Caring for the hospitalised patient with diabetes: glucose checks, meals, fasting for procedures and illness
- Safe practice
In hospital the nurse times glucose checks and insulin to the meals, plans fasting for procedures and watches for both highs and lows.
What it is
Illness, fasting, steroids, tube feeds and changes to the usual medicines all shift blood glucose in hospital. Nursing care keeps checks, meals and insulin in step. Point-of-care glucose is checked before meals when the patient eats and every 4–6 hours when they do not. A plan with basal insulin, plus prandial and correction insulin when the patient eats, is preferred over correction-only («sliding scale») insulin. Fasting for a procedure, an interrupted feed or a lower steroid dose changes the need for insulin, so the nurse reports these changes before the next dose. The glucose targets, the insulin orders and the hypoglycaemia protocol are set by the institution.
What it requires
- An HbA1c is requested on admission if there is none from the last three months.
- The institution sets the glucose targets and uses validated order sets for ward, emergency and ICU patients.
- An unexpected result, especially a low one without symptoms, is repeated and, if similar, confirmed with a laboratory sample.
- A patient's own pump or continuous monitor is kept only with an order, a daily team agreement, pharmacy review and nursing supervision; dosing decisions use a point-of-care check.
How it is applied (and why)
- Ask on admission about the type of diabetes, home medicines, devices and recent lows: this is the baseline for the plan.
- Check glucose before each meal, or every 4–6 hours if the patient does not eat: insulin decisions rest on a current value.
- Give the prandial insulin when the tray arrives and the patient can eat: a delayed or missed meal after insulin causes hypoglycaemia.
- Report poor intake, vomiting or a stopped tube feed before the next dose: the order may need to change.
- Before a procedure, confirm with the team which medicines are held and check glucose every 2–4 hours while fasting.
- If an enteral or parenteral feed stops suddenly, tell the doctor at once: a dextrose infusion may be needed to prevent a low.
- With steroid therapy, watch afternoon and evening values and report every dose change: the insulin need follows the steroid.
- Treat any low with the hypoglycaemia protocol, record it and report it at handoff: episodes are tracked and the plan is reviewed.
- Start teaching early (medicines, monitoring, lows, sick days, supplies): it prepares a safe discharge.
In nursing practice
- Common causes of lows in hospital: reduced intake, vomiting, interrupted feeds, a lower steroid dose and late glucose checks.
- Meals served on demand close together can lead to insulin «stacking»: tell the team when the patient eats outside the usual times.
- Continuous feeding works like a long meal: an interruption leaves the insulin acting with no glucose coming in.
- Before discharge: medicine reconciliation, a follow-up appointment, and supplies and teaching for glucose monitoring.
Common mistakes
- Starting insulin with no glucose checked, or giving prandial insulin before the patient can eat.
- Giving the usual dose to a fasting patient without confirming the order for that day.
- Forgetting basal insulin in type 1 diabetes because the patient is fasting.
- Relying on a verbal glucose report as the only basis for an insulin dose.
Test yourself
Think of the answer, then tap the question to see it.
How often is glucose checked in a hospitalised patient with diabetes who is eating, and in one who is not?
Before meals when the patient eats; every 4–6 hours when the patient is not eating, and every 2–4 hours while fasting for a procedure.
Why is correction-only insulin («sliding scale») discouraged?
Because it treats a high value after it happens instead of covering the basal need and meals. A plan with basal insulin, plus prandial and correction insulin with meals, is preferred.
A patient with type 1 diabetes is fasting before surgery. Is basal insulin stopped?
No. A person with type 1 diabetes always needs basal insulin, even when not eating; the team adjusts the order for the fasting day.
What should the nurse do if a continuous tube feed stops suddenly in a patient on insulin?
Tell the doctor at once and check glucose: the insulin keeps acting with no glucose coming in, and a dextrose infusion may be needed to prevent hypoglycaemia.
Elsewhere in DurgiPedia
Connections
In Pharmacology1
Educational content for students; it does not replace your institution's protocols, supervised clinical training or a prescriber's order. Dose-calculation examples use made-up numbers: they are educational, not a clinical order.
Sources: 16. Diabetes Care in the Hospital: Standards of Care in Diabetes—2025 (American Diabetes Association Professional Practice Committee, Diabetes Care (PMC), 2025); Nursing Pharmacology, 9.4: Antidiabetics (Open RN, Wisconsin Technical College System (CC BY 4.0), LibreTexts, 2023); Guía de práctica clínica para el diagnóstico, tratamiento y seguimiento de la diabetes mellitus tipo II en la población mayor de 18 años (GPC-2015-51), versión para pacientes (Ministerio de Salud y Protección Social de Colombia, 2015).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.