Diabetic Ketoacidosis

Question 1

Define diabetic ketoacidosis

Answer 1

Decreased insulin causes increased gluconeogenic hormone release by liver.
Causes massive glucose release + decreased uptake by tissues (leads to osmotic diuresis).
Also increased lipolysis + ketone generation. This leads to metabolic acidosis.

Question 2

List 5 possible precipitating factors to DKA

Answer 2

Infection
Discontinuation of insulin (unintentional or deliberate).
Inadequate insulin.
CVD eg, stroke or MI
Drugs eg, steroids, thiazides or SGLT2 inhibitors.

Question 3

What is the epidemiology of DKA?

Answer 3

4% of T1DM/ year

Question 4

What physiological processes may initiate DKA?

Answer 4

Any physiological stress e.g. pregnancy, trauma or surgery

Some women > risk at the time of menstruation

Question 5

Which 3 biochemical findings characterise DKA?

Answer 5

Hyperglycaemia
Acidosis
Ketonaemia

Question 6

What readings of blood glucose, bicarbonate and ketones would be seen in DKA?

Answer 6

Ketonaemia: >, 3 mmol/L or significant ketonuria (>2+)
BG >11 mmol/L or known DM
Bicarbonate < 15 mmol/L +/or venous pH < 7.3.

Question 7

Why is blood glucose not a reliable indicator of DKA?

Answer 7

BG may be normal/ only slightly elevated

Question 8

What is the timing of onset in DKA?

Answer 8

24 hours

Question 9

What are 5 common signs and symptoms of DKA?

Answer 9

N+V
Abdo pain
Polyuria
Polydipsia
Dehydration

Question 10

What are 6 other signs and symptoms that may present in DKA?

Answer 10

Kussmaul respiration (resp compensation of acidosis)
Acetone smell (like pear drops) on the breath
Weakness
Lethargy
If severe- altered mental state (inc. coma)
Weight loss

Question 11

What are 6 gross signs of dehydration seen in a patient with DKA?

Answer 11

Dry mucous membranes.
Decreased skin turgor/ skin wrinkling.
Sunken eyes.
Slow capillary refill.
Tachycardia with weak pulse.
Hypotension.

Question 12

What investigations are performed on examination in a patient with suspected DKA?

Answer 12

Check temperature, pulse + BP
Smell breath for characteristic fruity/musty odour of ketones
Examine chest for signs of pneumonic consolidation.
Check CVS for signs of cardiac failure, pericardial rub + murmurs.
Examine abdomen for intra-abdominal precipitant.
Assess mental status + orientation.
Perform a screening neurological examination.
Check skin for evidence of abscesses, boils or other rashes.

Question 13

What 8 investigations may be performed in a patient with suspected DKA?

Answer 13

Capillary BG
Urine dipstick
Blood test
12-lead ECG.
CXR.
Abdominal X-ray 
Head CT/MRI: if impairment of consciousness or focal neurology.
LP: if meningitis is possible precipitant.

Question 14

What do FBC, U+Es and ABG show in a blood test of a patient with DKA?

Answer 14

FBC: High WCC
U+Es: high U/Creat,
VBG (metabolic acidosis with low HCO3 + high anion gap)

Question 15

Describe the immediate management of a patient with DKA

Answer 15

ABC
Saline fluid replacement 
K+ replacement
Tests: bloods, CXR, ECG
IV Insulin
Monitor CBG, Ketones, VBG
LMWH
NBM for 6h, NG tube if GCS is reduced

Question 16

List 7 complications of DKA

Answer 16

Cerebral oedema
Pulmonary oedema
Iatrogenic hypoglycaemia
Iatrogenic hypokalaemia.
Diabetic retinopathic change prior to/ after tx for DKA.
Hypophosphataemia
ARDS

Question 17

List 3 cardiac or vascular related complications of DKA

Answer 17

Cardiac dysrhythmia due to electrolyte disturbance (esp. K+) or metabolic acidosis.
Venous thromboembolism.
MI (cause or complication of DKA).

Question 18

Describe the prognosis for DKA

Answer 18

Mortality rate: 0.67%.

Question 19

What are poor prognostic indicators in DKA?

Answer 19

Age
Nature + severity of underlying precipitating pathology (esp. MI, sepsis + pneumonia).
Presence of coma, hypothermia or persistent oliguria

Question 20

What are the main causes of mortality due to DKA in young and older patients?

Answer 20

Young: Cerebral oedema
Old: Severe hypokalaemia, ARDS + co-morbid states (pneumonia, acute MI + sepsis)