Sick-day rules are taught at diagnosis, remembered for a year, and then reconstructed badly at three in the morning by someone vomiting. The failure is not knowledge; it is retrieval under stress, and the fix is a piece of paper or a note on the phone that does not require thinking.
The content is short. Never stop the basal insulin, whatever the oral intake. Test glucose every two to four hours and ketones every four hours while unwell. Keep drinking - roughly a cup of fluid an hour. Give correction doses by the agreed scale, and know the specific numbers that mean stop and seek help: ketones above 3.0 mmol/L, persistent vomiting, glucose that will not come down after two corrections, or breathlessness.
For anyone on an SGLT2 inhibitor, add one line above all of it: pause the SGLT2 inhibitor at the onset of acute illness, reduced oral intake, or before surgery, and remember that ketoacidosis can occur with a normal or near-normal glucose. Write the plan with the patient rather than handing it over, put a copy where a family member will find it, and re-read it aloud at annual review. The patients who arrive in ketoacidosis have almost always had the rules explained to them.
- Write the sick-day plan down and put it where the patient and a family member will find it at night.
- Never stop basal insulin during illness, whatever the oral intake.
- Specify the numbers that trigger help: ketones above 3.0 mmol/L, persistent vomiting, breathlessness, or glucose unresponsive to two corrections.
- For anyone on an SGLT2 inhibitor, pause it at the onset of acute illness and before surgery - and warn about euglycaemic ketoacidosis.
- Re-read the plan aloud at annual review; treat it as a prescription that needs renewing.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for diabetes & endocrinology, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free