Diabetic Ketoacidosis - Sick Day Rules and Outpatient Prevention

Key Points

• Never stop basal insulin in type 1 diabetes solely because the patient is not eating.
• Check glucose more frequently during illness and test ketones when sick or hyperglycemic.
• ADA patient guidance recommends ketone testing every four to six hours during illness.
• Pump failure can cause rapid DKA because there is no long-acting insulin depot.
• SGLT2-associated DKA can occur with only modest hyperglycemia.
• Persistent ketones, vomiting, dehydration, or abnormal breathing require urgent escalation.
• DKA prevention requires reliable insulin and supply access, not education alone.
• Every DKA admission should end with a specific prevention plan for the identified trigger.

Algorithm

1. Identify the precipitating cause of the prior DKA episode.
2. Confirm access to basal/prandial insulin, ketone testing, glucose monitoring, and pump supplies.
3. Provide a written sick-day and correction-insulin plan.
4. Continue basal insulin and increase glucose/ketone monitoring during illness.
5. Use hydration and carbohydrate-containing fluids as directed to permit safe insulin treatment.
6. Troubleshoot pump delivery immediately when glucose and ketones rise unexpectedly.
7. Seek urgent care for worsening ketones, vomiting, dehydration, respiratory symptoms, or confusion.
8. Arrange early diabetes follow-up and address social or mental-health barriers.

Clinical Synopsis & Reasoning

DKA develops when effective insulin is insufficient and counter-regulatory stress promotes lipolysis and ketone production. Common triggers include missed insulin, pump or infusion-set failure, infection, new-onset diabetes, myocardial infarction, stroke, pregnancy, eating disorders, and medications that increase risk. SGLT2 inhibitors can produce euglycemic DKA in which glucose is only modestly elevated, so patients taking these drugs need specific sick-day education and clinicians should not exclude DKA because glucose is below classic levels.

Prevention begins with understanding why a previous episode occurred. Ask about cost, insurance, prescription access, unstable housing, health literacy, depression, substance use, fear of weight gain, injection burden, pump supplies, and inability to reach a clinician. Repeated education without fixing insulin access is not an effective prevention strategy. Before discharge after DKA, verify that basal and prandial insulin are actually available and that the patient can demonstrate dosing and monitoring.

During illness, glucose should be checked more frequently and ketones checked when glucose is elevated or the patient feels unwell. The ADA advises ketone testing every four to six hours when sick. Blood beta-hydroxybutyrate testing is generally more responsive than urine ketones when available. Patients need individualized instructions for correction insulin, hydration, carbohydrate-containing fluids when unable to eat, and what to do when vomiting prevents normal intake. Type 1 diabetes requires continued basal insulin even if food intake falls; withholding basal insulin can rapidly precipitate ketosis.

Treatment Strategy & Disposition

Provide a written sick-day plan with specific glucose and ketone thresholds and phone numbers. Encourage frequent sugar-free fluid when glucose is high and carbohydrate-containing fluid when needed to permit insulin dosing during poor intake. Continue prescribed basal insulin and use correction insulin according to the diabetes plan. Pump users should know how to troubleshoot an infusion set, check for ketones, give insulin by injection if pump delivery is uncertain, and replace the set promptly.

Escalate care for persistent moderate or large ketones, rising blood beta-hydroxybutyrate despite correction insulin, repeated vomiting, inability to keep fluids down, abdominal pain, rapid or deep breathing, confusion, severe weakness, or signs of dehydration. Pregnancy lowers the threshold for urgent evaluation because DKA can develop faster and at lower glucose concentrations. Patients using SGLT2 inhibitors should have a drug-specific sick-day plan, including when to hold the medication during acute illness, fasting, or procedures according to current diabetes guidance.

At every post-DKA visit, review insulin technique, injection-site issues, CGM or meter data, ketone supplies, pump function, and the precipitating social or medical factor. Consider diabetes education, pharmacy assistance, social work, mental-health care, and endocrinology support. Recurrent DKA is a systems problem as often as it is an adherence problem, and prevention requires reliable access and rapid communication.

Epidemiology / Risk Factors

• DKA occurs most often in type 1 diabetes but can occur in type 2 diabetes and other forms.
• Recurrent episodes cluster in patients with access barriers, psychosocial stress, and prior DKA.
• Pump interruption can produce ketosis quickly.
• SGLT2 inhibitors have introduced an important euglycemic DKA phenotype.

Investigations

Call or Seek Care When

Pharmacology

Prognosis / Complications

• DKA is highly treatable, but recurrence carries cumulative morbidity and cost.
• Reliable insulin access and structured education reduce preventable episodes.
• Recurrent DKA is associated with higher future risk and should trigger intensive follow-up.
• Prognosis is excellent when patients recognize ketosis early and obtain timely treatment.

Patient Education / Counseling

• Keep basal insulin available and know exactly what to do when you cannot eat.
• Check ketones during illness or persistent hyperglycemia according to your plan.
• Drink fluids regularly and use carbohydrate-containing liquids when needed for insulin dosing.
• Know how to give backup injected insulin if a pump fails.
• Seek emergency care for repeated vomiting, deep breathing, confusion, or inability to keep fluids down.
• Keep diabetes-team contact information and a written sick-day plan accessible.

Notes

A prevention plan is only useful if it works at 2 AM during vomiting or a pump failure. Give concrete doses or individualized instructions, ketone thresholds, backup delivery options, and contact numbers. Confirm that the patient has insulin in hand before discharge. When recurrent DKA reflects cost or unstable housing, solving access is part of medical treatment.

References

1. ADA/EASD/JBDS/AACE/DTS: 2024 Consensus Report on Hyperglycemic Crises in Adults With Diabetes — Link
2. American Diabetes Association: Diabetes and Planning for Sick Days — Link
3. American Diabetes Association: DKA Signs, Symptoms, Treatment and Prevention — Link