Diabetic emergencies Flashcards
What’s the most common way for new diabetes type 1 to present?
Diabetic ketoacidosis
DKA pathophysiology
Ketogenesis occurs when there is insufficient glucose supply and glycogen stores are exhausted (such as prolonged fasting):
- The liver takes fatty acids and converts them to ketones.
- Ketones are water soluble fatty acids that can be used as fuel.
- They can cross the blood brain barrier and be used by the brain as fuel
Ate ketones always harmful?
Producing ketones is normal and not harmful in healthy patients when under fasting conditions or low carbohydrate, high fat diets
What’s characteristic about the breath of people in ketosis?
ketosis = producing ketones
characteristic: acetone smell to the breath
how to measure ketones? (2)
- urinary ketones (urine dipstick)
- blood ketones (ketone meter)
What’s raised and what’s low in DKA?
- Low glucose going into the cells
- Hyperglycaemia - as glucose stays in the blood (cannot be absorbed into the cells)
Why there is dehydration and polyuria in DKA?
- The hyperglycaemia overwhelms the kidneys, and glucose starts being filtered into the urine
- The glucose in the urine draws water out with it (osmotic diuresis)
- The patient urinates a lot (polyuria)
- This results in severe dehydration
- The dehydration stimulates the thirst centre to tell the patient to drink lots of water (polydipsia)
What does the insulin normally do to the potassium?
Insulin normally drives potassium into the cell
Potassium imbalance in DKA
- Insulin normally drives potassium into cells
- Without insulin, potassium is not added and stored in cells
- Serum potassium can be high or normal (as the kidney continues to filter blood potassium)
- However, because no potassium is stored in the cells, total body potassium can be low
- When treatment with insulin starts, patients can become hypokalaemia (low serum potassium) very quickly
What’s possible K+ imbalance with insulin treatment?
treatment with insulin -> potential hypokalaemia
*this is because insulin draws potassium into the cells
What abnormalities can DKA lead to? (5)
- Hyperglycaemia
- Dehydration
- Ketosis
- Metabolic acidosis
- Potassium imbalance
Symptoms of DKA
- Polyuria
- Polydipsia
- Nausea and vomiting
- Acetone smell to their breath
- Dehydration (hypotension)
- Altered Consciousness
- They may have symptoms of an underlying trigger (i.e. sepsis)
How often and why do we need to monitor U&Es in DKA?
U&Es should be monitored extremely closely (e.g. every 2 hours) to ensure potassium remains stable
What happens in the brain cells in DKA? What’s the danger of rapid correction/ treatment of DKA?
Cerebral oedema
- Dehydration and a high blood sugar causes water to move from the intracellular space in the brain to the extracellular space
- This causes the brain cells to shrink and be dehydrated
- Rapid correction of the dehydration and hyperglycaemia (with fluids and insulin) causes a rapid shift in water from the extracellular space to the intracellular space in the brain cells
- This causes the brain to swell and become oedematous which can lead to brain cell destruction and death
How often and why do we need to do neurological observations in DKA?
- Neurological observations (including GCS) should be monitored very closely (e.g. hourly) to look for signs of developing cerebral oedema
- Be concerned in DKA patients having headaches, altered behaviour, bradycardic episodes or changes to consciousness.
