Diabetic ketoacidosis (DKA and HHS)

Guidelines for the Management of Diabetic Ketoacidosis in Adults, published by the Joint British Diabetes Societies Inpatient Care Group (2013) should be followed.

 

DKA and HHS Prescription Chart

Definition DKA

  1. Blood glucose > 11.0mmol/L or known diabetes mellitus

  2. Ketonaemia > 3.0mmol/L or ketonuria ++

  3. Venous bicarbonate< 15.0mmol/L and/or venous pH < 7.3

Definition Hyperosmolar Hyperglycaemic State (HHS)

  1. Hypovolaemia

  2. Blood glucose > 30.0mmol/L WITHOUT ketonaemia (ketones <3.0 mmol/L) WITHOUT acidosis (venous bicarbonate> 15.0mmol/L and/or venous pH> 7.3)

  3. Osmolality >320 mosmol/kg and/or venous bicarbonate <15 mmol/L and/or venous pH <7.3 

ONLY commence intravenous insulin therapy IF patient has significant ketonaemia (blood ketones >1.0 mmol/L or ketonuria (urine ketones >++)
A Fixed Rate Intravenous Insulin Infusion (FRIII) calculated on 0.05 units/kg body weight is recommended 

Incidence DKA

Between 4/1000 and 8/1000 patients with diabetes.
More common in type 1 diabetes but may occur in people with type 2 diabetes. 
Variants also exist: euglycaemic diabetic ketoacidosis
Low blood ketone levels and/or normal glucose levels do not always exclude DKA

Prognosis

Mortality 0.67%
Cerebral oedema, hypokalaemia, ARDS, other co-morbidities (sepsis, MI etc)

Pathophysiology

Absolute or relative insulin deficiency AND compensatory in counter-regulatory hormones (i.e., glucagon, cortisol, growth hormone, catecholamines)

INCREASED hepatic gluconeogenesis and glycogenolysis —>severe hyperglycaemia.

INCREASED lipolysis —> INCREASED free fatty acids

Energy source becomes Free Fatty Acids —> INCREASED Fatty Acid Oxidation —> INCREASED ketone bodies AND Metabolic acidosis.
Main ketone produced in DKA: 3-beta-hydroxybutyrate.

FLUID DEPLETION (hyperglycaemic osmotic diuresis, vomiting, diminished intake)

ELECTROLYTE abnormalities: hyperkalaemia/hypokalaemia need particular attention.

Symptoms and Signs

Symptoms: thirst, weight loss, inability to tolerate fluids, vomiting, diarrhoea, abdominal pain, confusion.

Signs: fruity acetone smell on breath, deep sighing respiration (Kussmaul), dehydration, hypotension, tacycradia, drowsiness, oliguria

Check for precipitating factor: sepsis, non-compliance with insulin, hypothyroidism, pancreatitis, drugs (corticosteroids, sympathomimetic drugs such as salbutamol)

Management of DKA

Intravenous fluid resuscitation:
1st bag: Normal Saline (no KCl): 1L (1hr)
2nd-5th bags: Normal Saline WITH KCL: 1L (2hr), 1L (2hr), 1L (4hr), 1L (4hr) , assuming serum K has been check and is 3.5-5.5mM

Intravenous insulin therapy:
Fixed-rate intravenous insulin infusion (FRIII) at 0.1 units/kg body weight (50U Actrapid in 50mls normal saline at fixed rate)
Once glucose<14 mM, ADD in 10% Dextrose (to run at 125ml/hr or 8hr) in parallel to ongoing normal saline infusion (permits ongoing suppression of ketogenesis)

Intravenous potassium replacement
Give 40mmol KCl per litre if K is 3.5-5.5mM
Maintain potassium between 4.0 and 5.5mmol/L

Monitoring and targets to achieve

Monitor blood ketone, glucose, pH, venous bicarbonate concentrations 2-hourly then 2-4 hourly until venous bicarbonate>15mM
Aim for:
Blood ketones should fall by at least 0.5 mmol/litre/hour
Blood glucose should fall by at least 3 mmol/litre/hour

If targets not achieved, then increase the FRIII by 1 unit/hr

Exit criteria

DKA: Blood ketones <0.6 mM AND venous bicarbonate>15 AND pH>7.3 AND eating and drinking
HHS: osmolality normalised AND eating and drinking
Transfer to subcutaneous insulin once exit criteria have been achieved: ideally give subcutaneous fast-acting insulin and a meal, and stop the insulin infusion 1 hour later.
Newly presenting type 1 patients should be given Lantus® or Levemir® at a dose of 0.25 units per kg once daily subcutaneously.

If blood parameters for DKA and HHS are normalised, but still not eating and drinking, then switch from fixed rate iv insulin infusion to variable rate iv insulin infusion

Variable rate iv insulin infusion + 10% Dextrose/0.15% KCl at 50ml/hr

CBG Insulin units/hr
>14. 6
12.1-14. 4
10.1-12. 3
7.1-10. 2
4-7 1
<4. 0.5

Subcutaneous basal insulin

Established subcutaneous therapy with long-acting insulin analogues (insulin detemir or insulin glargine) should be continued during treatment of diabetic ketoacidosis.

Additional treatments

Prophlyactic anticoagulation
Antibiotics




Dr Rajesh Varmadiabetic ketoacidosis