Diabetic Ketoacidosis: Recognising the Emergency
A community pharmacy triage guide to recognising diabetic ketoacidosis, including ketone thresholds, the SGLT2 inhibitor trap, sick day rules, and when to call 999.
Why this matters
Diabetic ketoacidosis (DKA) is a life-threatening medical emergency caused by a severe shortage of insulin. Without insulin, the body breaks down fat for energy, producing acidic by-products called ketones. When ketones accumulate faster than the body can clear them, the blood becomes acidic and the patient can deteriorate rapidly, particularly in children and those using insulin pumps.1
Community pharmacists may be the first healthcare professional consulted when DKA is developing. Knowing the warning signs, asking the right questions, and responding appropriately can significantly affect the outcome.
DKA most commonly affects people with type 1 diabetes, but it can occur in anyone treated with insulin, in newly presenting undiagnosed type 1 diabetes (particularly in children), and in people taking sodium-glucose cotransporter-2 (SGLT2) inhibitors such as empagliflozin, dapagliflozin, canagliflozin, and ertugliflozin.4 Patients on SGLT2 inhibitors can develop DKA with a normal or near-normal blood glucose level. This is known as euglycaemic DKA, and it is frequently missed because the glucose reading does not raise concern. Any person on these medicines presenting with DKA symptoms needs urgent clinical assessment regardless of what the glucose meter shows. In SGLT2 inhibitor patients, blood ketone testing is preferred to urine testing where available, as urine ketone testing may be less reliable in this context.5
DKA can also occur during pregnancy at lower blood glucose levels than would typically trigger concern. Any pregnant person with diabetes presenting with DKA symptoms warrants immediate hospital assessment, even when glucose levels appear only mildly elevated.1,2
Red flags vs More likely benign
| Feature | More likely benign | Red flag ⚠ |
|---|---|---|
| Breath odour | No unusual smell, or mild halitosis | Sweet, fruity or acetone-like smell, often described as pear drops or nail varnish remover |
| Breathing pattern | Normal rate and depth at rest | Deep, laboured, often rapid breathing (Kussmaul respiration): the body attempting to correct blood acidity. This is a late and serious sign. |
| Consciousness | Alert, fully orientated, conversational | Drowsy, confused, difficult to rouse: this indicates severe acidosis and requires 999 immediately |
| Nausea and vomiting | Mild nausea, tolerating fluids | Persistent vomiting, unable to keep fluids down: causes dehydration and makes insulin administration difficult |
| Blood ketones (if tested) | Under 0.6 mmol/L: normal. 0.6 to 1.5 mmol/L: low; follow sick day rules if otherwise well. | 1.6 to 3 mmol/L: urgent assessment needed. Over 3 mmol/L: advise immediate A&E assessment or call 999 regardless of whether DKA symptoms are clearly present. |
| Urine ketones (if tested) | Negative or trace | 2+ or more should be treated as high ketones. Do not wait for blood ketone confirmation if DKA symptoms are present or the patient is unwell. Advise immediate A&E assessment or call 999. |
| Abdominal pain | Mild stomach discomfort perhaps related to nausea | Significant abdominal pain with nausea or vomiting: a classic DKA symptom that warrants urgent assessment |
| Glucose on SGLT2 inhibitor | Normal glucose, no symptoms | Normal or only mildly elevated glucose with DKA symptoms: euglycaemic DKA. Do not be reassured by the glucose reading. |
Think DKA if Your Patient Says...
These phrases from any person with diabetes should raise immediate suspicion. You do not need a high glucose reading to act. The clinical picture matters more than any single number.
- "I cannot stop being sick."
- "I am drinking constantly but cannot quench my thirst."
- "I am going to the toilet every hour."
- "I feel completely exhausted."
- "My glucose will not come down no matter how much insulin I take."
- "I have lost weight without trying." (Consider new-onset type 1 diabetes, particularly in a child or young adult presenting with thirst, frequent urination, and unusual tiredness.)
- "My stomach is really hurting." (Abdominal pain is a classic DKA symptom and commonly accompanies nausea and vomiting.)
Any patient with or without a known diabetes diagnosis presenting with thirst, frequent urination, vomiting, and confusion should be assessed for DKA. In children, DKA is sometimes the first presentation of type 1 diabetes.
🛑 KETONES: A Quick Assessment Framework
Use this prompt list when any person with diabetes presents feeling unwell.
Has the patient tested blood or urine ketones? Blood ketone testing is preferred, especially in people on SGLT2 inhibitors.
Can they tolerate fluids? Persistent vomiting causes dehydration and makes insulin administration difficult or unreliable.
Excessive thirst and frequent urination suggest high glucose or possible new-onset type 1 diabetes.
