Lab Med 105-120 verified Flashcards
What does prothrombin time assess?
Hepatic dysfunction, specifically function of the extrinsic blood coagulation cascade
What does the long ACTH stimulation test indicate - Rise above upper limit?
= no primary adrenal insufficiency
What does the short ACTH stimulation test indicate?
If cortisol rises within 30 min = normal
If no rise = need long test
What drugs can cause euthyroid hyperthyroxinemia?
Birth control heroin methadone flurouracil clofibrate
What drugs can cause euthyroid hypothyroxinemia?
“DIP GrandPA”
Dopamine agonists Iodine Phenytoin Glucocorticoids Propranolol Amiodarone
What happens in cyclosporine toxicity? Treatment?
Renal toxicity
Discontinue
What happens to amino acids in cirrhosis and hepatitis (inflammatory diseases)?
Blood levels rise due to impaired hepatic handling –> increases aminoaciduria
What happens to amino acids in severe liver necrosis?
Aminoaciduria surpasses solubility and crystals form
Leucine forms “spheres” (think Lucifer, Lucisphere)
Tyrosine forms “rosettes” (think tyROS = rosette)
What is a disadvantage to the low dose dexamethasone suppression test?
Some false negatives (but less false positives than overnight)
What is a disadvantage to the short (overnight) dexamethasone suppression test, and what conditions exacerbate these disadvantages?
Can present false positives with psychiatric disease, stress, phenytoin
What is a positive anti-microsomal antibody titer indicative of?
Autoimmune disease (Hashimoto's or Grave's) Due to binding with TPO
What is a positive anti-thyroglobulin titer indicative of?
Autoimmune disease (Hashimoto’s - in early hyperthyroiditic state or Grave’s)
What is abciximab?
A monoclonal antibody to IIb/IIIa to block platelet plug formation
How can ACTH measurement determine the cause of Cushing’s dz?
high = Pit adenoma or Ectopic
low (neg feedback) = Adrenal adenoma/carcinoma
What is alpha-fetoprotein?
Tumor-associated protein
