Pathophysiology
Relative insulin deficiency = ↑Glu, ↓pH and ketonaemia.
↑glucagon, cortisol, catecholamines⇒ ↑ gluconeogenesis ⇒ ↑↑ glucose.
↑ lipolysis ⇒ ↑ FFA - ketogenesis - metab acidosis (3-β-hydroxybutyrate).
Dehydration 2°: osmotic diuresis & vomiting = electrolyte (K+⇑ or K+⇓) shifts.
Mortality from
- Children: Cerebral oedema
- Adults: ⇓K+, ARDS, co-existing sepsis/ AMI etc
Criteria
- Blood glucose >13.8 mmol/L
- Blood pH < 7.3, (Serum bicarb. < 18 mmol/L)
- Anion gap > 10
- Blood ketones > 3 or ketonuria (>++ o dipstick)
Aims and principles
1. Replace lost fluid & electrolytes
2. Correction of ketoacidosis
- Insulin suppression of ketogenesis
- Insulin stimulated entry of glucose into cells (correct ketonaemia)
- To achieve this you need to give enough insulin to correct the acidosis. Once the blood glucose falls you will often need to support the insulin with infused dextrose
3. Slow correct hyperglycaemia
- aim for glucose fall 3-5 mmol/l/hr only
- allow acidosis to correct as above
- No bicarb. unless pH < 6.9 If necessary use IL 1.26% solution + 20 mmol KCl
4. Treat cause
Resuscitate
A, B, C
Fluids (adults)
- 1L over 1hr
- 1L over 2hr
- 1L over 4hr
- 1L over 8hr
- When Glu. <12mmol/L change to 5% dextrose
- When Glu. >12mmol/L change to normal saline
- If hypoglycaemia consider 10% dextrose
- If Glu. drops too quickly ↓insulin infusion rate
Potassium
Not added to 1st litre until urine output established
| Serum K+ | Add |
|---|---|
| >5 | None |
| 3.5 - 5.0 | 20mmol/L |
| <3.5 | 40mmol/L |
Insulin
- Start infusion at 0.1U/Kg/hour
- Later move to sliding
| Cap Glu. (mmol/L) |
Units / hr (=ml / hr) |
|---|---|
| 0 - 4 | 0 |
| 4.1 - 6 | 0.5 |
| 6.1 - 8 | 1 |
| 8.1 - 10 | 2 |
| 10.1 - 12 | 3 |
| 12.1 - 16 | 4 |
| 16.1 - 20 | 6 |
| > 20 | Call doctor |
Consider
- CVP
- NT tube
- Urinary catheter
- Heparin
For patients on basal bolus insulin (e.g. Glargine, Detemir) it should be continued where possible.
Initial investigations
- Blood glucose, U&E, blood gas
- FBC, Cultures as required, Osmolarity
- CXR
- ECG
Hyperosmolar Hyperglycaemic State
- HSS [HONC] (elderly) - may have ++ ketones but are not acidotic
- Principles of Mx same as DKA
- Aim for slow correction metabolic adnormalities
- Prophylactic anticoagulation (unless contraindicated)
Additional Mx
- Monitor intake/output
- Hourly glucose monitoring. Aim for drop 4-5mmol/L/hr. Avoid rapid reduction.
- Check ketones every 1-2 hour
- Check K+ every 2-4 hrs (need ECG monitor?)
- Inform endocrine team of patient
- Do not use bicarbonate without prior discussion with EM senior/endocrine agreement
- Common DKA precipitants include infection, MI or insulin omission
- SC insulin should be resumed after the patient is euglycaemic, ketone free and eating/drinking normally. Allow 30 minute overlap after 1st injection of rapid-acting insulin before the insulin infusion is stopped
- Reinforce diabetes education re DKA prevention / sick day rules prior to discharge