- Home
- Acute & General Medicine
- DKA & hyperglycaemia
DKA & hyperglycaemia
DKA is a fluid, potassium and insulin problem — in that order. Confirm it, judge how severe it is, start fluids and a fixed-rate insulin infusion, and then manage the potassium so the treatment doesn't cause the next emergency. Know how HHS differs. Built for revision, not live patient decisions.
Settle them, and check the basics
confirm · fluids · insulinRed flags — what each should make you think
DKA kills through potassium and through what caused it. Insulin drives potassium into the cells, so the potassium will fall once treatment starts. Check it at least every 1–2 hours, and always ask "why now?" (infection, missed insulin, MI, new diabetes).
The first hour (JBDS)
- IVTwo large-bore cannulas
- flFluids first
- insFixed-rate IV insulin
- K⁺Potassium in the fluids
- 🔍Find the precipitant
- ☎Diabetes team / HDU
Understand the patient — confirm and grade it
DKA vs HHSDiagnosing DKA (JBDS)
- Ketonaemia ≥3.0 mmol/L (or ketonuria 2+ or more)
- Glucose above 11 mmol/L, or known diabetes (normal glucose doesn't exclude it — SGLT2 inhibitors, pregnancy)
- Acidosis — bicarbonate below 15 mmol/L and/or venous pH below 7.3
Severe DKA markers (HDU review): ketones above 6, bicarbonate below 5, pH below 7.0, K⁺ below 3.5 on admission, GCS below 12, SpO₂ below 92%, SBP below 90, HR above 100 or below 60, anion gap above 16.
HHS is different
- Usually older, type 2 diabetes, days of illness
- Glucose ≥30 mmol/L, osmolality ≥320 mOsm/kg, no significant ketosis (ketones under 3), pH above 7.3
- Profound dehydration (often 10 L or more), high clot risk
- Fluids first — insulin only if glucose stops falling with fluids alone, or if ketones are significant; then a low dose (0.05 units/kg/h)
- Aim for a slow fall in sodium and osmolality — too fast risks cerebral oedema and osmotic demyelination
Work A–E — assess and act as you go
The diagnoses you must not miss
tap to open eachWhat points toward it, what would rule it in, and how to manage it.
Normal or high potassium at arrival that falls quickly once insulin starts. Arrhythmias, weakness.
K⁺ at 1 h, 2 h and then at least 2-hourly.
Add potassium to the fluids: K⁺ above 5.5 — none; 3.5–5.5 — 40 mmol per litre; below 3.5 — senior review, extra potassium (often via central line/HDU) and consider delaying insulin.
Mostly children and young adults, often a few hours into treatment. Headache, confusion, bradycardia, rising BP, falling GCS.
Clinical; don't delay treatment for imaging.
Senior and ITU now. Mannitol or hypertonic saline per local guidance. Avoid over-rapid fluid and osmolality shifts.
Glucose drops while ketones and acidosis persist.
Hourly capillary glucose.
When glucose falls below 14 mmol/L, add 10% glucose at 125 mL/h alongside the saline — don't stop the insulin, because insulin is what clears the ketones.
Unwell, acidotic, ketotic patient on an SGLT2 inhibitor ("-gliflozin"), often after surgery, fasting or illness. Glucose may be near normal.
Blood ketones and gas — check ketones in any unwell patient on an SGLT2 inhibitor.
Treat as DKA, with glucose infusion from the start alongside insulin. Stop the SGLT2 inhibitor.
Infection, missed insulin, new type 1 diabetes, MI, pancreatitis, drugs (steroids), alcohol.
Cultures, CXR, urine, ECG ± troponin, lipase/amylase (can be raised in DKA alone).
Treat it in parallel. DKA that won't resolve usually means the precipitant hasn't been treated.
Investigate — what to order, when, and what it tells you
test with a question in mindAt the bedside
Bloods
Find the cause
Resolution
If targets aren't being met
If ketones aren't falling by 0.5 mmol/L/h (or bicarb rising by 3/h), check the infusion and the line first, then increase the insulin rate by 1 unit/h, and get senior input.
