Endocrine diagnostics Flashcards
What should you do if you suspect someone has an endocrine condition?
1-Assess patient first-take history and do physical examination 2-Then decide what endocrine diagnostics tests would be helpful to confirm/refute diagnosis
Why wouldn’t you just use tests on patients to confirm an endocrine problem with a patient you don’t know?
because doing tests e.g blood tests, are never going to give an answer they are just another piece of supporting/ non supportive evidence for a diagnosis -Also tests must be used and interpreted in the clinical CONTEXT -meaning shouldn’t do them without first meeting the patient, knowing their story and then examining him as it would be difficult to analyse blood results
What is a pre test probability?
the probability of a patient having the disorder before a diagnostic test -do the test if you think the probability is high to help support your diagnosis
How can you choose the right test?
Ask yourself that if you do this test if it will CHANGE the way you manage a patient
What test is best for endocrine diagnosing?
Get blood tests done first and only if they are guiding you in a particular direction should you then get imaging e.g. MRI
What is a static blood test?
snap shot in time of hormone levels in the patients when the blood test was taken
If you think there is something wrong with a patients adrenals what blood tests should you ask for?
-Cortisol, ACTH, sodium, postassium
If a patient is seen in a clinic at 4pm should the patient have the blood tests that afternoon or come back another day for 8/9am blood tests
The patient needs to come back first thing in the morning because -mant hormones are secreted according to a 24 hour circadian cycle so if you measure hormones at the wrong time of day the hormone could appear low -you don’t know if this is normal or a true reflection so the results cant be interpreted =pointless
What factors should you take into consideration when doing a static blood test?
PULSITILITY-many hormones are secreted in pulses=at a certain point hormone levels can be very high so if you took the test at the wrong time you could get a result that is difficult to explain
What test should you do if you think a patient has too much of a hormone?
-do a SUPPRESSION test that tries to suppress that hormone -and if the test cannot suppress the hormone = hormone levels are high
What test should you do if you suspect a patient has too little of a hormone?
-Do a STIMULATION TEST -which stimlates the body to produce that hormone tp see if the gland responds normally and secretes the hormone
What are dynamic blood tests?
-suppression/stimulation tests -take multiple blood tests at different times
What factors should you take into account when taking a dynamic blood test?
Patient acceptability-some tests take a long time so patients might have to spend the whole day in hospital Logistics- staff, hospital visit cost, staff cost safety-e.g in the insulin tolerance test high insulin dose is given making patient hypoglycaemic which is a stimulus to see if the pituitary responds appropriately by releasing cortisol and growth hormone BUT this can be dangerous Interpretation- How low is low in a suppression test and how high is high in a stimulation test
How would we test if someone had low cortisol levels?
Inject synthetic ACTH and see if adrenals respond appropriately by producing If he doesn’t produce cortisol it supports your theory
What should you do if your pre test probability suggested the patient didn’t have the condition but the test results did? OR that the pre test probability suggested that the patient does have the condition but the tests did not ?
Troubleshoot
