Clin Chem exam 4

Total Bili

0.3-1.2 mg/dL

hsTroponin

< 34 ng/L

hsCRP

> 3.0 mg/L

TSH > 20 years

0.55-4.78 uIU/L

Cortisol AM

5.27 - 22.45 ug/dL

Used to detect inflammatory disease like sepsis

CRP

Used for assessing risk of developing CVD

hs-CRP

Cardiac hormone secreted by ventricles when the heart wall stretches

BNP

BNP increased in the following: (CMVR)

CHF, Myocardial ischemia w/o necrosis, heart valve disease, renal failure

Used to confirm dx of CHF in acute settings

BNP

unstable plaque rupture, thromboses, and arterial occlusion

Unstable angina

WHO criteria for diagnosing AMI

clinical symptomology

characteristic ECG changes

rise of cardiac markers

2/3

Characteristics of ideal cardiac marker (5)

specific

rise soon after MI

high for several days

correlated w patient outcome

24/7

CV for Cardiac Biomarkers at elevated concentrations should be less than

10%

Increases an hour after MI, returns to normal after 12-24 hours

Myoglobin

Useful as a marker for reinfarction early after initial event

Myoglobin

Rises 3-4 h post MI, falls normal after 48-72 hrs

CK-MB

Useful for reinfarction after initial rise and fall

CK-MB

More cardiac specific than CK-MB

Troponin T and I

Rise 3-12 hours, peak 12-24, and remain elevated for over a weak

Cardiac Troponin

How to rule out ACS from PE?

D-Dimer - > 90% of PE pts have increased D-dimer

Increased fecal and urine urobilinogen, no unconjugated bilirubin in the urine

prehepatic jaundice

gallstones, cancer, or blockage causing increased bilirubin in circulation, with NO fecal or urine urobilinogen

Posthepatic jaundice

what is delta bilirubin

Excess Bc that is albumin bound

How does Bc and Bu react differently with diazo acid reagent?

Conjugated can react directly (already soluble)

Unconjugated requires an additional reagent or accelerator

Bili specimen requirements

No hemolysis, no sunlight

Tests for hepatic function (ATDIP)

Albumin, T bili, D bili, INR/PT

Tests for hepatic damage (4)

ALT, AST, ALP, GGT

General method for determining hormones

SENSITIVE immunoassay using serum or urine specimens

Adenohypophysis

Anterior lobe

Neurohypophysis

Posterior Lobe

Posterior Pituitary released hormones

Oxytocin

ADH

Hormone regulated by positive feedback

Oxytocin

Released during cervical stretching and baby suckling

Oxytocin

Oxytocin is produced by the ____

hypothalamus

ADH is produced by the _____

hypothalamus

Stimulated by increased plasma osmolality and decreased BP

ADH

Stimulated renal tubular reabsorption of water and vasoconstriction

ADH

Two forms of ADH deficiency

Diabetes insipidus

Psychogenic polydipsia

Diabetes sees ____ serum osmolality and sodium

NORMAL

PD sees _____ serum osmol and sodium

low unless access to water is restricted

Direct Anterior pituitary hormones

GH and prolactin

Tropic Anterior Pituitary Hormones (4)

TSH, LH, FSH, ACTH

GH stimulates release of ____

IGF-1 from the liver

How does IGF-1 compare to insulin?

Alike in structure, but opposite in effect as it is a biological amplifier of GH

Released in response to exercise, stress, hypoglycemia

GH

Inhibited by somatostatin from HP

GH

GH governs growth of ____, while IGF-1 governs growth of ______

skeleton, internal organs

GH suppression test

give oral glucose load

GH should decrease

GH stimulation test

Insulin tolerance test

Normally increase in GH

Causes for prolactin excess (4, DHSP)

decreased dopamine inhibition (antipsychotics, antidepressants)

Hypothyroidism

Pituitary stalk defect

Prolactinoma

Symptoms of prolactin excess (HILHO)

hypogonadism, impotence, decreased libido, headache, osteoporosis

Thyroid prohormone with some biological activity

T4

Active thyroid hormone

T3

Inactive hormone that converts in placenta, fetal tissue, and brain

rT3

How do thyroid hormones perform transcriptional mediation?

