Diabetic Ketoacidosis & Hyperosmolar Hyperglycaemic State

Question 1

Define DKA

Answer 1

Acute metabolic complication of diabetes characterised by complete insulin deficiency resulting in an acute hyperglycaemic state. Results in high ketoacids in urine and blood.
Glucose >11 (33)
Ketone >3
Acidosis <7.3

Question 2

What is the pathophysiology of Ketogenesis in DKA?

Answer 2

Insulin deficiency triggers:

1. Increased lipolysis and muscle catabolism
2. Result is increased FFA, glycerol and alanine
3. Glycerol + Alanine used in liver for gluconeogenesis
4. Glucagon stimulates mitochondrial conversion of FFA to ketones.
   * Insulin blocks ketogenesis by inhibiting transfer of FFA derivatives into the mitochondrial matrix

Question 3

What effect does hyperglycaemia have on electrolytes?

Answer 3

Hyponatraemia (due to polyuria)
K+ initially be normal or high due to the extracellular migration of K+ due to acidosis.
Upon treatment the K+ may drop very low and cause hypokalemia.

Question 4

Sign and symptoms of DKA (5 of 12)

Answer 4

1. Polyuria
2. Polyphagia
3. Polydipsia
4. Weight Loss
5. Weakness
6. Nausea/Vomiting
7. Abdominal Pain
8. Dry mucous membrane
9. Tachycardia
10. Acetone breath
11. Kussmaul respiration
12. Altered mental status

Question 5

What are the causes of DKA?

Answer 5

1. Acute infection
2. Myocardial Infarction
3. Stroke
4. Pancreatitis
5. Trauma
6. Corticosteroids
7. Thiazides
8. Sodium Glucose Co Transporter 2

Question 6

Name a few possible differentials for what may appear to be DKA

Answer 6

Hyperosmolar Hyperglycaemic State
Lactic Acidosis
Alcoholic Ketoacidosis
Starvation Ketoacidosis

Question 7

What is the generic treatment for DKA

Answer 7

IV Fluids (Saline and change to 5% dextrose 0.45% NaCl when glucose 11.1 mmol/L)
Potassium therapy (IV KCl)
IV insulin when K+ 3.3 mmol/L
Vasopressin (Dopamine/Noradrenaline)
Bicarbonate therapy 
Phosphate therapy

Question 8

How do you calculate serum osmolality

Answer 8

= 2[Na+] + [Glucose]/18 + [ BUN ]/2.8

if they have ingested alcohol (ethanol) it is then:

= 2[Na+ + (K+)] + [Glucose]/18 + [ BUN ]/2.8 + [Ethanol]/3.7

Question 9

Define Hyperosmolar Hyperlycaemic State (HHS)

Answer 9

Profound hyperglycaemia (glucose>33.3)
Hyper osmalality (>320 mmol/Kg)
Volume depletion in absence of significant ketoacidosis (pH>7.3, HCO3- >15mmol/L)

Question 10

Name 4 causes of HHS?

Answer 10

Infection
Cerebrovascular accident
MI
Trauma (release counter regulatory hormones ie catelocholamine, GH, glucagon, Cortisol)
Elderly bed ridden have alters thirst response
Hyperthyroidism
Acromegaly (GH)
Drugs- Corticosteroids, Thiazide, B blockers, didanosine

Question 11

Signs and Symptoms of HHS

Answer 11

Altered Mental Status
Polyuria
Polydipsia
Weight Loss
Weakness
Dry mucous membrane 
Poor skin turgour
Tachycardic
Hypotensive
Seizures

Question 12

What investigations would you carry out if a hyperglycaemia is suspected?

Answer 12

Plasma glucose (>33.3 mmol/L)
ABG (normal pH and HCO3- excludes lactate acidosis)
Urianalysis (+ glucose, leukocytes, nitrites, may be + ketones in DKA)
Serum urea, creatinine (elevated)
Serum K+ (initially hyper may become hypo once treatment commences)
Serum PO3- (normal)
Serum creatinine phosphokinase (elevated if rhabdomylosis is cause of muscle wasting)

Consider CXR, ECG, Myocardial enzymes, blood/urine/sputum culture