Expansion
Extreme hyperglycaemia and dehydration without significant ketosis
Expansion
| Feature | DKA | HHS |
|---|---|---|
| Typical patient | Type 1, younger | Type 2, older |
| Onset | Hours to a day | Days to weeks |
| Glucose | Often 20 to 30 mmol/l | Over 30, often over 40 |
| Ketones | High | Minimal |
| pH | Under 7.3 | Normal or near normal |
| Osmolality | Raised | Over 320 mOsm/kg |
| Fluid deficit | 5 to 7 litres | 10 to 12 litres |
| Mortality | Low | Higher |
The absence of ketosis reflects residual insulin, enough to suppress lipolysis but not enough to control glucose.
Management differences
- Fluid first and slower: 0.9 per cent saline, aiming for a gradual fall in osmolality of no more than 3 to 8 mOsm/kg per hour
- Insulin later and at a lower rate, sometimes not needed initially, since fluid alone lowers glucose substantially. Starting insulin early shifts water into cells and can precipitate collapse
- Aim to lower glucose by no more than 5 mmol/l per hour
- Thromboprophylaxis is essential, since the hyperviscous state carries a high risk of arterial and venous thrombosis