Diabetic ketoacidosis in ADULTS



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
IV infusion rate
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.


Content by Dr Íomhar O' Sullivan 24/02/2004. Reviewed by Dr ÍOS 24/02/2005, 10/05/2005, 26/05/2006. Last review Dr IOS 1/03/17