Diabetes Sick Day Rules · Reasoning GP

1

Safety

Spot DKA, HHS & Sepsis That Need Admission Now

Done

Before giving any advice, decide whether this is a sick day to manage at home or an emergency. DKA, HHS and sepsis all need urgent hospital care.

Diabetic ketoacidosis (DKA) Excessive thirst, polyuria, dehydration, laboured (Kussmaul) breathing, abdominal pain, leg cramps, nausea/vomiting, confusion/drowsiness, pear-drop breath, ketones in blood/urine → urgent admission.

Blood ketones > 3.0 mmol/L (or +++/++++ on urine) → high risk of DKA → urgent hospital assessment. Ketones >1.5 mmol/L already warrant seeking advice.

Hyperosmolar hyperglycaemic state (HHS) Glucose persistently >30 mmol/L for days, disorientation/confusion, polyuria, thirst, dry mouth, nausea, progressive drowsiness → life-threatening, urgent admission.

Persistent vomiting / can't keep fluids down Cannot maintain hydration or carbohydrate → can't safely manage at home → urgent assessment.

Drowsiness, confusion, reduced consciousness Any altered mental state in an unwell person with diabetes → emergency.

Sepsis / source needing treatment Pneumonia, pyelonephritis, abscess, cellulitis — treat the underlying infection and consider admission per sepsis assessment (NEWS2).

ℹ️ DKA occurs in type 1 diabetes, and can occur in type 2 at times of severe illness or — rarely — in those on an SGLT2 inhibitor (euglycaemic DKA, glucose may be near-normal). Don't be falsely reassured by a normal glucose if the person is acidotic/ketotic.

Poorly-managed illness is what turns a minor infection into DKA, HHS or AKI requiring emergency admission — so the first job is always to separate the patient who can be safely advised at home from the one who needs hospital now. Euglycaemic DKA on SGLT2 inhibitors is the classic trap: the glucose can be unremarkable while the patient is dangerously ketotic and acidotic.

2

Diagnose

What Triggers Sick Day Rules — and the Four Aims

Done

People with diabetes don't get ill more often, but illness can destabilise glucose fast. Any intercurrent illness can trigger the rules — the list isn't exhaustive.

Common triggers

Common cold, influenza, diarrhoea & vomiting, urinary tract infection, chest infection, pneumonia, abscess, injury (e.g. fracture). Any infection or acute stress can raise glucose.

Aim 1 — Glucose

Manage blood glucose levels — they tend to rise during illness even without eating.

Aim 2 — Calories & fluids

Ensure adequate calorie intake and hydration with fluid replacement.

Aim 3 — Ketones

Test for, and manage, ketones if present.

Aim 4 — Escalation

Recognise when further medical attention is required (Steps 1 & 8).

The four aims are the backbone of every sick-day conversation: keep glucose controlled, keep calories and fluids going, watch ketones, and know the escalation triggers. Naming them stops sick-day advice from becoming a vague "drink fluids and rest" and turns it into a concrete, safety-netted plan.

3

Treat

The SICK Rules — Sugar, Insulin, Carbohydrate, Ketones

Done

The core of home management. The single most important message: never stop insulin.

S — Sugar

Monitor more often

Glucose can rise even if not eating. Increase glucose monitoring. Sulfonylurea and insulin doses may need increasing temporarily during illness.

I — Insulin

NEVER stop insulin key

Never stop insulin or oral diabetes meds (except SADMAN, Step 4). Doses may need increasing, especially if ketones present. Insulin users → see the insulin-adjustment pathway.

C — Carbohydrate

Keep carbs & fluids going

Maintain hydration & carb intake. Not eating / vomiting → replace meals with sugary fluids. BG high → sugar-free fluids. BG low → regular sugary fluids. Sip ≥100 mL/hour.

K — Ketones

Test & treat

T1DM: check ketones every 4–6h (every 2h if present). Give extra rapid-acting insulin if ketones present (see insulin pathway). Drink water to flush ketones.

