S., Gabbay, R. A., Bannuru, R. R., & Dhatariya, K. K. (2024). Hyperglycemic crises in adults with diabetes: A consensus report. Diabetes Care, 47(8), 1257-1275. https://doi.org/10.2337/dci24-0032