Monitoring Diabetes Mellitus Flashcards
Goal of blood glucose monitoring
Maintain glucose within target range
Immediate benefit of blood glucose monitoring
Identify, treatment and prevention of highs and lows
Long term benefit of blood glucose monitoring
Prevention of long term complications
Challenge
Getting correct result every time
Point of care test is
Any test performed on patient out side the laboratory
Point of care test advantages
Faster stabilisation of threatening crises
Immediate result
Small sample volume
Better compliance
Reduce length of hospital stay
Reduce repeat visits
Better control of disease
POCT results in
Way shorter waiting times
POCT disadvantage
Analytical performance can be inferior to lab
Cost is higher than lab
Risk of poor operator competence
Risk of poor quality patient information
Risk of poor equipment maintenance
Capillary glucose testing?
Often- decided by treatment
Test - for self management
More frequent test is associated with better control
Measuring plasma glucose is
More accurate but must go to lab
Difference between whole blood and plasma glucose
Whole blood glucose is q9-15% lower than plasma
POCT results are converted to
Plasma equivalent
Normal glucose % in urine
0.1%
Also small amount during pregnancy
Urine glucose disadvantages
Test is retrospective
Hydration affected results
Not diagnositic
Urine dipstick test disadvantage
Visual reading is subjective
Long term control of blood glucose
Glycated haemoglobin ( measure of glucose over 1-3 months)
Serum fructosamine (mean glucose control over 2 preceding weeks)
Glycated haemoglobin
HBA1C- addition of glucose to N terminal valine of B chain of HB
Advantages of using HBA1C
Standardised
No patient preparation
Not influenced by stress
Small biological variation
Disadvantage of HBA1C
Expensive
Increases with age misleading if anaemia or renal failure
Ethnicity
Situations in which HbAqc must not be used
HbA1c reflects glycaemia over the preceding 2 – 3 months so may not be raised if blood glucose levels have risen rapidly All symptomatic children and young people Symptoms suggesting Type 1 diabetes (any age) Short duration diabetes symptoms Patients at high risk of diabetes who are acutely ill Taking medication that may cause rapid glucose rise e.g. corticosteroids, antipsychotics Acute pancreatic damage/pancreatic surgery
What can interfere with HBA1C
Haemoglobin variants
Anaemia
Chemicallly altered hb (carbamylation/ acylation)
Reduced glycated not process
Ketone measured in
Blood
Ketones measured how
Boood test for hydroxybutyrate
Define microalbuminuria
24 hour collection- 30-300 mg/24hr
Microalbuminuuria can be detected by
Not urine dipstick test
Diagnosis of microalbuminuria cannnot be made
In presence of an acute metabolic crisis and patients should not be screened during inter current illness
Ideal glucose monitoring device
Minimally invasive/ non invasive
Continuous sensing
Continuous glucose monitoring how
Subcutaneous implanted enzyme electrode
Continuous glucose monitoring measures what
Glucose in the tissue
Lags behind blood glucose 5-15 minutes
Advantages of cg
Frequency of testing
Viewing of trends
Less need for finger sticks
Disadvantages of cgm
Safety- implanted sensor designed to be used for short amount of time
Efficiency and accuracy - can be rejected by immune system initially
Expensive
