Sick Days, Ketoacidosis and Emergencies

Sick days and emergencies: the instinct to stop the insulin is the one that kills people

A person with type 1 diabetes gets gastroenteritis. They are vomiting and cannot eat. The worker on shift reasons, sensibly, that insulin is for food, and there is no food, so the insulin is held.

Within a day or so the person is in diabetic ketoacidosis.

That sequence is the most dangerous misunderstanding in diabetes support, and it is entirely intuitive. Insulin does not only cover food. It is required continuously for basic metabolism, and without it the body breaks down fat for fuel, producing ketones, which acidify the blood. Illness makes this worse, because the stress response raises blood glucose and increases insulin requirements at exactly the moment somebody stops eating.

So the rule, which belongs on the wall of every house supporting somebody with type 1 diabetes:

Never stop insulin during illness. Insulin requirements usually go up when somebody is unwell, not down — even if they are not eating.

The dose may need adjusting. That is the prescriber’s decision and it should be set out in advance in a written sick day plan. What must not happen is a worker deciding to skip insulin because there is no food.

This is written by a disability provider working across New South Wales with participants who have diabetes. We provide no clinical care and none of this is medical advice. The person’s own written sick day plan, from their diabetes team, governs everything described here. If somebody on insulin does not have one, obtaining it is more urgent than anything else in this guide — and in our experience it is the single most commonly missing document in diabetes care plans.

Diabetic ketoacidosis

What it is. Without enough insulin, cells cannot use glucose, so the body breaks down fat instead. That produces ketones, which are acidic. Glucose rises, ketones accumulate, the blood becomes acidic, and the person becomes profoundly dehydrated as the kidneys dump glucose and water. Untreated it is fatal.

Who gets it. Primarily people with type 1 diabetes, and anybody using an insulin pump — because pumps deliver only rapid-acting insulin, so an interruption from an occlusion, a dislodged cannula, an empty reservoir or a device failure stops insulin entirely, and ketoacidosis can develop within hours.

And people with type 2 diabetes taking SGLT2 inhibitors, which is the trap below.

What triggers it. Illness or infection. Missed or insufficient insulin. Pump failure. Surgery. Significant stress. And sometimes it is the presentation of previously undiagnosed type 1 diabetes.

What it looks like:

• Thirst, and passing large amounts of urine
• Nausea and vomiting
• Abdominal pain, which can be severe enough to be mistaken for a surgical problem
• Deep, rapid, sighing breathing — the body trying to blow off acid. This is a late and serious sign
• Breath smelling sweet or like nail polish remover — the acetone smell, which is distinctive once you have encountered it
• Dehydration — dry mouth, sunken eyes, reduced urine despite earlier excess
• Drowsiness, confusion, and eventually unconsciousness
• Weakness and lethargy

In somebody with communication disability, the presentation reduces to a pattern that workers can learn: vomiting, plus drowsiness, plus rapid breathing, in a person with diabetes, is an emergency. It does not need interpreting further. Call 000.

The abdominal pain is worth a specific note, because it causes diagnostic confusion in both directions — ketoacidosis presenting as an apparent abdominal emergency, and genuine abdominal pathology being missed because everything was attributed to the ketoacidosis.

The trap: ketoacidosis with a normal blood glucose

This one deserves its own section because it defeats the thing everybody relies on.

SGLT2 inhibitors — medications including empagliflozin, dapagliflozin and related drugs, widely used in type 2 diabetes and increasingly for heart and kidney protection — can cause diabetic ketoacidosis with blood glucose levels that are normal or only mildly raised. This is sometimes called euglycaemic ketoacidosis, and there have been safety advisories about it in Australia, particularly in relation to surgery and periods of illness or fasting.

The implication is stark. A worker checks the blood glucose, sees a reading of 8 or 9, and reasonably concludes that the diabetes is not the problem — while the person is in ketoacidosis.

What protects against it:

• Knowing whether the person takes an SGLT2 inhibitor. Check the medication list.
• Testing ketones, not just glucose, where the person is unwell — vomiting, abdominal pain, rapid breathing, drowsiness — regardless of what the glucose reading says.
• Knowing that these medications are usually withheld before surgery and during significant illness, on the prescriber’s instruction. This should be in the sick day plan and flagged before any procedure.
• Saying the medication name to paramedics and emergency staff.

