Diabetic Ketoacidosis

Question 1

What is DKA? (METABOLIC EMERGENCY)

Answer 1

(Cannot usually occur in DMT2 since there is some residual insulin, can occur in very late stages when there is absolute insulin deficiency)

• State of uncontrolled catabolism (breakdown) associated with insulin deficiency.
• No insulin > high glucose levels (decreased uptake and increased gluconeogenesis) > osmotic diuresis (dehydration and loss of electrolytes) > renal perfusion falls > accumulation of ketone bodies > acidosis.
• Vomiting > further loss of fluid and electrolytes _ progressive dehydration impairs renal excretion of H= and ketone bodies > aggravating acidosis
• Respiratory compensation > hyperventilation
• pH falls below 7, enzyme systems (pH dependant) less effective
• Stress hormones (adrenaline, noradrenaline, glucagon,, cortisol) released and aggrieve these processes
• Untreated - DKA is fatal

Question 2

Clinical presentation of DKA?

Answer 2

• 1) PEAR DROPS BREATH (ketone bodies)
  2) Profound dehydration (due to kidney action and vomiting) - shrunken eyes, tissue turgor reduced, dry tongue (in severe cases)
  3) Kussmaul breathing - respiratory compensatory hyperventilation
  4) Drowsiness, disturbance of consciousness
  5) Severe abdominal pain sometimes (can be confused for acute abdomen)
  6) Body temperature often subnormal

Question 3

Diagnosis of DKA?

Answer 3

1) Hyperglycaemia >11mmol/L
2) Raised ketone bodies >3mmol/L (with finger prick) and near-patient meter measuring beta- hydroxybuterate
3) Acidaemia blood pH<7.3
4) Metabolic acidosis - bicarbonate <15mmol/L

5) U+Es show raised urea and creatinine
6) Urine dipstick shows glycosuria and ketonuria
7) Total body K+ low but serum K+ often raised as insulin absence allows K+ to shift out of cells.

Question 4

Treatment of DKA - ABCDE and fluids?

Answer 4

1) ABCDE -
- Airway: intubate if necessary
- Breathing: give 100% oxygen if necessary
- Circulation: do bloods - glucose, U&E, ketone, blood gas.
- If a child is shocked - give fluid bolus of 10mls/kg (give less as it can cause cerebral oedema in DKA).

2) FLUIDS FIRST (but slowly):
- Maintenance fluid + (%dehydrated x 10 x weight kg)
- 5% dehydration if pH 7.1 or above - mild to moderate DKA
- 10% dehydration if pH below 7.1
- There are reduced fluid rates in DKA:
- Weight <10kg = 2ml/kg/hour
- 10-40kg = 1ml/kg/hour
- >40kg = fixed 40ml/hour

Question 5

Treatment of DKA post-fluids?

Answer 5

• Wait 1-2 hours AFTER fluid correction then give IV Insulin (wait for fluid balance as insulin will move glucose into cells which can cause a large influx of water into cells - cerebral oedema)
• Insulin drives K+ into cells so ADD POTASSIUM to fluids
• GIVE SC INSULIN at least 30 MINS before stopping IV insulin

Question 6

What factors do you monitor?

Answer 6

1) General wellbeing
2) Fontanelle tension (if neonate)
3) Pulse rate and volume,
4) Capillary refill
5) BP
6) Urine output
7) ECG
8) Blood and renal function, electrolytes and packed cell volume

Question 7

Other things to consider in treatment:

Answer 7

• In those with pump - replace pump cartridge and tubing and restart at least 60 mins before stopping IV Insulin
• Increased risk of thromboembolic disease due to increased blood viscosity (due to glucose) - keep mobile and consider stockings