How the plan comes together
disposition · handoverward with diabetes team
Mild–moderate DKA responding to treatment. Specialist diabetes review before discharge: education, sick-day rules, why it happened.
HDU / ITU
Severe markers, HHS with complications, low K⁺, falling GCS, pregnancy, heart or kidney failure, poor response.
Hand over: ketone, glucose and K⁺ trends, fluid given, insulin rate, precipitant.
Fix the fluid, keep the insulin running, chase the potassium, and keep asking why it happened. Most DKA deaths come from hypokalaemia, cerebral oedema, or a missed precipitant. Nicely done getting here.
Clerking template
copy or downloadDKA & hyperglycaemia — documentation structure
A structure and prompt list to help you document and think systematically. It is not a completeness check and cannot guarantee nothing is missed — use your trust's own proforma, your seniors, and your clinical judgement.
Test yourself
active recallCover the answer, say it out loud, then reveal. Retrieval beats re-reading.
0 / 12 knownFrequently asked questions
quick answersWhat are the red flags for diabetic ketoacidosis (DKA) and HHS?
- pH below 7.0 or bicarb below 5 — think severe DKA — HDU
- Ketones above 6 mmol/L — think severe DKA
- K⁺ below 3.5 on arrival — think dangerous — senior now
- GCS below 12 — think severe DKA / cerebral oedema
- Headache, falling GCS in a young adult — think cerebral oedema
- Glucose ≥30 with osmolality above 320 — think HHS
- On an SGLT2 inhibitor, glucose normal-ish — think euglycaemic DKA
- Fever, chest pain, abdominal pain — think precipitant — sepsis, MI, pancreatitis
What is the initial management of diabetic ketoacidosis (DKA) and HHS?
- Two large-bore cannulas — bloods, VBG, capillary ketones and glucose
- Fluids first — SBP under 90: 500 mL 0.9% saline over 10–15 min, repeat; otherwise 1 L 0.9% saline over the first hour
- Fixed-rate IV insulin — 0.1 units/kg/h (actual body weight); continue their usual long-acting basal insulin
- Potassium in the fluids — from the second bag, guided by the level (none if above 5.5)
- Find the precipitant — cultures, ECG, troponin if indicated, urine, CXR
- Diabetes team / HDU — severe features → senior and critical care review
Always alongside senior support and your local guideline.
What diagnoses must you not miss in diabetic ketoacidosis (DKA) and HHS?
- Hypokalaemia on treatment — insulin pushes K⁺ in
- Cerebral oedema — young · headache · falling GCS
- Hypoglycaemia on treatment — glucose falls before ketones clear
- Euglycaemic DKA — SGLT2 inhibitor · glucose under 14
- The precipitant — sepsis · MI · pancreatitis
Open each one in the must-not-miss section for what points toward it, how to rule it in, and how to manage it.
What investigations should a junior doctor order for diabetic ketoacidosis (DKA) and HHS?
- At the bedside — Hourly — aim to fall ≥0.5 mmol/L/h.
- Bloods — U&E, FBC, CRP, LFT, osmolality, lactate, cultures.
- Find the cause — MI and potassium effects.
- Resolution — Ketones below 0.6 mmol/L and venous pH above 7.3.
Admit or discharge: how is the plan decided for diabetic ketoacidosis (DKA) and HHS?
- Ward with diabetes team — Mild–moderate DKA responding to treatment. Specialist diabetes review before discharge: education, sick-day rules, why it happened.
- Hdu / itu — Severe markers, HHS with complications, low K⁺, falling GCS, pregnancy, heart or kidney failure, poor response.
Is there a clerking template for diabetic ketoacidosis (DKA) and HHS?
Yes — there is a free clerking template for diabetic ketoacidosis (DKA) and HHS on this page, structured as presenting complaint, red flags asked, history, examination (A–E), investigations, differentials, plan and escalation. You can copy it or download it as a Word document. Jump to the template.
Keep going
one more?More from Acute & General Medicine