01OverviewDefinition, clinical context and the essential points that orientate the chapter.
The glucose concentration in DKA reflects production, use, renal clearance and previous treatment; it is not the mechanism of acidosis. SGLT2 inhibition promotes glycosuria, and fasting or vomiting restricts carbohydrate delivery, while insufficient effective insulin allows lipolysis and ketone generation. The result can be clinically important acidosis without the dramatic hyperglycaemia that usually alerts staff.
Euglycaemic DKA is particularly vulnerable to cognitive error. A normal-looking meter result may lead to gastroenteritis, anxiety, starvation or sepsis being diagnosed without checking ketones. Conversely, physiological ketosis from short fasting is not automatically DKA: symptoms, blood ketone burden, pH, bicarbonate, lactate, renal function and the full clinical context distinguish emergencies.
The core treatment is not simply carbohydrate replacement. Insulin is required to switch off ketone production, while intravenous glucose protects against hypoglycaemia as that insulin continues. This material should be used alongside the current adult DKA chart, MHRA safety updates, the specific medicine licence and local perioperative or acute-illness policy.
Key points
- Euglycaemic DKA is ketoacidosis with glucose lower than expected for classic DKA, not benign nutritional ketosis with normal acid–base status.
- SGLT2 inhibitors increase urinary glucose loss, so serious ketogenesis can develop while capillary glucose appears only mildly raised or even within range.
- Test blood ketones and venous pH in an unwell exposed patient with nausea, vomiting, abdominal pain, dyspnoea, dehydration, drowsiness or unexplained high-anion-gap acidosis.
- Recognised triggers include acute illness, surgery, reduced carbohydrate or prolonged fasting, dehydration, alcohol excess, insulin omission or reduction and low endogenous insulin reserve.
- Treat confirmed disease with the dedicated adult DKA fixed-rate insulin pathway; glucose-containing fluid is commonly needed from the outset or early to permit continued insulin safely.
- Use blood rather than urine ketones for acute monitoring because urine may lag and SGLT2-associated guidance specifically prioritises blood measurement.
- MHRA advises interruption of SGLT2 treatment for major surgery or acute serious medical illness and restarting only when ketones are normal and the person is stable.
- After an SGLT2-associated DKA episode, do not restart the drug unless another cause has been identified and resolved and the specialist risk–benefit decision is explicit.
02AetiologyUnderlying causes, associations and risk factors, with why each one matters.
SGLT2 inhibitor exposure
Renal glucose loss can keep blood glucose deceptively modest while inadequate effective insulin still permits lipolysis and ketone production.
Reduced carbohydrate availability
Fasting, vomiting, perioperative restriction or very low intake lowers glucose delivery and insulin secretion while counter-regulatory hormones promote ketogenesis.
Insulin deficiency during stress
Illness, surgery, pregnancy or an inappropriate insulin reduction can create marked relative deficiency even without extreme hyperglycaemia.
03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.
- 1Effective insulin action becomes inadequate
Reduced insulin relative to physiological need removes suppression of fat breakdown and hepatic ketone formation as the process continues.
- 2Ketones generate acidosis
Fatty acids are converted into ketone bodies that consume bicarbonate, producing clinically significant high-anion-gap metabolic acidosis.
- 3Glycosuria masks the usual warning
SGLT2-mediated urinary glucose loss or low carbohydrate intake limits the glucose rise, so a reassuring meter value may delay ketone testing and treatment.
04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.
Current or recently interrupted dapagliflozin, empagliflozin, canagliflozin or ertugliflozin exposure should lower the threshold for blood ketone testing during acute symptoms.
Vomiting, abdominal discomfort, tachypnoea, malaise or drowsiness that seems too severe for the measured glucose may be the key clue to hidden ketoacidosis.
Fasting, surgical stress, reduced insulin and dehydration can combine after an operation; medication reconciliation must establish the last SGLT2 dose and current ketones.
Very-low-carbohydrate intake, prolonged starvation, vomiting or enteral-feed interruption increases ketone generation, especially when insulin has also been reduced.
Pregnancy accelerates starvation ketosis and changes normal acid–base physiology, so unwell pregnant patients need immediate obstetric and diabetes specialist assessment under the dedicated pathway.
Lactate, renal failure, toxic alcohols, salicylate and sepsis may cause or coexist with high-anion-gap acidosis; ketones do not end the diagnostic assessment.
05InvestigationsWhat to request, why it matters and how to interpret it.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Blood beta-hydroxybutyrateFirst step - Why
- Detect substantial ketonaemia promptly and follow response during insulin therapy.
- Interpretation and limitations
- Marked elevation with metabolic acidosis supports euglycaemic DKA even without glucose above 11 mmol/L; trend blood values because urine ketone clearance is delayed.
