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
- 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
3. Slow correct hyperglycaemia
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.