Free hormone crosses membrane, with assistance from membrane transport proteins, and internal receptor is present on DNA

Concentration of binding proteins impacts ____ but not _____ hormone concentrations

TOTAL but not FREE

Pregnancy, estrogen, acute hepatitis, oral contraceptives are all cause for _____ thyroid binding proteins

Increased thyroid binding proteins

Chronic liver disease, malnutrition, TBG deficiency, acromegaly, androgens, glucocorticoid are signs of _______ thyroid binding proteins

decreased thyroid binding proteins

remember low transthyretin (low pre-albumin) = malnutrition marker

Key tests for thyroid function (3)

TSH, FT4, thyroid abys

Recommended screening test for thyroid disease or disorder

TSH

Second line test for thyroid function test

Free T4

Most useful in determining hyperthyroidism

Total T3

Autoimmune hypothyroidism

Hashimotos

Low FT4, High TSH

Hypothyroid Primary disorder

Low FT4, Low TSH

Hypothyroid secondary, pituitary disorder

heat intolerance, tremors, tachycardia, thyroid storms

Hyperthyroidism

Autoimmune hyperthyroidism

Graves disease

High FT4, Low TSH

hyperthyroid primary disorder

High FT4, High TSH

Hyperthyroid pituitary disorder

Abnormal thyroid tests observed in critically ill patients

Euthyroid sick syndrome

Testosterone Transport Fractions

2-3% Free

30% Albumin

65% Sex hormone binding globulin

Free + Albumin-bound testosterone =

bioavailable test

Analytical method for testosterone

Immunoassay

Preferred specimen for testosterone IA

AM serum

Major source of androgens

Adrenal glands

Low Test, High LH/FSH

Testicular disease

Low test, Low LH/FSH

Pituitary Disease

Hypothalamic low testosterone

GnRH deficiency (Kallmann syndrome)

3 Estrogens

Estrone (E1)

Estradiol (E2)

Estriol (E3)

Major and most potent estrogen

Estradiol / E2

Major estrogen produced by placenta

Estriol (E3)

Estrogen transports

2-3% Free

97% sex hormone binding globulin

Preps uterus for implantation, regulates menstrual cycle and maintains pregnancy

Progesterone

Sources of progesterone

Corpus luteum, adrenal glands, and placenta

Progesterone transport

2-10% Free

90% Cortisol binding globulin

Used to confirm ovulation and evaluate risk of early miscarriage

Progesterone

Estradiol and progesterone are measured by ____ using ____ sample

immunoassay, serum

Causes of Low estradiol, high LH/FSH (MDO)

Menopause, gonadal dysgenesis, premature ovarian failure

Causes of low estradiol, low LH/FSH (2) (D,Pr)

Pituitary destruction, hyperprolactinemia (suppression of GnRH)

Hypothalamic lesion causing GnRH deficiency leads to: (Female)

Low Estradiol, Low LH/FSH

McCune-Albright Syndrome

Abnormal bone development, early puberty, spontaneous ovarian hyperfunction

Days / Phases of menstrual cycle

Day 1 = menstruation

14 days = follicular

1 day = ovulation

12-16 days = luteal

When does LH fall in menstrual cycle?

Ovulation when follicle ruptures and releases ova

What does the follicle develop into after ovulation?

Corpus luteum to produce progesterone

Phase in which progesterone increases to maintain endometrium

Luteal Phase

E2 inhibits ____

FSH/LH

If no fertilization occurs in the luteal phase:

E2 and progesterone fall

If fertilization occurs in the luteal phase

hCG is produced, which maintains progesterone production by corpus luteum until placenta developed enough to take over

Synthesized by trophoblastic cells of the placenta

hCG