Sick-Day Management, Surgery, Travel & Emergency Preparedness
Key Takeaways
- During illness, basal insulin must never be stopped -- the liver keeps releasing glucose regardless of food intake, so insulin needs typically increase, not decrease.
- People with type 1 diabetes should check ketones any time illness occurs, and anyone should check ketones when blood glucose exceeds 240 mg/dL, rechecking every 4-6 hours.
- SGLT2 inhibitors should be held 3-4 days before surgery due to the risk of euglycemic DKA; metformin is held the day of surgery and other oral agents the morning of surgery.
- ADA recommends a perioperative blood glucose target of 100-180 mg/dL within 4 hours of surgery.
- Insulin should never be packed in checked airline luggage, since unpressurized cargo holds can freeze it and permanently destroy its potency.
Sick-Day Management
Illness — even a routine cold, flu, or stomach virus — triggers counter-regulatory hormones (cortisol, glucagon, catecholamines, growth hormone) that raise blood glucose and increase insulin resistance, independent of appetite or food intake. In type 1 diabetes this stress response can produce diabetic ketoacidosis (DKA) within hours if insulin is reduced. The single most dangerous sick-day error is withholding basal (background) insulin because "I'm not eating" — the liver keeps releasing glucose through gluconeogenesis and glycogenolysis whether or not food is consumed, so basal insulin needs typically stay the same or increase during illness, and should never be stopped outright.
The Core Sick-Day Rules
Every person who takes insulin — and every CDCES teaching them — should have a written sick-day plan built around five actions:
- Never stop insulin. Continue basal/background insulin (or basal pump rate) even without appetite; total daily dose often needs to increase, not decrease.
- Check blood glucose every 2–4 hours, including overnight, for the duration of the illness.
- Check ketones (blood or urine) any time illness occurs in type 1 diabetes, regardless of glucose level, and in anyone whose glucose exceeds 240 mg/dL; recheck every 4–6 hours until ketones clear.
- Stay hydrated — drink at least 8 ounces (about 1 cup) of sugar-free fluid every hour while awake; switch to carbohydrate-containing fluids (juice, regular soda, broth with sugar) if glucose is normal or low and solid food cannot be tolerated.
- Give correction doses of rapid-acting insulin per the individualized sick-day plan when glucose or ketones are elevated.
When to Seek Emergency Care
| Warning Sign | Why It Matters |
|---|---|
| Moderate–large ketones | Signals developing ketoacidosis; call the provider or go to the emergency department |
| Vomiting/diarrhea >6 hours, fluids not tolerated | Dehydration and DKA risk rise quickly |
| Glucose persistently >300 mg/dL despite correction doses | Insulin needs likely underestimated; contact the provider |
| Fruity breath, rapid/deep (Kussmaul) breathing, abdominal pain, confusion | Classic DKA warning signs — emergency care immediately |
Surgery and Procedures
Perioperative glycemic management balances the risks of hyperglycemia (impaired wound healing, infection) against hypoglycemia during required fasting. ADA recommends a perioperative blood glucose goal of 100–180 mg/dL within 4 hours of surgery. Medication adjustments before a scheduled procedure follow a consistent, testable pattern:
| Medication | Perioperative Instruction | Rationale |
|---|---|---|
| Metformin | Hold on the day of surgery | Lactic-acidosis risk rises with contrast dye or reduced renal perfusion under anesthesia |
| Other oral agents (sulfonylureas, DPP-4 inhibitors, TZDs) | Hold the morning of the procedure | Sulfonylureas especially risk hypoglycemia once fasting begins |
| SGLT2 inhibitors | Hold 3–4 days before surgery | Risk of euglycemic DKA — ketoacidosis with a near-normal glucose that can be missed if glucose alone is monitored |
| Insulin | Individualized — basal usually continued at a reduced dose (commonly 75–80% of usual); mealtime/rapid-acting doses held while NPO | Prevents both starvation ketosis and hypoglycemia during fasting |
Correction-dose insulin is used throughout the perioperative period to maintain the 100–180 mg/dL target, and glucose is monitored frequently until the person resumes normal oral intake and their usual regimen.
Travel
Traveling with diabetes takes deliberate planning across three domains:
- Time zones. Basal-bolus and pump regimens adapt more easily to time-zone shifts than fixed-dose regimens. Plan insulin-timing adjustments with the care team before trips crossing multiple zones, and never skip a basal dose to "catch up" — doing so risks both hyperglycemia and, later, stacking of doses.
- Insulin storage. Unopened insulin belongs in the refrigerator (36–46°F/2–8°C). In-use pens and vials are stable at room temperature for their labeled duration, but must avoid freezing and temperatures above 86°F (30°C). Never pack insulin in checked luggage — unpressurized, unheated cargo holds can freeze insulin and permanently destroy its potency.
- Supplies. Carry at least twice the anticipated supply of insulin, test strips, pump/CGM consumables, and oral medications in carry-on luggage, not checked bags; split supplies between travel companions or multiple bags when possible. Carry a prescription list or provider letter — diabetes supplies and liquids are permitted through security screening in excess of standard limits once declared to screening staff.
Emergency and Disaster Preparedness
A diabetes emergency/disaster kit should be reviewed and refreshed on a regular schedule and should include:
- At least a 1–2 week supply of insulin, oral medications, and pump/CGM consumables (or a documented backup injection plan for anyone who is device-dependent)
- Glucagon (for insulin users), a glucose and ketone meter with extra strips, and fast-acting glucose sources
- Copies of prescriptions, the personal diabetes care/sick-day plan, and a list of current medications
- A medical ID and an emergency contact list
- An insulated cooling method (a cooling pouch or ice packs) to protect insulin during a power outage or evacuation
Anyone using an insulin pump or CGM should always maintain a working backup plan for manual injections and fingerstick glucose monitoring in case the device fails, loses power, or cannot be resupplied during an emergency.
According to sick-day guidance, when should a person with type 1 diabetes check for ketones during an illness?
Which medication class should be discontinued 3-4 days before a scheduled surgery because of the risk of euglycemic diabetic ketoacidosis?