If somebody you support takes one of these medications and the sick day plan does not mention ketoacidosis with normal glucose, that is a gap worth raising with the prescriber.

Hyperosmolar hyperglycaemic state

The other hyperglycaemic emergency, and the one more relevant to older people in supported accommodation — which makes it under-recognised in this sector, because ketoacidosis gets all the attention.

What it is. Seen mainly in type 2 diabetes, usually in older people. Blood glucose rises extremely high — far higher than in typical ketoacidosis — producing profound dehydration, while significant ketosis does not develop because some insulin is still present.

How it differs. It develops slowly, over days to weeks, rather than hours. There may be no vomiting and no abdominal pain. The dominant features are severe dehydration and altered consciousness. Mortality is substantially higher than for ketoacidosis.

What it looks like:

• Very high blood glucose readings
• Marked thirst and heavy urination, often for days before
• Progressive drowsiness, confusion and reduced responsiveness
• Severe dehydration
• Weakness
• Sometimes seizures or focal neurological signs, which can be mistaken for a stroke

Why it matters here specifically. This is a condition that develops over days in an older person who is becoming gradually more drowsy and drinking a lot — which in supported accommodation can be absorbed into the general picture of somebody who is “a bit off”, or attributed to a urinary tract infection, or to dementia, or to the disability.

The practical rule: an older person with type 2 diabetes who is becoming progressively drowsier and more confused over several days needs a blood glucose check and a medical assessment. Precipitants include infection, a missed medication, dehydration in hot weather, and new medications including steroids and diuretics.

What a sick day plan must contain

This is the document that prevents most of the above, and it is missing from most care plans we see. It should come from the person’s diabetes team.

• A clear statement never to stop insulin, with the specific adjustment instructions for this person
• How often to test blood glucose during illness — commonly much more frequently than usual
• When to test ketones, and what each result means, with specific thresholds and actions
• Whether the person takes an SGLT2 inhibitor, and what that changes
• Which other medications to withhold during dehydrating illness, on the prescriber’s instruction. Several classes are commonly withheld when somebody is dehydrated or vomiting — sulfonylureas, metformin, ACE inhibitors, angiotensin receptor blockers, diuretics, SGLT2 inhibitors and non-steroidal anti-inflammatories — because of the risk of kidney injury, lactic acidosis or hypoglycaemia. This must be the prescriber’s written instruction, drug by drug, not a worker’s judgement.
• Fluid instructions — how much, what kind, and what to do if the person cannot keep fluids down
• Carbohydrate when not eating — what sick day food or drink to provide to prevent hypoglycaemia while insulin continues
• If the person is on a pump, the pump failure protocol and where the backup insulin pens are
• If the person has dysphagia, what fluids and sick day carbohydrate are safe, agreed with the speech pathologist
• Who to ring, in order, with after-hours numbers
• The thresholds for going to hospital, stated as numbers and signs rather than as judgement calls
• What to do after recovery — see below

After the illness: the dose has to come down

This is a hypoglycaemia cause that is entirely predictable and entirely preventable.

Insulin requirements rise during illness and fall again afterwards. A dose increased for a chest infection and not reduced once the infection clears will cause hypoglycaemia — sometimes days later, sometimes severely.

The sick day plan should say explicitly when and how the dose returns to baseline, and who confirms it. In practice this step gets forgotten in the relief of somebody getting better, and the hypo that follows gets treated as unexplained.

The same applies to steroids. Where a short course of corticosteroids has been given for an illness, glucose requirements rise substantially and then fall when the course ends. An insulin dose adjusted upward for steroids must come down when they stop.

Hospital: the specific problems for people with disability

Hospital is where diabetes in disability goes wrong in ways nobody anticipates.

Nil by mouth and insulin. A person fasted for a procedure still needs basal insulin. Fasting plus withheld insulin in type 1 diabetes produces ketoacidosis, and procedures get cancelled or worse. This should be planned before admission, not negotiated at 6am on the ward.

The hospital takes over badly. Ward staff may not know the person’s usual regimen, may not know their hypo presentation, and may apply a generic sliding scale protocol that does not suit them. For somebody with communication disability this is a safety problem, because the person cannot say that something is wrong.

