DKA management

Question 1

Define DKA

Answer 1

Acute, severe uncontrolled diabetes characterized by hypoglycemia, ketonaemia and acidosis.

Question 2

What are the presenting symptoms of DKA?

Answer 2

Polydipsia
Polulyuria
Abdominal pain
Nausea and vomiting
Dehydration
Drowsiness

Question 3

What is the triad of DKA?

Answer 3

Hyperglycemia >10mmol/L
Ketonaema>3+
Acidaemia <7.3

Question 4

What is the immediate management of DKA?

Answer 4

1. ABC Mx accordingly,
2. Calculate degree of dehydration give N/S
   Assess ABC and conscious level.
3. Calculate degree of dehydration and give 0.9% saline. Replace fl uid defi cit (average about 6 L) over 24 h. Give the average patient 1 L over 1 h followed by 1 L over 2 h, 1 L over 4 h, 1 L over 6 h, and then 8-hourly fl uids. Be careful in elderly patients or those with cardiac dysfunction.
4. Check serum potassium (K+). If K+ <3.3 mmol/L, withhold insulin and give 40 mmol K+ over 1 h until K+ level is ≥3.3 mmol/L. If K+ ≥3.3 mmol/L start insulin infusion at 0.1 unit/kg/h). The actual amount of insulin given is less important than regular monitoring of the blood glucose, pH and K+. If the blood glucose decreases by >5 mmol/h, then reduce insulin to 0.05 units/kg/h). If serum K+ is 3.3–5.5 mmol/L, give 20 mmol K+ in each litre of IV fl uid, to keep level at 4–5 mmol/L.
5. If serum K+ ≥5.5 mmol/L, do not give potassium but check every 2 h.

Question 5

How would you manage patient when out of DKA?

Answer 5

1. Once glucose <11 mmol/L, switch to 5% glucose and 0.45% saline or 5% glucose depending on sodium levels.
2. Prescribe insulin sliding scale.
3. Measure glucose hourly.
4. Investigate cause of diabetic ketoacidosis.
5. Depending on severity of presentation, patient may require arterial line, CVP, and nasogastric tube.

Question 6

What investigation would you do to diagnose and asses causes of DKA?

Answer 6

Blood glucose
ABG
Urine dipstick
FBC/U&E/CPR/troponin I, cultures, MSU, ECG and CXR

Question 7

Differential diagnosis

Answer 7

Sepsis • • • • • Renal failure Salicylate overdose Inborn errors of metabolism Alcoholic ketoacidosis Hyperosmolar non-ketotic coma (marked hyperglycaemia but no detectable ketoacidosis

Question 8

What are Anaesthetic considerations in patients with DKA?

Answer 8

1. The likelihood of intraoperative cardiac arrhythmias and hypotension is much reduced if the metabolic decompensation can be at least partially reversed prior to surgery. However, delaying surgery where the underlying condition will continue to exacerbate ketoacidosis is futile.
2. Resuscitation should be continued perioperatively.
3. If surgery necessary, hyperventilate to maintain respiratory compensation for metabolic acidosis—check ABGs.
4. Sodium bicarbonate is virtually never indicated. A small percentage of patients who have diabetic ketoacidosis present with metabolic acidosis and a normal anion gap. Therefore, they have fewer ketones available for the regeneration of bicarbonate during insulin administration. Consider bicarbonate in this subset of patients or if pH <7.0 and compromised.

Question 9

Hyperglycaemic, hyperosmolar, non-ketotic coma

Answer 9

1. Only occurs in NIDDM.
2. Patient is often old and presenting for the first time.
3. Presents with a long history, marked dehydration, and a glucose >35 mmol/L.
4. There is suffi cient insulin to prevent lipolysis and ketogenesis, so no acidosis.
5. Osmolality is >340 mOsm/kg.
6. Treat as for DKA but give 0.45% saline if plasma Na+ >150 mmol/L.
7. Give insulin at 0.05 units/kg/h.