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Diabetic Ketoacidosis
This is an emergency which is characterised by severe hyperglycaemia and severe acidosis, seen in diabetes.
It occurs due to lack of insulin, meaning patients cannot metabolise glucose and so the body responds by producing ketone bodies.
Symptoms
Polyuria, polydipsia
Abdominal pain
Nausea/vomiting
Ketotic breath
Compensatory deep breathing (Kussmaul hyperventilation)
Can cause confusion and seizures
Key tests
Blood gas shows acidosis (venous pH < 7.3 or HCO3– > 15 mM)
Blood glucose shows hyperglycaemia
Blood ketones > 3 mM or > 2 on a urine dipstick
Management
Start fluid infusion, e.g., 0.9% normal saline
Fixed rate IV insulin at 0.1 unit/kg/hour
Monitor blood glucose and ketones hourly
Once glucose is < 15 mM, can add 5% dextrose to prevent hypoglycaemia
Is it important to monitor potassium as insulin forces K+ into cells, so IV potassium replacement should be given and titrated to blood potassium levels
Hyperosmolar Hyperglycaemic State
This is a condition where hyperglycaemia results in osmotic diuresis, severe dehydration, and electrolyte deficiencies, due to the loss of sodium and potassium.
It leads to severe volume depletion giving raised serum osmolality (> 320 mosmol/kg), making the blood more viscous.
It can occur in type 1 diabetes, but is more commonly seen in type 2 diabetes.
Symptoms
General malaise – fatigue, nausea, vomiting
Neurological – low consciousness, headaches, papilloedema
Haematological – MI and peripheral thrombosis (due to hyperviscosity)
Cardiovascular – tachycardia, hypotension (similar to hypovolaemic shock)
May be symptoms of an underlying cause such as a precipitating infection
Key tests
Blood tests show hyperglycaemia (> 30 mmol/L) without many ketones or acidosis
Significantly raised serum osmolarity (> 320 mosmol/kg)
Management
1st is fluid resuscitation – IV 0.9% sodium chloride solution
2nd is to normalise the blood glucose:
Insulin is given if ketones are high, as fluids will naturally reduce glucose
If ketones are normal, insulin is avoided, as it can cause a rapid decline in glucose and osmolality increasing risk of central pontine myelinosis or cardiovascular collapse
3rd is to replace potassium, to prevent hypokalaemia and arrhythmias.
Hypoglycaemia
This is a state which is characterised by plasma glucose < 3.9 mM. It is very common in diabetic patients who are on insulin, but can also be due to rarer causes
Causes
These can be remembered using the acronym EXPLAIN
EXogenous drugs
Pituitary insufficiency
Liver failure
Addison’s
Insulinoma
Non-pancreatic neoplasms
Symptoms
Autonomic – sweating, anxiety, tremor, dizziness
Neurological – confusion, drowsiness, seizures, can be confused with a stroke
Management
If conscious, 15–20 g of fast carbohydrate snack (orange juice) or glucogel
If conscious but not cooperative, can put glucose gel between teeth and gums
If unconscious, start glucose IV (e.g., 10% or 20% glucose) or glucagon 1 mg IM
Once blood glucose > 4 mM, give long-acting carbohydrate e.g., slice of toast.
Insulinoma
This is a benign pancreatic islet cell tumour which is insulin secreting.
It is associated with the condition multiple endocrine neoplasia type 1 (MEN-1).
Symptoms
These are characterised by Whipple’s triad
Hypoglycaemic symptoms (e.g., drowsiness) during fasting/exercise
Measuring low blood glucose concentrations
Relief of symptoms by the administration of glucose
Key tests
Measurement of blood glucose, insulin levels and C-peptide
Supervised fasting test – normally endogenous insulin production is suppressed during hypoglycaemia, but not in an insulinoma
Imaging e.g., CT/MRI for visualisation of the tumour
Management
Definitive management is surgical removal of the insulinoma