The person’s own pump and sensor. Policies vary on whether somebody can continue using their own insulin pump or continuous glucose monitor as an inpatient. For a competent self-manager this matters a great deal; for somebody with a disability whose family or workers manage the device, it matters more, because the alternative is ward staff managing an unfamiliar device. Sensors generally need removing for MRI and some imaging. Clarify before admission.

Nobody knows what a hypo looks like in this person. The single most useful thing you can hand to a ward is a one-page hospital passport: how the person communicates, how they show pain and distress, what a low blood glucose looks like in them specifically, their usual regimen and devices, what frightens them, how they are best approached, what they eat, and who to ring. One page, laminated or on the front of the file. Almost nobody produces one and it changes the quality of care immediately.

What to take to hospital: the diabetes management plan, the sick day plan, the hypoglycaemia protocol, the current medication list, the person’s own insulin and devices, the glucose meter and strips, the hospital passport, and the contact details for the usual diabetes team.

What to say on arrival: the diagnosis and type, the current regimen including any SGLT2 inhibitor by name, whether they are on a pump, the communication disability and what it means, and the most recent glucose and ketone readings with times.

Heat, which matters in Australia

Three separate problems in hot weather, and they compound.

Dehydration raises blood glucose, and in older people with type 2 diabetes is a precipitant of hyperosmolar hyperglycaemic state.

Insulin degrades in heat. Insulin left in a car in an Australian summer is no longer reliable insulin, and the person taking it will have unexplained high readings. In-use pens are kept at room temperature, which does not mean a hot car or a bag in the sun. Unopened insulin needs refrigeration without freezing.

Heat increases insulin absorption from the injection site, which can cause unexpected lows, and a hot bath or shower has the same effect.

Add to that the thermoregulation problems that come with several disabilities — spinal cord injury, some neurological conditions, some medications — and summer becomes a period for more frequent monitoring rather than less.

Gastroenteritis in a shared house

Worth naming because it is a recurring scenario and it has a predictable bad ending.

One resident gets gastro. It spreads. The resident with type 1 diabetes catches it, cannot keep fluids down, and the house is short-staffed because workers are also unwell.

What should be in place: the sick day plan, obviously; but also an infection control response that recognises the person with diabetes as the one at greatest risk, a plan for staffing when the house is affected, and a low threshold for medical review rather than waiting to see. Somebody with type 1 diabetes who is vomiting and cannot keep fluids down generally needs assessment rather than observation, because the ketoacidosis window is short.

When to call 000

Call 000 if:

• The person is unconscious, drowsy and difficult to rouse, or confused
• They are breathing deeply and rapidly
• Their breath smells sweet or of nail polish remover
• They are vomiting repeatedly and cannot keep fluids down
• Ketones are high, at the threshold the plan specifies
• There is severe abdominal pain
• Blood glucose is very high and not responding as the plan directs
• An older person has become progressively drowsier over days with high readings
• A pump user has had an interruption and is unwell
• The worker is unsure

What to say: “This is a person with type [1 or 2] diabetes who may be in diabetic ketoacidosis” — or hyperosmolar hyperglycaemic state for an older person with type 2 — “blood glucose is [reading], ketones are [reading], they take [medications including any SGLT2 inhibitor by name], and they have a communication disability.”

If the person takes an SGLT2 inhibitor, say so even if the glucose reading looks normal. That sentence may change the assessment.

The sick day checklist

• [ ] A written sick day plan from the diabetes team, current, in the file and accessible on every shift
• [ ] “Never stop insulin” stated explicitly in it
• [ ] Ketone testing equipment in the house, in date, with workers trained to use it and thresholds written down
• [ ] Whether the person takes an SGLT2 inhibitor known to every worker, with the normal-glucose ketoacidosis risk flagged
• [ ] Prescriber’s written instruction on which medications to withhold during dehydrating illness
• [ ] Sick day carbohydrate and fluids physically present
• [ ] Dysphagia-safe sick day fluids agreed with the speech pathologist, where relevant
• [ ] Pump failure protocol and backup insulin, where relevant
• [ ] A plan for returning doses to baseline after illness, with who confirms it
• [ ] A one-page hospital passport written and ready
• [ ] A pre-admission plan for fasting and procedures
• [ ] Hot weather arrangements — insulin storage, hydration, more frequent monitoring
• [ ] An escalation rule every worker knows, including that anyone can call 000 without permission