Diabetic ketoacidosis

Definition

An enthusiastic, but ill informed type 1 diabetes sufferer. Key mistakes he is making: not injecting subcutaneously, not testing his blood sugar level before starting, and using skanky street heroin, cut with Persil, in a mangy squat, with a strange man watching. Patients like this are at an increased risk of ketoacidosis.

A life threatening complication of having untreated Diabetes mellitus type 1, where the liver breaks down ketones and causes the body pH to drop.

Epidemiology

Around 10% of new type 1 diabetes diagnoses occur when the patient presents with ketoacidosis. The rest are usually picked up due to other symptoms presenting, such as polydipsia and polyuria. According to some study I read, DKA happens in about 0.8% of people at some point in their lives.

Pathophysiology

Basically, when insulin levels are very low - as they are in diabetes - the liver gets all scared and thinks the body is starving. So it goes into emergency mode, and starts to do its little trick of gluconeogenesis. In this, it breaks fat down, to make it into glucose. As a byproduct of this, acidic ketones are released into the blood. Thus you get two things:

1. High blood glucose level
2. Low pH level

The body doesn't like having low pH, since it screws up all of the very important chemical reactions that keep you alive.

Risk Factors

• Already having diabetes. In people who forget to take their insulin, etc, DKA can be fairly common.
• Being around 12/13 (around the age of onset of puberty).
• Family history.
• Recent viral infection (can cause autoimmune response).

Clinical Features

• Smell of pear drops on breath
• Vomiting
• Dehydration
• Abdominal Pain
• Hyperventilation, trying to reverse the acidosis
• Shock
• Drowsiness
• Coma

Investigations

• Blood glucose (>15 mmol/L)
• Urinalysis
• U&Es (dehydration)
• ABG (severe metabolic acidosis)
• Cardiac monitor (t wave changes from hypokalaemia)

Management

1. Treat shock. This is very important. Put them on a drip, but a non dextrose one - they probably don't need any more sugar.
2. Insulin. This stops the ketone production, and gets the sugar level down.
3. Gentle rehydration and Na, Ka rebalancing

Patients must be monitored, in case they have a heart attack, going into coma, etc.

Prognosis

With good treatment, more than 95% of DKAs recover fully. Generally the ones who die are those who are in a coma on admission. Causes of death are usually heart attack (from hypokalaemia), circuitatory collapse and cerebral oedema.