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. DKA requires hospital treatment: intravenous insulin, fluids, and electrolyte replacement.
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. 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.
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 urgent hospital assessment, even when glucose levels appear only mildly elevated. Pregnancy increases DKA risk, and DKA can occur at lower blood glucose levels than in non-pregnant individuals.
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 and orientation | 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: this causes dehydration and may make insulin administration difficult |
| Blood ketones (if tested) | Under 0.6 mmol/L: normal | 1.6 to 3 mmol/L: urgent assessment needed. Over 3 mmol/L with DKA symptoms: call 999. Over 3 mmol/L without symptoms: urgent same-day specialist contact. |
| Abdominal pain | Mild stomach discomfort, perhaps related to nausea | Significant abdominal pain accompanying nausea or vomiting: a classic DKA symptom that warrants urgent assessment |
| Urine ketones (if dipstick available) | Negative or trace | 2+ or more on urine dipstick supports a concern for DKA, but urine ketones lag behind blood levels by several hours and should not be used in isolation to guide management |
| Blood 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? If not, can you direct them to do so now?
Can they tolerate fluids? Persistent vomiting causes dehydration and may make 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. Act on symptoms.
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: symptoms with ketones above 3 mmol/L, confusion, or Kussmaul breathing. Call 111 or diabetes team: ketones 1.6 to 3 mmol/L.
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 when insulin delivery is interrupted
- 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
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: act on the symptoms, not the glucose.
- Blood ketones above 3 mmol/L with DKA symptoms means 999. Blood ketones 1.6 to 3 mmol/L, even if symptoms are mild or unclear, should prompt same-day specialist advice or NHS 111 assessment.