Lab Med Final

urine analysis

dip stick and microscopy(presence of five bacteria per high power field means there is an infection and you have to get a culture)

can be used to detect infection, urolithiasis, malignancy, or metabolic disease

also get urine culture and susceptibility

-Complicated UTI

-High-Risk Populations: symptomatic males, pregnancy, females 65+ years old

-Immunocompromised

-Recurrent Infections

-Treatment Failure or Resistance

-Preparation for endoscopic urologic procedures

types of urine specimens

• For urine culture and sensitivity: must use clean catch- midstream, sterile container, cleanse urinary meatus with antiseptic. And area cleansed beforehand

• random urine specimen: choice for drug screen does not require clean catch or any prep and can be obtained any time of the day

• 24hr urine: large container that is quantitative study for hormone, glucose, and proteins (nephrotic syndrome for Cr clearance

• first morning viod: they viod before bed and then collect the first pee of the day - best for STI testing

urine analysis

includes a urine dip stick and a microscopic exam

drip stick: pH, specific gravity, glucose, bilirubin, nitrates, protein, ketones, acult blood, more affordable (absences of nitrate does not eliminate need for culture bur presence means there an infection)

microscopy- small volume to identify cells - bacteria, crystal, cast present, quantitative(not just yes and no)

both needed: urine having intact RBC and hemoglobin will both be detected by dip stick and microscopy would confirm true hematuria (RBC in urine)

color and transparency

normal- clear to deep yellow

red- bleeding

dark yellow/orange- bilirubinemia

cloudy- pus, RBC, bacteria

specific gravity

high means more concentration could mean dehydration or glucose in urine

low = dilated urine

indication of hydration

pH

high protein diet = lower pH -affected by diet

can indicate kidney stone

shows excretion of acid by metbolic acitivity

blood

detects the presence of hemoglobin and myoglobin, UTI, cancer, nephrolithiasis- false + in myoglobinuria (rhabdo and muscle disorder)

detect peroxidase activity of urinary tract

glucose

is + if blood glucose is above 180 mg/dL as in diabetes

ketones

increase fat metabolism due to low carbs, starvation, vomiting, diabetic ketoacidosis

nitrites

• due to bacteria converting nitrates to nitrites (gram -) but not all bacteria does that conversion so does not r/o UTO. E.coli need four hours to convert so if pt is frequently peeing may be false neg

leukocyte esterase

produced by WBC breakdown sign of use UTI

•False positive due to vaginal discharge or menstrual blood, some medications (ex: doxycycline), systemic infections

•False negative due to dilute urine, high level proteinuria or glucosuria, expired test strips

used with nitrites (nitrites is more specific while esterase is more sensitive )

bilirubin

present with liver diseasep

proteins

will not pick all protein but very sensitive to albumin and a sign of renal disease can also be with exercise, seizure, pre-eclampsia

urobilinogen

•present in very low amounts

•Increased with hemolysis,  intestinal bacteria

produced from break down of bilirubin in intestine

Combining diagnostic value

•Ruling In: The presence of blood on a dipstick, especially when combined with positive nitrites, has a high predictive value for UTI.

•Ruling Out: While individual negative results are not definitive, the combination of negative LE, negative nitrites, and negative blood is highly effective for eliminating a UTI from the differential diagnosis

leukocyte enterase is produced by

neutrophiles

urine microscopy quantitatively of

cells

cast

crystal

bacteria or yest

if drip stick shows blood cound RBC

if shows nitrites check WBC

crystal

form when mineral in urine precipitate dependent on urine pH and concentration

indicate renal stone

helpful in gout- uric acid crystals

cast

form in renal tubules

•Clumps of material or cells that form in the renal tubules; take on shape of tubules

•Ex: WBC cast in Pyelonephritis

•Ex: RBC casts in glomerulonephritis

urine microalbumin

test for albumin- Prescence nephropathy detectable before GFR goes down

also use to monitor kidney and dietetic monitoring

an increase in microalbumin in diabetics have a higher risk of cardiovascular event, renal disease, retinopathy - should be monitor yearly with diabetics and hypertension

even for non diabetics elevated urine microalbumin correlates to lower life expectancy due to CVD

spot urine albumin/creatine ratio

quantifies the amount of albumin in urine- measures extend of glumonlar damage - therefore the development of kidney disease

1+ or greater= injury to glomeruli

urine electrolytes

•Quantitative measure of electrolyte content of urine (Calcium, Sodium, Potassium)

•Variable clinical utility (ex: Urine sodium aids in diagnostic eval of hyponatremia)

urine drug test

qualitative:•Amphetamines

•Barbiturates

•Cocaine

•Marijuana (THC)

