Synopsis
Diagnose adult diabetic ketoacidosis from ketones and acidosis, deliver protocolised resuscitation, measure biochemical response and correct the precipitating insulin deficit.
- JBDS adult diagnostic criteria combine diabetes or glucose above 11 mmol/L with blood ketones above 3.0 mmol/L or significant ketonuria and venous pH below 7.3 or bicarbonate below 15 mmol/L.
- A near-normal glucose does not exclude ketoacidosis, particularly with an SGLT2 inhibitor, pregnancy, starvation or partial insulin treatment; assess ketones and acid–base status when the syndrome fits.
- Give 0.9% sodium chloride through the weight-, circulation- and comorbidity-adjusted local schedule, documenting reassessment because both under-resuscitation and fluid overload are dangerous.
- Use a fixed-rate intravenous insulin infusion at 0.1 units/kg/hour in the standard adult pathway, while continuing the patient’s usual long-acting basal insulin unless the specialist protocol directs otherwise.
- Add glucose-containing fluid once blood glucose falls below 14 mmol/L so insulin can continue suppressing ketogenesis without driving hypoglycaemia.
- Aim for blood ketones to fall by at least 0.5 mmol/L/hour, bicarbonate to rise by at least 3 mmol/L/hour and glucose to fall by at least 3 mmol/L/hour.
- Manage potassium from measured values and repeat testing using the dedicated prescription chart; serum potassium can be high initially despite severe whole-body depletion.
- Do not finish at biochemical resolution: identify infection, missed insulin, pump failure, myocardial infarction, pancreatitis, medicines or psychosocial barriers and create a safe subcutaneous transition.
Key red flags
Polyuria, thirst, nocturia, weight loss, dry mucosa, tachycardia and reduced skin perfusion reflect hyperglycaemia and substantial volume depletion.
Nausea, repeated vomiting, diffuse abdominal pain, acetone odour and deep laboured breathing should prompt immediate ketone and venous acid–base testing.
Hypotension, hypoxia, hypothermia, oliguria, altered consciousness, very low pH or a major potassium disturbance increases mortality and requires senior critical-care assessment.
An adult without a previous diagnosis may present in DKA; obtain appropriate classification later without delaying emergency insulin and fluid treatment.
Because pump therapy uses rapid-acting insulin without a long subcutaneous depot, cannula displacement or device interruption can produce ketosis quickly despite recent apparently normal glucose readings.
Symptoms and acidosis with glucose below the classic range occur with SGLT2 inhibitors and other settings; blood ketones prevent false reassurance from the glucose value.
Investigation priorities
Confirm ketonaemia and provide a direct hourly marker of insulin-driven biochemical recovery.
Management branches
A patient with diabetes or hyperglycaemic symptoms is acutely unwell with vomiting, dehydration, abdominal pain or abnormal breathing.
- Perform ABCDE, obtain capillary glucose and blood ketones, send a venous gas with renal profile, establish monitored venous access and record weight for the insulin calculation.
- Apply the full diagnostic triad rather than glucose alone, then assess consciousness, haemodynamics, oxygenation, pH, potassium, renal function and comorbidity for the appropriate care environment.
- Call senior acute and diabetes clinicians early, involving critical care immediately for shock, severe physiological derangement, pregnancy or inability to deliver safe ward monitoring.