Flashcards in Diabetes Deck (15)
Describe the mechanism behind DKA?
Lack of insulin results in decrease cellular uptake of glucose.
There is then a decrease production of pyruvate by glycolysis so fat metabolism has to take over.
This leads to an increased in the production of ketones.
There is increased glucose --> hyperglycaemia and glycosuria --> osmotic diuresis --> fluid and electrolytes lost
There is increased ketones --> acidosis --> vomiting --> fluid and electrolyte lost
The fluid and electrolyte loss leads to impaired renal function and then impaired excretion of ketones and hydrogen ions, increasing the ketone acidosis.
How do you diagnosis DKA?
Acidosis, hyperglycaemia, ketosis (main ketone is acetoacetate)
How do you manage DKA?
1L stat, then 1L over 1hr, 1L over 2 hrs, 1L over 4 hrs and 1L over 6hrs
When BM is 30ml/hr
0.1units/kg/hr - approx. 6units/hr
continue until ketones stop
Treat any underlying infections
Give LMW heparin until mobile
Change to SC insulin when eating and drinking
What are the diagnostic criteria for diabetes?
Symptoms of hyperglycaemia + fasting BM >7 or random BM > 11.1
Raised BMs on two occasions, fasting BM > 7, random BM > 11.1 or oral glucose tolerance test 2hr value >11.1
Other than autoimmune what are the causes of diabetes?
STEROIDS, anti HIV drugs, antipsychotics, thiazides
Pancreatitis, surgery to pancreas, trauma, haemochromotosis or CF, pancreatic cancer
Cushings, acromeglay, phaeo, hyperthyroidism, pregnancy
How do you diagnose impaired glucose tolerance?
fasting BM 7.8 but
How do you diagnose impaired fasting glucose?
Fasting BM >6.1 but
Drugs in diabetes - how do they work?
Glucoagon like peptide analogue
alpha glucosidase inhibitors
Metformin - increases insulin sensitivity
Sulfonylurea (glicazide) - increased insulin secretion
Insulin - directly reduced blood sugar
Glitazone (pioglitazone) - increases insulin sensitivity
GLP analogues (exenatide) - augments insulin
acarbose - decreases breakdown of starch
How much does 1 unit of insulin reduce the blood glucose by?
1 unit reduces by 2-3mmol/L
What is the difference in onset, peak and duration of actrapid and novorapid?
Actrapid has a 1 hour onset, peaks in 2 hours and has a 6 hour duration
Novorapid has a 15-30min onset, peaks in 1 hour and has a 4 hour duration
When someone is having a hypo what do you need to give them?
100mls lucozade, 15g of glucose powder or glucose juice, 100mls of 20% dextrose
1mg of glucagon IM if unable to swallow - only works if there is sugar stored in the liver, so cant give twice in succession or if the patient has had a hypo recently.
In DKA what is the main blood ketone?
How much insulin do you give someone in HHS?
0.05units/kg/hr and only start once the BM has stopped falling from fluids alone
What are the problems with lowering the glucose to fast?
cerebral oedema, central pontin myelinolysis