DKA is ketones plus acidosis; HHS is marked hyperglycaemia with high osmolality and little ketosis. Get senior help early if shocked, GCS drop, pregnant, young (18 to 25), or severe markers. Never stop long-acting (basal) insulin.
DKA diagnosis (all three)
- Blood ketones 3.0 mmol/L or higher (or urine ketones 2+ or more)
- Glucose above 11 mmol/L, or known diabetes
- Venous pH below 7.3 and/or bicarbonate below 15 mmol/L
HHS diagnosis
- Marked hyperglycaemia, often 30 mmol/L or higher
- Serum osmolality 320 mosmol/kg or higher (2 x Na + glucose + urea)
- No significant ketosis or acidosis (ketones below 3, pH above 7.3)
- Severe dehydration and high thrombosis risk
Uncomplicated DKA
- Alert, pH 7.1 to 7.29
- Ketones under 6, bicarbonate 5 to 15
- Ward level with the DKA protocol
Severe DKA (HDU)
- pH under 7.1 or bicarbonate under 5
- Ketones over 6 or anion gap over 16
- K+ under 3.5, SBP under 90, GCS drop
Peri-arrest
- Reduced consciousness, shock
- Hyperkalaemia with ECG changes
- Critical care and senior now
Parallel priorities (DKA)
1
1. Fluids
0.9% sodium chloride. If systolic BP below 90 mmHg, give 500 mL over 10 to 15 min and repeat as needed. Otherwise about 1 L over 1 h, then 1 L over 2 h twice, then slower. Slower rates in young adults, elderly, pregnancy, heart or kidney failure.
0.9% sodium chloride. If systolic BP below 90 mmHg, give 500 mL over 10 to 15 min and repeat as needed. Otherwise about 1 L over 1 h, then 1 L over 2 h twice, then slower. Slower rates in young adults, elderly, pregnancy, heart or kidney failure.
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2
2. Insulin
Fixed-rate IV insulin infusion 0.1 units/kg/h. Continue usual long-acting insulin. HHS: fluids first; start insulin 0.05 units/kg/h only once glucose stops falling with fluids or if significant ketonaemia.
Fixed-rate IV insulin infusion 0.1 units/kg/h. Continue usual long-acting insulin. HHS: fluids first; start insulin 0.05 units/kg/h only once glucose stops falling with fluids or if significant ketonaemia.
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3
3. Potassium
Check K+ before insulin. If K+ below 3.5, get senior or HDU input and replace before continuing insulin. Add 40 mmol KCl per litre when K+ is 3.5 to 5.5 and passing urine. None if K+ above 5.5.
Check K+ before insulin. If K+ below 3.5, get senior or HDU input and replace before continuing insulin. Add 40 mmol KCl per litre when K+ is 3.5 to 5.5 and passing urine. None if K+ above 5.5.
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4
4. Glucose
When glucose falls below 14 mmol/L, add 10% glucose at 125 mL/h alongside the saline and continue the fixed-rate insulin.
When glucose falls below 14 mmol/L, add 10% glucose at 125 mL/h alongside the saline and continue the fixed-rate insulin.
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5
5. Monitor and resolve
Hourly capillary glucose and ketones; VBG and U&E at 2, 4, 8, 12 and 24 h. Treat the trigger, give VTE prophylaxis. DKA resolved when ketones below 0.6 and pH above 7.3; switch to subcutaneous insulin once eating and ketones cleared.
Hourly capillary glucose and ketones; VBG and U&E at 2, 4, 8, 12 and 24 h. Treat the trigger, give VTE prophylaxis. DKA resolved when ketones below 0.6 and pH above 7.3; switch to subcutaneous insulin once eating and ketones cleared.
| Measure | Aim |
|---|---|
| Ketone fall | 0.5 mmol/L/h or more |
| Bicarbonate rise | 3 mmol/L/h or more |
| Glucose fall | 3 mmol/L/h or more |
| Add 10% glucose | when glucose below 14 mmol/L |
| Resolution | ketones below 0.6 and pH above 7.3 |
Severe DKA (consider HDU or ITU)
- Blood ketones above 6 mmol/L or bicarbonate below 5
- pH below 7.1 or anion gap above 16
- K+ below 3.5 mmol/L on admission
- GCS reduced, SpO2 low, systolic BP below 90, pulse above 100 or below 60
HHS points
- Fluid replacement is the priority; correct osmolality slowly
- Aim glucose fall 4 to 6 mmol/L/h, avoid rapid shifts
- High VTE risk: give LMWH unless contraindicated
- Screen for the precipitant and protect pressure areas
MedPrep - www.medprep.uk - Educational revision aid only. Not clinical guidance. Doses are adult examples; check the BNF, current guidelines and local policy, and seek senior advice. Nov 2026