Diabetes complications Flashcards
what are acute complications of diabetes mellitus?
arise from events associated with
1) hyperglycaemia
2) diabetic ketoacidosis (DKA)
3) hyperosmolar hyperglycemic state (HHS)
4) hypoglycaemia
define diabetic ketoacidosis
profound deficiency in insulin
- fats metabolized in the absence of insulin
what is DKA characterized by?
1) hyperglycaemia
2) ketosis
3) metabolic acidosis
4) dehydration (volume depletion)
who usually gets DKA?
most often occurs with type 1 DM but may be seen in type 2 in conditions with severe illness or stress when pancreas cannot meet the demand for insulin
what are some factors that can precipitate DKA?
illness, low insulin storage, insulin omission, undiagnosed type 1 DM
Explain the pathophysiology of DKA
insulin supply is insufficient and glucose cant be used for energy so the body breaks down fat stores for fuel which results in the products of ketones which are acidic. With ketones in the body that means you’re in ketosis which alters the pH of the body. This shift in pH = metabolic acidosis. When this occurs the body tries maintain the balance by trying to to get rid of ketones through urine. this process is called ketonuria. since you are eliminating ketones through urine, electrolytes specifically cations are also being depleted
what does insulin deficiency cause in terms of protein?
impairs protein synthesis = excessive protein degradation resulting in nitrogen from tissues. the stimulates the production of glucose from amino acids (from proteins) in the liver which leads to further hyperglycaemia (body cannot lower blood glucose due to insufficient insulin). glucose spills over into renal tubules (glycosuria) and draws a large amount of water that leads to increase urine output (osmotic diuresis) = severe depletion of electrolytes specifically potassium.
- acidosis causes hydrogen ions to move from ECF to ICF
- Hydrogen movement into cell promotes K movement out of cell and into ECF
- Shifted K is lost in urine because of osmotic diuresis
how does DKA lead to death?
buildup of ketoacids in blood or acids can lead to vomiting and fluid loss which results in hypovolemia aka shock which leads to renal failure. the retention of ketones and glucose makes the metabolic acidosis even worse which will result in comatose from dehydration, electrolyte imbalance and acidosis = DEATH
what are patients most likely to die of from DKA?
DYING FROM LOW POTASSIUM LEVELS INSTEAD OF HYPOVOLEMIA
what are clinical manifestations of DKA?
1) polyuria (frequent urination) and polydipsia (frequent thirst)
2) orthostatic hypotension
3) kussmauls respiration ; sweet fruity odour due to high level of ketones in blood
how do you access weight in DKA?
Skin turgor
what are the lab findings
1) blood glucose > 14mmol/L
2) ABG pH < 7.35
3) Serum HCO3 < 15mmol/L
4) Anion Gap > 12 mmol/L
5) Ketones in the blood and urine
6) Glucosuria
what is anion gap and how do we find it?
Anion gap is the difference between the measured serum cations and anions in ECF
- helps determine the source of acidosis
what is the normal anion gap range?
8 -16 mmol/L
define the relationship between anion gap and metabolic acidosis?
anion gap increases in metabolic acidosis associated with acid gain.
NOTE: normal anion gap from metabolic acidosis associated with bicarbonate loss