ℹ️ Metformin and SGLT2 inhibitors are the exception to "never stop" — they may need temporary stopping if there's a risk of dehydration (SADMAN, Step 4). Insulin and sulfonylureas are not stopped.

Stopping insulin during illness — often because the person isn't eating — is the commonest avoidable precipitant of DKA. During illness the counter-regulatory stress hormones drive glucose and ketones up, so the body needs more insulin, not less, even when food intake drops. The SICK mnemonic keeps all four levers (sugar, insulin, carbohydrate, ketones) in view at once.

4

Treat

The SADMAN Rules — Drugs to Temporarily Stop

Done

Several drug classes should be temporarily paused during any acute illness that can cause dehydration, then restarted on recovery.

S — SGLT2iDapagliflozin, empagliflozin, canagliflozin, ertugliflozin. Risk of euglycaemic DKA if dehydrated → stop during acute illness.

A — ACEiRamipril, lisinopril, perindopril etc. Risk of AKI (reduced efferent vasoconstriction) → stop while dehydrated.

D — DiureticsFurosemide, bendroflumethiazide, indapamide, spironolactone. Risk of AKI from volume depletion → stop.

M — MetforminMetformin. Risk of lactic acidosis if dehydrated/AKI → stop during the acute illness.

A — ARBsLosartan, candesartan, irbesartan, valsartan. Risk of AKI → stop while dehydrated.

N — NSAIDsIbuprofen, naproxen, diclofenac. Risk of AKI (reduced afferent vasodilation) → stop; use paracetamol for symptom relief.

✅ Restart all SADMAN drugs once the person is feeling better and has been eating and drinking normally for 24–48 hours.

SADMAN drugs each become dangerous in the setting of dehydration: SGLT2 inhibitors precipitate euglycaemic DKA, metformin risks lactic acidosis, and the ACEi/ARB/diuretic/NSAID combination is the classic "triple whammy" for acute kidney injury (Think Kidneys / NICE CG169). Pausing them during illness and restarting once the patient is eating and drinking normally is a simple, high-yield safety intervention.

5

Diagnose

Monitoring — Glucose & Ketone Frequency (T1 vs T2)

Done

Type 1 diabetes

Test blood glucose AND ketones every 4–6 hours, including overnight. If glucose >11 and/or ketones present, increase to every 2 hours.

Type 2 diabetes

Test blood glucose at least 4 times a day. If BG >11 and ketones present, test BG + ketones every 2 hours (including overnight).

Ketone thresholds

Blood ketones <0.6 normal · 0.6–1.5 recheck/act · 1.5–3.0 high risk, seek advice · >3.0 urgent hospital. Urine: + to ++ ≈ 1.5–3.0; +++ to ++++ >3.0.

Target while ill

Keeping glucose roughly <11–15 and ketones clear is the practical aim; don't chase tight control during acute illness.

If no ketone meter

Use urine ketone sticks; if neither available and the person is unwell with high glucose, lower the threshold to seek advice.

More frequent testing during illness is what lets you catch a rising ketone trend before it becomes DKA. Blood ketone meters are preferred over urine sticks because they reflect the current state (urine lags), and a blood ketone >1.5 mmol/L is the practical "seek advice" trigger while >3.0 mmol/L signals likely DKA.

6

Treat

Carbohydrate & Fluid Replacement

Done

Food, insulin and fluids together prevent dehydration and serious complications. Match the fluid to the glucose.

If able to eat

Continue normal carbohydrate-containing meals where possible.

If not eating / vomiting

Replace meals with sugary fluids (e.g. non-diet cola/lemonade, fruit juice, sports drinks) or easy carbs — soup, milk, ice cream, yoghurt.

If BG is HIGH

Maintain fluids with sugar-free drinks/water to rehydrate without pushing glucose higher.

If BG is LOW

Encourage regular sugary fluids to keep glucose up and prevent hypoglycaemia.

