diabetic ketoacidosis

Question 1

DKA is a triad of

Answer 1

hyperglycaemia
metabolic acidosis
increased total body ketone concentration

Question 2

DKA results from

Answer 2

absolute or relative deficiency of circulating insulin and the effects of increased levels of counter-regulatory hormones

Question 3

biochemical criteria for the diagnosis of DKA

Answer 3

1. hyperglycaemia >11mmol/L
2. Ketoanaemia (blood bethydroxybutyrate >3mmol/L or moderate or large ketonuria)
3. acidosis: venous pH <7.3 or bicarbonate <15mmol/L

Question 4

euglycaemia ketaacidosis

Answer 4

rarely DKA may present with near normal glucose levels

Question 5

if a child is hyperosmolar with very high BGL >30mmol/L, with little or no acidosis or ketones

Answer 5

this is a hyperosmolar hyperglycaemia state (HHS)
requires completely different treatment
discuss with senior doctor

Question 6

causes and precipitants of DKA

Answer 6

insufficient insulin, newly diagnosed type 1 diabetes
missed insulin dose
infection/illness

Question 7

assessment

Answer 7

1. is the patient shocked/haemodynamically stable?
2. assess ABCs and fluid resuscitate
3. contact ED consultant, PCC and endocrinology
4. confirm diagnosis and determine causes

Question 8

symptoms of DKA

Answer 8

polyuria
polydipsia
weight loss
abdominal pain
weakness
nausea and vomiting
confusion

Question 9

signs of DKA

Answer 9

dehydration
deep sighing respiration (Kussmaul)
smell of ketones

Question 10

biochemistry prior to arrival

Answer 10

elevated BGL >11mmol/L
acidaemia pH <7.3
moderate or large ketones in urine and/or blood ketonaemia

Question 11

goals of therapy are to

Answer 11

correct dehydration
correct acidosis and reverse ketosis
restore normal BGL
avoid complications of therapy

priorities are fluid resus then insulin

Question 12

children who are alert, not clinically dehydrated and not nauseated or vomiting

Answer 12

do not always require IV fluids even if their ketone levels are high
usually tolerate oral rehydration and subcut insulin
they do require monitoring regularly to ensure they are improving and their ketone levels are falling

Question 13

general resuscitation for shocked or haemodynamically unstable patients

Answer 13

airway
ensure airway is patent or provide airway support eg. airway manouvres, gueddel airway or endotracheal tube
Breathing
give oxygen by facemask
Circulation
measure blood pressure and heart rate and capillary refill time
cardiac monitor for T waves (peaked in hyperkalaemia)
insert two IV cannulas for resuscitation and blood sampling

Question 14

APLS definition of shock

Answer 14

tachycardia, prolonged central capillary refill, poor peripheral pulses and hypotension (though this is a late sign of shock)

Question 15

how much fluid should non shocked patients get

Answer 15

all children and young adults with mild, moderate or severe DKA who are not shocked and are felt to require Iv fluids should recieve a 10ml/kg sodium chloride 0.9% bolus over 60 minutes

Question 16

how much fluid should shocked patients get

Answer 16

20ml/kg bolus of sodium chloride 0.9% over 15 minutes
following this, reassess and administer further boluses of 10ml/kg if required
to a limit of 40ml/kg, at which point ionotropes should be considered

Question 17

why should excessive fluid be avoided

Answer 17

risk of cerebral oedema

Question 18

initial investigations

Answer 18

blood glucose
blood gasses (venous or capillary)
FBC
urea and electrolytes, electrolytes on blood gas machine are acceptable and the same measuring system should be used throughout management of DKA
ketones (beta-hydroxybutyrate)
new diagnosis bloods including HbA1c when possible during first admission

Question 19

raised white blood cell count in DKA

Answer 19

common, does not necessarily indicate infection

Question 20

clinical assessment when admitting a patient with DKA

Answer 20

conscious level - hourly neurological examinations
comprehensive examination - look for cerebral oedema, infection, ileus (common in DKA)
weigh patient

Question 21

signs of cerebral oedema

Answer 21

headache, irritabillity, slowing pulse, lethargy, incontinence, thermal instability
papilloedema is a late sign

Question 22

potassium replacement therapy is required because

Answer 22

there will be a total body deficit of potassium and correction of the acidosis in the absence of potassium therapy will usually rapidly result in hypokalaemia (levels in the blood will fall once insulin is commenced)

Question 23

monitoring during potassium infusion

Answer 23

continuous ECG monioring
if serum potassium is >5mmol cease potassium infusion

Question 24

bicarbonate administration

Answer 24

not routinely recommended
except for rare circumstances in extremely sick children

Question 25

what happens to phosphate levels in DKA

Answer 25

depletion of intracellular phoshate occurs in DKA and phosphate is also lost form osmotic diuresis
plasma phosphate levels fall after starting treatment and this is execerbated by insulin promoting phosphate netry into cells
consider phosphate replacement

Question 26

potential complications of DKA

Answer 26

1. hyper/hyponatraemia
2. hypoglycaemia
3. cerebral oedema

Question 27

preventing hypoglycaemia

Answer 27

if the blood glucose levels fall too low and the patient is still ketotic, give IV glucose, do not discontinue insulin

Question 28

when might cerebral oedema develop

Answer 28

may suddenly develop clinically, usually between 6-12 hours after starting therapy

Question 29

prevention of cerebral oedema

Answer 29

slow correction of fluid and biochemical abnormalities

Question 30

very late signs of cerebral oedema

Answer 30

rising blood pressure, bradycardia and respiratory impairment