- 02
Venous pH and bicarbonate - Why
- Establish whether ketone production has caused clinically significant metabolic acidosis.
- Interpretation and limitations
- A pH below 7.3 or bicarbonate below 15 mmol/L aligns with the adult DKA acid–base criteria; mixed vomiting, respiratory or lactate effects can obscure either value.
- 03
Glucose trend rather than threshold alone - Why
- Plan safe glucose substrate without using a modest value to exclude the diagnosis.
- Interpretation and limitations
- Normal or mildly raised glucose increases the need for early carbohydrate-containing infusion during fixed-rate insulin but does not reduce the urgency of ketone suppression.
- 04
Electrolytes, renal function, lactate and calculated anion gap - Why
- Assess dehydration, potassium risk and alternative or concurrent causes of acidosis.
- Interpretation and limitations
- A raised gap supports unmeasured acids but is not specific; interpret chloride, lactate, creatinine and changing glucose with clinical fluid status and measured ketones.
- 05
Exposure and trigger review - Why
- Establish medicine timing, insulin delivery, fasting, surgery, infection, alcohol and nutritional restriction.
- Interpretation and limitations
- Identify the last SGLT2 dose and any perioperative hold, but remember pharmacodynamic glycosuria and ketone risk may persist after the tablet was stopped.
- 06
Pregnancy test where relevant - Why
- Recognise a high-risk physiological state requiring a separate multidisciplinary emergency protocol.
- Interpretation and limitations
- A positive result changes escalation, fluid and insulin oversight and fetal assessment; involve obstetric and diabetes teams immediately.
06Differential diagnosisRealistic alternatives and the features that help distinguish them.
Starvation ketosis
Short fasting can raise ketones, but severe symptoms, substantial acidosis and an insulin-deficient context support euglycaemic DKA.
Lactic acidosis
Sepsis, shock, seizure or metformin accumulation may drive the anion gap; measured lactate and ketones identify overlapping or alternative mechanisms.
Gastroenteritis
Vomiting and abdominal pain may be attributed to infection, but diabetes, SGLT2 exposure, tachypnoea or unexplained acidosis warrants immediate ketone assessment.
Toxic ingestion
Toxic alcohols and salicylates can cause high-gap acidosis with modest glucose; exposure history and targeted laboratory testing discriminate them.
07ManagementImmediate care, first-line treatment, alternatives and escalation.
01SuspectLook beyond the glucoseFirst stepAn acutely unwell person has SGLT2 exposure, fasting, surgery, pregnancy or insulin deficiency but no marked hyperglycaemia.+
- 1Check capillary blood ketones and a venous gas immediately alongside bedside glucose, renal profile, lactate, observations, fluid state and a focused cause assessment.
- 2Stop any SGLT2 inhibitor and confirm the insulin regimen, last doses, food intake and operation or illness timeline without allowing medicines reconciliation to delay resuscitation.
- 3If ketonaemia and acidosis meet the clinical DKA syndrome, activate the adult fixed-rate pathway and senior diabetes input despite a glucose value that appears reassuring.
02SuppressClear ketones without causing hypoglycaemiaEuglycaemic ketoacidosis is confirmed and ongoing insulin is required to stop lipolysis.+
- 1Use 0.9% sodium chloride according to perfusion and the current DKA chart, accounting individually for renal, cardiac, pregnancy and postoperative fluid constraints.
- 2Start fixed-rate intravenous insulin at the protocol adult rate and continue appropriate long-acting basal insulin; add glucose-containing fluid early because baseline glucose may already be below 14 mmol/L.
- 3Titrate glucose substrate through the approved chart so insulin can continue until blood ketones and acidosis resolve, monitoring potassium and delivery systems closely.
03DifferentiateRevisit persistent acidosisKetones fail to fall as expected, acidosis worsens or the clinical course does not fit isolated euglycaemic DKA.+
- 1Reassess ABCDE and confirm that weighed fixed-rate insulin reaches a patent line while substrate, fluid and potassium are administered as prescribed.
- 2Repeat ketones, gas, electrolytes, lactate and renal assessment, considering sepsis, toxic ingestion, renal acidosis, alcoholic ketoacidosis and starvation physiology where appropriate.
- 3EscalationSeek critical-care, toxicology, renal, obstetric or other specialist support according to the competing diagnosis rather than escalating insulin blindly.
04PreventMake the next interruption saferThe acute episode has resolved or an SGLT2-treated patient is approaching surgery or serious illness.+
- 1Apply the live perioperative or sick-day interruption policy, ensure blood ketones are normal and clinical stability has returned before any proposed resumption.
