Endocrinology diagnostic techniques Flashcards
(11 cards)
What is the purpose of tests?
Added information to complete jigsaw; to decide whether to accept or exclude a particular diagnosis
After a patient has been referred, what must you do?
Take history then
Clinical physical examination
What is the pre-test probability? How is guaged?
Probability of patient having a disorder before a diagnostic test is carried out.
Gauged by history and examination findings
What are the options for diagnostic testing? What is the procedure in endocrinology?
Do blood tests BEFORE imaging as imaging can give false positives.
Better to get biochemistry first
What is a static blood test?
Snap shot in time of hormone (chemical) levels in patients when the blood test was taken
E.g. ACTH, cortisol, sodium, potassium
What are the factors to take into account when carrying out static blood tests?
Time of day- Circadian cycle secretion
Pulsatility- many hormones secreted in pulses. If taken after pulse, reading will be low. If taken during pulse, reading is high.
What are the 2 ways of performing a DYNAMIC blood test?
Give example
Suppression test- if you think patient has too much hormone
Stimulation test- if too low ; e.g.synACTHen
What are the limitations with dynamic tests?
Logistics; staff, cost
Patient acceptability
Safety- insulin tolerance test
Interpretation- how low is low in suppression test and high in stimulation
How do you interpret endocrine results?
Look at pre-test probability and see if pre -test probability statement is concordant with test results
Sometimes they are not concordant
What happens if pre-test probability and results are not concordant?
Troubleshoot
What are the ways of troubleshooting?
Look at patient again; condition change over time
Look at pre-test probability again; INTERPRET he result in this context
Look at logistics of test; i.e wrong patient and time of day, lab error, pulsatility. Maybe not handled properly
If still difficult; repeat the test.
