Revision - DKA, HHS & Hypoglycaemia

Question 1

What electrolyte abnormality is typically seen in DKA?

Answer 1

Hypokalaemia

Question 2

Triggers for DKA?

Answer 2

• 1st presentation
• missed insulin doses
• MI
• pancreatitis
• stress

Question 3

What bicarb level is seen in DKA?

Answer 3

<15

Question 4

Rate of insulin infusion given in DKA?

Answer 4

0.1 units/kg/hour

Question 5

Mx of DKA?

Answer 5

1) IV saline infusion

2) Fixed insulin infusion 0.1 units/jg/hr

3) Add 10% dextrose to infusion once blood glucose <14

4) Correct electrolyte abnormalities

5) Stop short acting insulin, continue long acting

Question 6

How does insulin affect potassium?

Answer 6

Causes potassium to be quickly taken up by cells, resulting in hypokalaemia.

Question 7

What rate of potassium infusion requires cardiac monitoring?

Answer 7

if the rate of potassium infusion is greater than 20 mmol/hour

Question 8

What blood ketone level defines DKA resolution?

Answer 8

<0.6

Question 9

If the criteria for the resolution of DKA has been met, what else is required for the patient to be switched to SC insulin?

Answer 9

The patient is eating and drinking.

Question 10

Who should the patient be reviewed by prior to discharge following DKA?

Answer 10

diabetes specialist nurse

Question 11

Investigation of suspected cerebral oedema in DKA treatment?

Answer 11

CT head and urgent senior review

Question 12

Clinical manifestations of cererbal oedema?

Answer 12

Headache, altered mental status, seizures, and focal neurological deficits

Question 13

Define hypoglycaemia

Answer 13

Hypoglycaemia occurs when glucose concentration falls below the normal fasting glucose level.

Typically below 3.3 mmol/L.

Question 14

What blood sugar level typically defines hypoglycaemia?

Answer 14

<3.3 mmol/L

Question 15

What are the 2 main causes of hypoglycaemia in diabetes?

Answer 15

1) High insulin levels:
- patient has taken too much insulin
- has used the same amount of insulin whilst not eating enough or skipping a meal or snack.

2) Sulfonylureas (e.g. gliclazide): a common adverse effect, especially when starting this medication or increasing dose.

Question 16

What diabetes drug typically causes hypoglycaemia?

Answer 16

Sulfonylureas e.g. gliclazide (as well as insulin)

Question 17

What is the action of sulfonylureas?

Answer 17

Increase insulin secretion from beta cells of pancreas

Question 18

How can hypopituitarism lead to hypoglycaemia?

Answer 18

There is a reduced secretion of GH from the pituitary (GH normally increases glucose production).

Question 19

How can Addison’s disease lead to hypoglycaemia?

Answer 19

There is reduced adrenaline and cortisol from the adrenals (these hormones increase glucose levels).

Question 20

Some normal physiological responses to hypoglycaemia:

Answer 20

1) Increased glucagon production by pancreas, reduced insulin production

2) Stimulates secretion of adrenaline from adrenal medulla

3) Stimulates secretion of GH from pituitary

4) Stimulate secretion of ACTH from the pituitary which stimulates cortisol secretion from the adrenal cortex.

Question 21

What is Whipple’s triad?

Answer 21

Whipple’s triad aids the diagnosis of hypoglycaemia.

1) symptoms or signs of hypoglycaemia

2) low blood glucose

3) resolution of symptoms with the correction of blood glucose

Question 22

What is an insulinoma?

Answer 22

a neuroendocrine tumour of the pancreas which causes unregulated secretion of insulin.

Question 23

What further tests may be useful in diagnosing the cause of hypoglycaemia?

Answer 23

1) Serum insulin: elevated in insulinoma

2) Serum C-peptide: elevated in insulinoma or sulfonylurea use

3) Serum cortisol: reduced in adrenal insufficiency or hypopituitarism

4) TSH, U&E, LFTs: abnormalities help identify secondary causes of hypoglycaemia such as hypothyroidism, chronic liver disease or kidney disease.

Question 24

What is pseudohypoglycaemia (idiopathic postprandial syndrome)?

Answer 24

A rare condition that presents with symptoms of hypoglycaemia after ingesting a meal, with a normal blood glucose level.

Question 25

Mx of hypoglycaemia in hospital if patient is unconscious?

Answer 25

1) IV glucose (e.g. 150-160 ml of 10% glucose).

2) If the patient then regains consciousness, switch to using oral glucose.

3) If IV access is not able to be established rapidly, administer glucagon 1mg via the IM or SC route.

Question 26

Mechanism of glucagon?

Answer 26

Glucagon stimulates the conversion of stored glycogen within the liver into glucose.

Question 27

Is hypoglycaemia unawareness more commonin type I or II diabetes?

Answer 27

Type II

Question 28

Is HHS more commonin type I or II diabetes?

Answer 28

Type II

Question 29

Pathophysiology in HHS:

Answer 29

1) Hyperglycaemia results in osmotic diuresis with associated loss of sodium and potassium

2) Severe volume depletion results in a significant raised serum osmolarity (typically > than 320 mosmol/kg), resulting in hyperviscosity of blood.

Question 30

If serum osmolarity is not declining despite treatment with 0.9% saline in HHS, what is the next step?

Answer 30

The fluid should be switched to 0.45% sodium chloride solution which is more hypotonic relative to the HHS patients serum osmolarity

Question 31

How is HHS managed?

Answer 31

Vigorous treatment with 0.9% saline SHOULD normalise blood glucose, bring down serum osmolarity & replace fluid losses.

Question 32

How will a reduction of serum osmolarity affect sodium?

Answer 32

A reduction of serum osmolarity will cause a shift of water into the intracellular space.

This will cause a RISE in serum sodium.

Question 33

Calculation for serum osmolality?

Answer 33

(2 x Na+) + (glucose) + (BUN)

Question 34

Cause of impaired hypoglycaemia awareness?

Answer 34

Due to neuropathy of parts of the autonomous nervous system

Question 35

Rate of dextrose infusion in DKA?

Answer 35

125 mls/hr in addition to the saline regime