Empagliflozin, dapagliflozin, canagliflozin, or ertugliflozin: DKA can occur at normal blood glucose. If DKA is suspected, the SGLT2 inhibitor should be stopped immediately and urgent medical assessment sought.
Persistent vomiting is a red flag. Abdominal pain is also a classic DKA symptom. Both accelerate deterioration.
Any alteration in consciousness or marked confusion requires 999 immediately.
Call 999: blood ketones over 3 mmol/L, urine ketones 2+, confusion, Kussmaul breathing, collapse. Urgent same-day assessment: ketones 1.6 to 3 mmol/L or any DKA concern on SGLT2 inhibitor.
Common DKA Triggers
Recognising what brings on DKA helps the pharmacist ask the right questions. There is not always an obvious cause, but these are the most common.
- Missed, reduced, or incorrectly administered insulin doses
- Insulin pump failure or accidental dislodgement: pump users can develop DKA very rapidly because only rapid-acting insulin is being delivered. Suspected pump failure with ketones or DKA symptoms requires urgent specialist advice or emergency assessment. Do not rely on repeated pump bolus corrections if delivery failure is suspected.
- Acute illness: chest infection, urinary tract infection, and gastroenteritis are particularly common triggers
- New-onset type 1 diabetes: thirst, polyuria (frequent urination), unexplained weight loss, and lethargy in a child or young adult may be the first sign
- SGLT2 inhibitor use: can trigger DKA at normal blood glucose levels, even in type 2 diabetes
- Surgical procedures, physical injury, or serious acute illness such as a heart attack
- Excessive alcohol intake or prolonged fasting
If DKA symptoms are present, do not wait for a clear trigger before acting.
What to do in pharmacy
Do not advise the person to drive. Ask someone to take them or call 999. Ask them to bring all their medicines. If DKA is suspected in a person taking an SGLT2 inhibitor, advise them to stop taking it immediately and not to restart unless advised by a clinician after DKA has been excluded or treated.4,5
Pregnant patients require immediate hospital assessment because DKA can occur with only modest glucose elevation, and the condition can deteriorate rapidly with consequences for both mother and fetus.1 Do not manage through pharmacy advice or routine GP referral.
Pharmacy cannot manage DKA. The person needs clinical assessment.
Seek urgent medical help without delay if vomiting starts, symptoms worsen, ketones rise above 1.5 mmol/L, breathing changes, confusion develops, or the patient cannot keep fluids down. Do not return to the pharmacy as a first step if any of these red flags develop: they require medical escalation.
Key takeaways
- Any person with diabetes who is vomiting persistently, becoming confused, breathing deeply and rapidly at rest, or has fruity-smelling breath needs urgent hospital assessment.
- Patients on SGLT2 inhibitors can develop DKA with a completely normal blood glucose reading. If DKA is suspected, advise them to stop the SGLT2 inhibitor immediately and seek urgent medical assessment.
- Blood ketones above 3 mmol/L or urine ketones 2+ in an unwell patient means emergency assessment, not specialist-only contact. Do not downgrade based on absence of obvious symptoms.
📚 References
- Joint British Diabetes Societies for Inpatient Care. The management of diabetic ketoacidosis in adults. 4th ed. JBDS-IP; 2023. https://www.diabetes.org.uk/professionals/position-statements-reports/specialist-care-for-children-and-adults-and-complications/the-management-of-diabetic-ketoacidosis-in-adults
- National Institute for Health and Care Excellence. Diabetic ketoacidosis. NICE Clinical Knowledge Summary. London: NICE; 2022. https://cks.nice.org.uk/topics/diabetic-ketoacidosis/
- National Institute for Health and Care Excellence. Type 1 diabetes in adults: diagnosis and management. NG17. London: NICE; 2022. https://www.nice.org.uk/guidance/ng17
- Medicines and Healthcare products Regulatory Agency. SGLT2 inhibitors: updated advice on the risk of diabetic ketoacidosis. Drug Safety Update. 18 April 2016. https://www.gov.uk/drug-safety-update/sglt2-inhibitors-updated-advice-on-diabetic-ketoacidosis
- Medicines and Healthcare products Regulatory Agency. SGLT2 inhibitors: recommendations to reduce risk of diabetic ketoacidosis during surgery and other procedures. Drug Safety Update. July 2020. https://www.gov.uk/drug-safety-update/sglt2-inhibitors-recommendations-to-reduce-risk-of-diabetic-ketoacidosis-during-surgery-and-other-procedures
- Dhatariya KK, Vellanki P. Treatment of diabetic ketoacidosis (DKA) in adults. Diabetes Care. 2017;40(12):e180-e181. https://diabetesjournals.org/care/article/40/12/e180/36917/
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Disclaimer: For educational use by healthcare professionals only. Does not replace clinical judgement, local pathways, or NICE guidance. Not for public self-diagnosis.