- 2After suspected drug-associated DKA, document the episode and obtain specialist review; MHRA advises against restarting unless another precipitant has been clearly identified and resolved.
- 3Teach symptom-led ketone testing, hydration, carbohydrate and insulin principles, emphasising that glucose can remain deceptively low and that urgent help may still be necessary.
Key medicines and prescribing safety2 treatments · regimens, roles and cautions+
Fixed-rate intravenous insulin in euglycaemic DKA
Follow the adult DKA prescription at 0.1 units/kg/hour while providing sufficient intravenous glucose to maintain safe glycaemia; specialist protocols supersede this in pregnancy, children and unusual insulin sensitivity.Do not reduce or stop the infusion solely for a normal glucose value; instead adjust prescribed substrate and assess ketone clearance. Check potassium, pump delivery and hypoglycaemia risk hourly, with senior review for missed targets or fluid restrictions.
SGLT2 inhibitor after ketoacidosis
Stop the medicine when DKA is suspected; do not restart after an associated episode unless a different cause has been identified and resolved and an informed specialist decision supports re-exposure.The drug effect may outlast the final tablet. Record the adverse event, check current licensed indication and renal status, provide interruption advice for surgery or serious illness, and do not switch within the class as an automatic workaround.
08ComplicationsImportant consequences, why they occur and why they matter clinically.
Delayed diagnosis
A modest glucose result can suppress clinical concern while acidosis, dehydration and electrolyte depletion continue to worsen.
Circulatory and kidney injury
Vomiting, glycosuria and poor intake reduce circulating volume, impair kidney clearance and intensify the metabolic disturbance.
Treatment-related hypoglycaemia
Insulin must continue until ketonaemia resolves, so inadequate accompanying glucose substrate can cause low glucose before the acidosis has cleared.
09Monitoring and follow-upTreatment response, safety checks and longer-term review.
- Follow blood ketones hourly during active therapy, using the expected fall rather than the glucose curve as the primary marker that insulin is suppressing ketogenesis.
- Check bedside glucose frequently enough to adjust intravenous carbohydrate and prevent hypoglycaemia while preserving the fixed insulin dose needed for acidosis resolution.
- Repeat venous pH or bicarbonate, potassium and renal indices through the dedicated DKA timetable, intensifying surveillance when replacement or organ function is unstable.
- Observe circulation, breathing pattern, oxygenation, consciousness, urine output and total fluid delivery; postoperative deterioration may have surgical, infective or thromboembolic causes as well.
- Document the SGLT2 product, last dose, indication, perioperative interruption and proposed long-term decision in both discharge information and the primary-care medicines record.
- Before discharge or future surgery, confirm that the patient can access blood ketone testing where indicated and understands symptom-based urgent escalation despite non-high glucose.
10Special situationsVariants, exceptions and circumstances that change the usual approach.
Glycosuria masks the warning
Renal glucose loss can keep the meter modest while insulin deficiency continues driving fat metabolism, so the apparent glucose severity becomes uncoupled from acidosis.
Insulin needs a glucose partner
In this phenotype, intravenous carbohydrate is deliberately paired with insulin so ketones can be switched off without waiting for or provoking hyperglycaemia.
Urine ketones can mislead
Urine testing reflects acetoacetate and accumulated excretion, whereas bedside blood beta-hydroxybutyrate provides a more immediate treatment trend.
Drug interruption is anticipatory
Major surgery and acute serious illness combine fasting and stress, so regulatory guidance recommends temporary SGLT2 interruption and blood-ketone monitoring before harm appears.
Not every ketosis is DKA
A fasting patient may have ketones without severe acid–base disturbance; diagnosis requires the biochemical and clinical syndrome, while uncertainty merits senior review.
Restarting needs causality review
The long-term decision is not simply made when glucose normalises; the event trigger, residual risk, medicine indication and safer alternatives must be documented.
11Common pitfallsFrequent interpretation and management errors.
- 01
Rejecting DKA because capillary glucose is 8 mmol/L even though an SGLT2-treated patient is vomiting, tachypnoeic and acidotic.
- 02
Treating only with intravenous glucose and fluid without sufficient insulin to switch off ketone production.
- 03
Using urine ketones alone to judge hourly recovery and then prolonging or stopping treatment on a lagging measurement.
- 04
Reducing fixed-rate insulin every time glucose falls instead of safely increasing the protocol glucose substrate while ketonaemia persists.
- 05
Restarting the same SGLT2 medicine automatically at discharge without causality assessment, regulatory safeguards or specialist agreement.
- 06
Attributing all postoperative high-anion-gap acidosis to the diabetes drug while failing to assess sepsis, hypoperfusion, renal failure or toxic causes.