How much

Aim to sip at least 100 mL/hour if able. Small, frequent sips are better tolerated if nauseated.

Ketones present

Drink plenty of water to maintain hydration and help flush ketones, alongside extra insulin if on insulin.

The trick patients miss is that the type of fluid depends on the glucose: sugary fluids when they can't eat or BG is low, sugar-free when BG is high — but fluids never stop. Maintaining carbohydrate also prevents starvation ketosis, which compounds illness-driven ketone production.

7

Lifestyle

Recovery — Stepping Back Down & Restarting Meds

Done

Wind dose changes back down As the illness subsides, gradually reduce any increased insulin/SU doses back to the usual regimen — adjustments are incremental.

Restart SADMAN drugs Restart metformin, SGLT2i, ACEi/ARB, diuretics and NSAIDs once eating & drinking normally for 24–48 hours.

Keep monitoring briefly Continue more frequent glucose/ketone checks until stable, then return to the usual schedule.

Resume normal diet Return to the usual eating pattern and rehydrate fully.

Review what happened If the episode was severe or the person struggled to cope, arrange GP/DSN review and refresh the sick-day plan.

Check kidney function if needed After significant dehydration/AKI risk, consider rechecking U&Es per clinical judgement before restarting all nephrotoxic drugs.

Recovery is an active phase, not an afterthought: insulin/SU doses that were pushed up must be tapered back to avoid hypoglycaemia, and the SADMAN drugs should only be restarted once the patient is reliably eating and drinking. A post-episode review is a good chance to reinforce the plan and supply a sick-day kit.

8

Refer

When to Seek Urgent Help or Admit

Done

999 / admit

Suspected DKA or HHS, reduced consciousness, severe dehydration, or blood ketones >3.0 mmol/L → emergency admission.

Seek urgent advice

Vomiting / unable to keep fluids down, unable to control glucose or ketones, blood ketones >1.5 mmol/L, or persistent high glucose despite extra insulin → contact GP / DSN / urgent care.

Persistent vomiting

Cannot maintain hydration → risk of dehydration, AKI and DKA → low threshold for assessment, especially in the frail or elderly.

Unsure about dose changes

If the person is unsure how to adjust insulin/medication → contact GP or diabetes specialist nurse for advice.

Children / pregnancy / frail elderly

Lower threshold to seek help — these groups destabilise and dehydrate faster.

No improvement / deteriorating

If not improving over the expected course of the illness, or getting worse → reassess and escalate.

Clear escalation triggers — vomiting, uncontrolled glucose/ketones, ketones >1.5, drowsiness — are what convert sick-day advice into a safe plan. The patient should leave the consultation knowing exactly which symptoms mean "phone now" and which mean "go to hospital".

9

Safety

Patient Education & the Sick-Day Kit

Done

Sick-day rules only work if the patient knows them before they're ill. Give the advice proactively and provide a written plan.

Give written sick-day rules Provide TREND-UK "What to do when you are ill" (separate T1 and T2 leaflets) and document that advice was given.

Sick-day kit at home Spare blood glucose strips, in-date blood ketone meter + strips, sugary & sugar-free fluids, paracetamol, and contact numbers.

Know the SADMAN list Patient should know which of their drugs to pause when dehydrated and to restart after 24–48h well.

Never stop insulin Reinforce the golden rule — even when not eating. Insulin users → review the insulin-adjustment pathway.

Escalation numbers GP, out-of-hours, diabetes specialist nurse, NHS 111, and when to call 999.

Review high-risk groups Recent DKA, hypoglycaemia unawareness, CKD, frailty, or on SGLT2i — proactively counsel and consider a personalised plan.

Sick-day rules are preventive medicine: the evidence and guidance (TREND-UK, Think Kidneys, NICE CG169) all stress that the advice must be given and a kit prepared before illness strikes, because a frightened, vomiting patient is in no state to learn the rules from scratch. Documenting that advice was given is also good medicolegal practice.