Diabetes Flashcards
Diagnosis of Diabetic ketoacidosis
Ketoanemia > 3.0mmol/L
CBG > 11.0mmol/L or known diabetes mellitus
HCO3 < 15.0mmol/L
Venous pH < 7.3
Symptoms of diabetic ketoacidosis
Polyuria
Polydipsia (increased thirst)
Blurred vision
Weakness
Headache
Orthostatic hypotension
Tachycardia
GI symptoms
Fruity breath from acetone production
Hyperglycaemic hyperosmolar state
Marked hyperglycaemia > 30.0 mmol/L
Severe dehydration (Hypovolemia)
Osmolality usually 320mosmol/kg or more
DKA management
- Rehydration
- IV insulin 0.1ml/hr/kg
- Continue long acting insulin
- Correct electrolyte abnormalities
- VTE prophylaxis
- Avoid hypoglycaemia
HHS management
Calculate osmolality (2Na + Glucose + Urea)
- IV 0.9% NaCl
- Switch to 0.45%NaCl if osmolality not declining
- Commence IV insulin (0.05ml/kg/hr) if CBG not falling with IV fluids alone
- Prophylactic anticoagulation is required in most patients
Metformin mechanism
Increases insulin sensitivity and uptake by skeletal muscles. Suppresses hepatic glucose production. Renal excretion.
Metformin pros and cons
Pros:
- Helps weight loss
- Doesn’t cause hypoglycaemia
Cons:
- GI upset
- Lactic acidosis
Cautions with metformin
Not to be used in severe renal impairment and use with caution in moderate impairment.
Hold in AKI - risk of lactic acidosis
Caution in hepatic impairment - risk of lactate accumulation
Sulphonyl ureas mechanism
Stimulates pancreatic insulin secretion by blocking K+ channels in pancreatic beta cells
Gliclazide
Pros and cons of sulphonylureas
Pros:
- Good reduction in HbA1c
Cons:
- Weight gain
- Insulin resistance
- GI upset
- Hypersensitivity reactions
Cautions with sulphonyureas
Can cause hypoglycaemia
Increased risk in elderly, pituitary and adrenal insufficiency
Dipeptidyl peptidase 4 inhibitor mechanism of action
Delays inactivation of GLP-1.
GLP-1 increases insulin secretion after a meal and reduces glucagon release.
GLIPTINS
Pros and cons of DPP4 inhibitors
Pros:
- Low hypoglycaemic risk
- No effect on weight
- Well tolerated
Cons:
- URTI
- Headache
- Nausea
- Heart failure
- Hypersensitivity and skin reactions
Cautions with DPP4i
Increased risk of urticaria, pancreatitis, angioedema
Can be used in CKD with dose titration
Sodium glucose transporter protein 2 mechanism of action
Inhibits renal reabsorption of glucose. Insulin independent mechanism.
FLOZIN
Pros and cons of SGLT2 inhibitors
Pros:
- Low risk of hypoglycaemia
- Weight loss
- Can improve blood pressure
Cons:
- Increased UTIs especially in women
- Diabetic ketoacidosis
Cautions with SGLT2 inhibitors
Avoid in CKD
Avoid with diuretics
Thiazolidinediones mechanism of action
Potentiates insulin action and enhances its effects on skeletal muscles, adipose tissue and liver with increased glucose uptake and reduced hepatic gluconeogenesis.
PIOGLITAZONE
Pros and cons of thiazolidinediones
Pros:
- Low risk of hypoglycaemia
- Reduced insulin resistance
Cons:
- Weight gain
- Peripheral oedema
Cautions with pioglitazone
CI in heart failure and fracture risk
Caution in hepatic impairment
Glucagon like peptide mechanism
Increases insulin secretion after meals from beta cells and suppresses alpha cells from releasing glucagon.
Reduces gastric emptying and improves satiety.
Exenatide, Liraglutide
Pros and cons of GLP-1 agonists
Pros:
- Weight loss
- Low hypoglycaemia risk
Cons:
- GI upset
Cautions with GLP-1 agonists
Injectables not suitable for all patients
Possible association with gallstones
1st line (monotherapy) for DM
Start metformin when HbA1c rises above 48mmol/L (6.5%) on lifestyle intervention.
- If GI adverse effects, switch to MR metformin
2nd line (dual therapy) for DM
Start dual therapy when HbA1c rises to 58mmol/L
- Metformin + DPP4i
- Metformin + Pioglitazone
- Metformin + Sulphonylurea
- Metformin + SGLT2 inhibitor
3rd line (triple therapy) for DM
Start if HbA1c remains 58mmol/L
- Metformin + DPP4i + sulphonylurea
- Metformin + Pioglitazone + sulphonylurea
- Metformin + Pioglitazone + SGLT2i
- Metformin + Sulphonylurea + SGLT2i
If this treatment fails, start insulin treatment and aim for HbA1c to reach 53mmol/L
