Diabetic Ketoacidosis (DKA)

Question 1

DKA is a common complication of:

a) T1DM
b) T2DM

Answer 1

a) T1DM

Question 2

DKA is characterised by a:

a) Absolute insulin deficiency
b) Relative insulin deficiency

Answer 2

a) Absolute insulin deficiency

Question 3

Dka is defined by a biochemical triad.

What is the triad

Answer 3

Hyperglycaemia (or known diabetes); Ketonaemia; Metabolic Acidosis

Hyperglycaemia ( >11 mmol/L) OR known diabetes

Ketonaemia (ketone bodies in the blood)

> 3 mmol/L or ketourina: > ++ on urine dip

Metabolic acidosis

pH < 7.3 or bicarbonate < 15 mmol/L

Question 4

When is ketogenesis initiated in DKA

Answer 4

When the cell’s glucose and glycogen stores are depleted

Question 5

Define the term glycogenolysis

Answer 5

Breakdown of glycogen stores into glucose

Occurs in the liver

Question 6

What is gluconeogenesis

Answer 6

formation of glucose from other substrates (not glycogen)

Question 7

What gives DKA patients their characteristic acetone smell to their breath.

Answer 7

The ketone acids

Question 8

Why do patients become dehydration in DKA

Answer 8

The hyperglycaemia overwhelms the kidneys and thus glucose starts being filtered into the urine.

The glucose in the urine draws water out with it via the process osmotic diuresis.

The extra water in the urine causes polyuria (the patient urinates more than usual)

The consequence of this is the development of severe dehydration.

This can be exacerbated by vomiting

The dehydration stimulates the thirst centre to tell the patient to drink lots of water, causing excessive thirst i.e. polydipsia.

Question 9

Patients in DKA have a potassium imbalance.

Why is that?

Answer 9

The acidotic state results in high levels of serum hydrogen ions

The cells try to compensate by exchange potassium with hydrogen (potassium moves into the blood whereas hydrogen moves into the intracellular space)

Insulin drives potassium into cells via ATPase however when insulin is depleted, potassium is no longer driven into the cells.

The serum potassium will be normal as the kidneys continue to balance blood

Total body poasttium will be low as no potassium is stored in the cells (where the majority of K is usually stored)

Question 10

When patients with DKA start insulin they can develop hypokalaemia.

Why is that

Answer 10

Insulin starts to move the excess serum potassium back into the cells (as they are potassium deplete)

Hence you get a reduction in serum potassium

Question 11

Rapid correction of dehydration and hyperglycaemia in DKA can cause what complication

Answer 11

Cerebral oedema

Question 12

Why are patients at risk of cerebral oedema if their DKA is rapidly treated

Answer 12

Rapid correction of dehydration and hyperglycaemia (with fluids and insulin) causes a rapid shift in water from the extracellular space to the intracellular space in the brain cells.

This causes the brain to swell and become oedematous, which can lead to brain cell destruction and death.

Question 13

What is the main trigger that can cause DKA

Answer 13

Infection

Question 14

Name some of the main precipitants of DKA

Answer 14

Infection (most common)

Non-compliance

Inappropriate dose alteration

New diagnosis of diabetes

Myocardial infarction

Question 15

Name the typical clinical features of DKA

Answer 15

Polydipsia (increased thirst)

Polyuria (increase in urination)

Kussmaul breathing (deep sighing breathing due to the profound metabolic acidosis)

Ketotic breath (sweet pear drop smell)

Question 16

What is Kussmaul breathing

Answer 16

deep sighing breathing due to the profound metabolic acidosis

Question 17

Name some of the generalised features of DKA

Answer 17

Nausea and vomiting

Abdominal pain

Malaise

Question 18

Name some of the clinical features of DKA that would be suggestive it is really bad

Answer 18

Dehydration

Hypotension

Confusion

Reduced GCS

Coma

Question 19

Name some of the signs of dehydration

Answer 19

Dry mucous membranes

Decreased skin turgor or skin wrinkling

Slow capillary refill (>2 seconds)

Tachycardia (>100bpm) with a weak pulse

Hypotension (<90/60mmHg)

Question 20

What is the diagnostic criteria for DKA

Answer 20

Blood glucose >11.0 mmol/L OR known diabetes

AND

Blood ketones >3.0 mmol/L OR Ketonuria (2+ or more on standard urine sticks)

AND

Bicarbonate <15.0 mmol/L and/or venous pH <7.3

Question 21

What is Euglycaemic DKA

Answer 21

This is when DKA developed with either normal or near normal blood glucose levels i.e. no or little hyperglycaemia.

Question 22

Euglycaemic DKA is a commonly associated with which anti-diabetic drug

Answer 22

SGLT2 inhibitors

Question 23

What is the principles of DKA management

Answer 23

Fluid replacement – to correct the dehydration, clear ketones and correct electrolytes

IV insulin – to fix the insulin deficiency

IV dextrose

Potassium replacement – if hypokalaemia is present

Identify and treat underlying precipitant

Question 24

Why is IV dextrose given alongside IV insulin

Answer 24

To prevent hypoglycaemia whilst the patient is a fixed rate insulin.