DKA

Question 1

DKA

Answer 1

disordered metabolic state that usually occurs in the context of an absolute or relative insulin deficiency accompanied by an increase in the counter-regulatory hormones

Question 2

ketone bodies

Answer 2

found in the liver mitochondria, are derived from acetyl CoA, which is from ß oxidation of fats

they diffuse into the blood stream and peripheral tissues

Question 3

under what conditions are ketones formed

Answer 3

no glucose in the tissues - starvation and diabetes

this is because oxaloacetate will not be available for the conversion of acetyl CoA to citric acid

FFA are released from tissues by lipolysis and converted to ketone bodies by ß oxidation

Question 4

what can high levels of ketones lead to

Answer 4

acidosis

Question 5

what symptoms does high glucose excretion cause

Answer 5

osmotic diuresis - dehydration - polyuria, polydipsia

Question 6

when is DKA a danger in T1DM

Answer 6

insulin supplementation missed

Question 7

biochemical diagnosis of DKA

Answer 7

ketosis - ketonaemia >3mmol/L or significant ketonuria (>2 positives on standard urine stick)

diabetes - BG > 11.1 mmol/L or known diabetes

acidosis - bicarbonate <15 mmol/L or venous pH < 7.3

Question 8

what are some common precipitants of DKA

Answer 8

infection

illicit drugs and alcohol

non adherence with treatment - not enough insulin

newly diagnosed diabetes

steroids

pancreatitis

Question 9

how can steroids precipitate DKA

Answer 9

they can induce hyperglycaemia

therefore insulin dose should be increased during steroid treatment

Question 10

associated conditions

Answer 10

underlying sepsis and gastroenteritis

Question 11

CF

Answer 11

osmotic related - dehydration: thirst and polyuria

ketone body related - flushing, vomiting, abdominal pain and tenderness, breathlessness (Kussmauls respiration)

NB cannot smell ketones (pear drops) on all patients breath

Question 12

investigations

Answer 12

ECG, CXR

urine: dipstick and MSU
blood: capillary and lab glucose, ketones, U&Es, amylase, osmolality, ABG, FBC, blood culture

Question 13

classically, glucose at presentation

Answer 13

median level aroud 40mmol/L, from 10 - 100

euglycamia ketosis is possible

Question 14

classically, potassium at presentation

Answer 14

>5.5mmol/L

beware of the low normal

Question 15

classically, creatinine and lactate on presentation

Answer 15

creatinine raised

raised lactate common

Question 16

sodium levels

• normal presentation
• what does inc/normal Sodium indicate

Answer 16

hyponatraemia is common, hyperglycaemia increases serum osmolality (in blood), resulting in movement of water out of cells and subsequently reduction in Sodium levels by dilution

increased or normal Sodium indicates severe dehydration (water loss)

as treatment commences, Sodium concentration will rise as water enters cells

Question 17

blood ketones on presentation

Answer 17

>3 mmol/L

ßhydroxybutyrate is the ketone measured in the blood

acetoacetate is measured in the urine

Question 18

bicarbonate, amylase and WCC on presentation

Answer 18

HCO₃: <10

amylase frequently raised - pancreatitis or just salivary in origin

WCC - median around 25, doesnt always infer infection

Question 19

causes of death from DKA

Answer 19

adults: hypokalaemia, aspiration pneumonia, ARDS and co-morbidities
children: cerebral oedema

Question 20

inital managment of DKA in HDU

Answer 20

saline or fluids replaced within 30 min with 0.9% saline

tests: venous blood gas for pH, bicarbonate and lab glucose, ketones, U&Es (for Potassium and Sodium) as minimum

insulin within an hour

watch K and replace aggressively to prevent hypokalaemia and cardiac arrest

check U&Es and lab glucose every 2 hours initially

consider catheter if not passed urine by 1 hour. consider NG tube if vomiting or drowsy

prescibe LMWH to all patients

avoid hypoglycaemia (when glucose is <14mmol/L start 10% glucose alongside saline)

Question 21

why must LMWH be prescribed

Answer 21

risk of thromboembolism

Question 22

what does insulin do to K⁺

Answer 22

drives K into cells so levels can drop suddenly

this can drive the patient into cardiac arrhythmia, check wtih ECG

Question 23

after losses have been replaced in HDU, what is done

Answer 23

follow up: screen eyes, check feet and check urine albumin and bicarbonate

Question 24

blood ketone testing

Answer 24

ßhydroxybutyrate

<0.6 mmol/L is normal

optimum meter

Question 25

urine ketone testing

Answer 25

acetoacetate

indicates ketone levels 2-4 hours previously

• ketonuria persists after the clinical improvement due to mobilisation of ketones from fat tissue

Question 26

does ketonuria equate to ketoacidosis

Answer 26

no, anyone may have ketonuria after overnight fasting

if blood glucose is normal, consider alcohol

Question 27

what is often a complication in children

Answer 27

cerebral oedema

• osmolar gradient caused by high blood glucose levels results in a water shift from ICF to ECF space. Correction with IV fluids and insulin can result in a rapid reduction in effective osmorality and the development of cerebral oedema

Question 28

what are some complications

Answer 28

thromboembolism, aspiration pneumonia, hypokalaemia, hypomagnesaemia, hypophosphataemia