Diabetic emergencies Flashcards
Why do patients with diabetic emergencies develop dehydration?
This is because of osmotic diuresis due to increased peripheral glucose. Often the glucose exceeds the urinary threshold.
Which diabetic emergency typically presents with ketones and why?
Diabetic ketoacidosis because the patients typically have complete dysfunction of insulin physiology and so ketones become their primary source of energy.
What is the triad of DKA?
Hyperglycaemia >11 Ketonaemia >3mmol/L >2+ ketonuria Metabolic acidosis pH<7.3
What process leads to the production of ketones? What are these ketones called?
Lipolysis, which is the breakdown of triglycerides to form free fatty acids which can be converted to ketones in the liver. These ketones are most typically acetoacetic acid and b-hydroxy butiric acid.
What by-product of ketone breakdown can be smelt in hepatic fetor?
Acetone
What is Kussman respiration?
Deep and laboured breathing
Why do patients develop high serum potassium?
As a result of hyperglycemic hyperosmolality, potassium shifts along with water from inside cells to the extracellular space and is lost in the urine.
Insulin normally promotes cellular potassium uptake but is absent in DKA, compounding the problem.
A total body potassium deficit therefore develops in the body, although serum potassium may be normal or even paradoxically elevated.
Insulin deficiency → hyperosmolality → K+ shift out of cells + lack of insulin to promote K+ uptake → intracellular K+ depleted → total body K+ deficit despite normal or even elevated serum K+
Why does infection pre-dispose to DKA?
Because the release of epinephrine leads to increased secretion of glucagon which results in an increased blood glucose, glycosuria and polyuria. This leads to dehydration.
What is the major risk with treating DKA?
Fluid overload and especially cerebral oedema
What is the pathophysiology of HHS?
Similar to DKA but patients are typically type 2 diabetics and so retain some small amount of insulin physiology. This means that ketones are not required and so the patients blood does not become acidic.
What is the equation for serum osmolality?
2[Na+]+glucose+urea
What is the management of HHS?
Fluid replacement Insulin Potassium replacement Thromboprophylaxis Foot protection
What is Whipple’s triad?
Low plasma glucose Symptoms consistent with hypoglycaemia Resolution of symptoms with hypo correction
Give 5 precipitating factors for DKA
- Infection
- Corticosteroid use
- Trauma
- Surgery
- Poor compliance
What is the management of DKA?
Sequential 1 litre bags of 0.9% sodium chloride saline given over progressively longer lengths of time (30 minutes, 60 minutes, 120 minutes, 240 minutes, 360 minutes)
10 units of actrapid insulin IM followed by fixed rate IV actrapid insulin at 6units/h.
40mmol/L potassium replacement therapy through IV pre-mixed 0.9% sodium chloride and potassium chloride bags.