•MDMA

•Methadone

•Opiates

•Oxycodone

where is lect 17

acute phase reactants

proteins whose plasma concentration increase/ decrease 25%during inflammatory stress

levels reflect the Prescence and intensity of the inflammatory process

IL-6 inducer of most APR other IF Y, TNF, IL1 - negative APR like albumin and ferratin

most common are ESR/ CRP

Eythrocyte sedimentation rate ESR

EBC suspended in plasma fall when place in a vertical tube good at measuring fibrinogen non specific can also be impacted in changes in RBC size, shape, number and tequnical factors

•infection, inflammation, advanced neoplasm, tissue necrosis, or infarction with these condition: RBC have more fibrinogen and will fall faster '

helpful: monitoring disease courses for autoimmune

ESR limination

very nonspecific influence by many factors any tissue injury, increase protein levels, anemia , smoking/ obesity, pregnancy, specimen handling, age (increase with age),

C- reactive protein (CRP)

an acute phase reaction - better than ESR levels rise and fall faster

nonspecific for infection, inflammation, and tissue necrosis

preferred for detecting early inflammatory responses

protein produced by the liver during an acute inflammatory process

good for cardiovascular and connective tissue disorders

more sensitive for rapidly responding indicator of inflammation- measuring only one protein while ERS is an accumulation

good parker for future cardiovascular event (plaque have inflammation markers)

4-6 hrs when it rise

could mean bacterial, MI, inflammatory response- mainly reserved for cardiovascular screening than general inflammatory

limitations of a CRP/ ESR

can have false positive so only use when there is clinical susception

ANA

•ANA = type of autoantibody that targets substances inside the nucleus of cells (nuclear antigens). 

•Most commonly used to screen for autoimmune diseases; especially connective tissue disease

•Sensitivity variable depending on disease

•Specificity= low

•Clinical Context is KEY– pretest probability is important

•Higher pretest probability of autoimmune disease, the more value ANA has

-high sensitivity or lupus (good for r/o) also present in viral infection hismatoos, scleroderma,

order when high test probability

reported as a titer and pattern (lower titers are often insignificant with no sx of signs of autoimmune diease)

ANA and RF

both antibody test

ANA-lupus

RF- RA

RA

inflammation joint destruction and deformities

RA the antibody that is created against the synovial joints

symmetric polyarthritis, morning stiffness, extraarticular manifestation

abnormal antigenic IgG antibodies, antibodies against Fc portion of antigen IgG produced

RF and ACPA (Anti-citrullinated peptide antibodies (ACPA or anti-ccp) confirm RA diagnosis

RF has lower sensitivity but higher specificity

higher levels of RA= greater likelihood the pt had true rheumatic disease and can correspond to worse prognosis and poor drug responsiveness

serum uric acid

gout testing (hyperuricemia) - monosodium urate crystals that cause joint point

crystal formed from so oversaturation of serum acid

shellfish, anchovies, alc increase uric acid

uric acid levels in gout

can be high, low, or normal during acute flare

how long does it take for resolution of gout flare

2 weeks to completely normalize

what is the goal for urate lowering meds

less than 6mg/dL want to make sure you have the right titration of medications

make sure to wait 2 weeks out from a flare to get serum and make alteration to medications

does a normal serum uric acid level mean you can r/o a flare

no can be in normal range during acute flare

clot byproductions

fibrinogen and d-dimer

D dimer used to identify

intravascular clotting so like a DVT, PE, and disseminated intravascular coagulation (DIC- accelerated clotting, increase platelets, and uncontrollable bleeding)

highly sensitive but no specific good for r/o is high needs imagining for confirmation

advanced age = above 50 age x 10= threshold positive

is there is a high pretest probability for PE or something like that

skip the D-dimer and go directly to imaging

MUST consider the pre-test probability prior to ordering

using the modified well criteria and PERC rule = but do not have to know the criteria

When to not order a D-dimer

when there is a very low risk patient

or

extremely high risk patients that have a high pre test probability they go straight to imaging

all pregnancy test based

on detection of hCG

hCG double every 3 days for the first 6 weeks - then declines after the first trimester

urine HCG

known as point of care

qualitative not quantitative

false neg- testing before levels are detectable

false +

serum HcG

qualitative and quantitative ability to trend the levels

-ensure complete evacuation of products of miscarriage

-serial monitoring demonstrating abnormal low or slowly can suggest ectopic or miscarriage

abnormal high hCG

molar pregnancy

LH from and what it does, why would we check

anterior pituitary gland

acts on either ovaries and testes that stimulates hormone release -used when checking for primary hypogonadism (LH will be high but the hormone will be low)

Leydig cell

Klinefelter syndrome

boys

turner syndrome

increase in FSH/ LH

menopose

FSH will be high cause there is no negative feedback of estrogen

testosterone

best time to take 7

DHEA- testosterone in peripherical fat and some produced in the adrenal and ovaries ?

finish last three

slides

test twice for hypogonsism

HPV

starting at 21 regardless of sexual activity with pap (cytology) every 3 years and after 30 HPV testing every five years

HPV testing is via vaginal swab and does not e