Diabetic Ketoacidosis (DKA)
DKA is an acute metabolic complication of diabetes that is potentially fatal and requires urgent medical attention. It is characterised by an absolute or relative insulin deficiency and is the most common acute hyperglycaemic complication of Type 1 diabetes.
Pathophysiology
Ketoacidosis - This occurs as the body enters a state of starvation, so it gets its energy from ketogenesis. Kidneys then produce bicarbonate to try and buffer the ketones, but over time the ketones become too much → Acidosis.
Dehydration - Glycosuria draws water out into the urine in a process called Osmotic Diuresis → Polyuria and Polydipsia
Hyperkalaemia - Lack of insulin means potassium can’t be driven into cells, thus staying in the circulation.
It's important to monitor patients during management as, when insulin is given, there's a huge push of this potassium into cells, therefore potentially causing severe hyperkalaemia. This can lead to fatal Arrhythmias.
The most important aspect in DKA management is Fluid resuscitation as its the thing that will kill patients first.
Presentation
Usually triggered by infection, emotional/physical stress, or dehydration
Dehydration
Polyuria, Polydipsia
Abdominal pain
N+V
Altered consciousness
O/E – Kussmaul breathing, Fruity breath (Acetoacetone), Hypotension (may even go into hypovolemic shock)
Diagnosis
DKA:
Diabetes – > 11mmol/L
Ketosis - > 3mmol/L
Acidosis - < 7.3
Management
The 1st thing to do is Fluid Resuscitation!
Initial bolus of 10ml/kg 0.9% NaCl over 60 mins - Add KCl in every 500 ml and monitor K+ closely
This shouldn't be done too quickly as it increases the risk of cerebral oedema
1-2 hours after fluids are given, the patient should be started on a Fixed-rate Insulin infusion at 0.05-0.1units/kg/hour.
N.B. Trust guidelines should always be consulted for this.
Other things to do include:
Monitor glucose, ketones, pH, GCS
Avoid hypoglycaemia with dextrose if glucose falls < 14mmol/L
Monitor for signs of cerebral oedema e.g. unequal pupils, lower GCS etc.
Complications
The main complication that can occur during management is Cerebral Oedema.
Dehydration and hyperglycaemia cause water to move out of brain cells, which causes them to shrink. Rapid correction of this dehydration and hyperglycaemia causes lots of water to move back into the cells very quickly, therefore causing oedema + cell lysis
This can be managed with IV Mannitol, Hypertonic saline, or giving the IVF more slowly
Other complications that can occur here are Hypoglycaemia and Hypokalaemia.