Ch 13&14 POCT and common labs; professionalism and ethics

CLIA clinical laboratory improvement amendments

Standard of US labs
Methods and machines maintained and accurate

CLIA waived vs regulated

Waived performed in office; regulated sent to lab

CLIA waived examples

POCT
Pregnancy (beta-hCG)
Glucose
Urinalysis
Lipids (Cholestech)
cardiocheck

CLIA regulated examples

CBC
ABG

PBS peripheral blood smear

Manually count and observe morphology of blood w microscope

Blood surface antigens

A
B
+ (rh)

Universal donor

O-

Universal acceptor

AB+

ABG

asses ventilation, oxygenation, and acid-base balance
Check condition of critically I’ll pts, diagnose electrolyte imbalances, monitor O2 flow rates
*never CLIA waived

Gram negative

Stain red
Single peptidoglycan layer

Gram positive

Stain crystal violet
Thick peptidoglycan and teichoic acids

Gram stain steps

Dye (crystal violet)
Mordant (grams iodine)
Decolorizer (ethanol/acetone)
Counterstain (safranin)

Smear

Mono layer of organisms showing characteristic arrangements
Universal precautions employed

Function of kidneys

Remove metabolic waste from blood, maintain acid base balance, regulate hydration
Produce hormones like renin (bp) and erythropoietin (rbc)

urea

Nitrogenous product of protein metabolism

First morning sample

Concentrated specimen
Clean catch or midstream
Common for routine UA

Midstream specimen

Best representation of bladder contents
At least 25ml

Clean catch specimen

Clearest, most accurate results
Clean external genitalia

Healthy urine composition

96% water and 4% dissolved substances (urea, NaCl, sulfates, phosphates)
1200-1500ml/day

Physical examination of urine

Volume
Color/appearance
Temperature
Odor
Specific gravity

Chemical examination of urine

pH
Glucose
Ketone
Protein
Blood
Bilirubin
Urobilinogen
Nitrite
Leukocyte esterase

Microscopic examination of urine

Observe sédiment from 10-15ml centrifuged

Urine specific gravity

Ratio of weight to volume compared to DI water
Measures kidneys ability to concentrate and dilute, can be an indication of renal disease or hormone deficiency
Normal: 1.015-1.025

Urinary pH

4.5-8
Healthiest ~6

Glycosuria

Glucose in urine
Diabetes mellites (also polyuria and thirst)
Test relies on glucose oxidase, copper rxn used for conformation

Urinary leukocytes

Indicate bacteriuria or UTI
Test for leukocyte esterase (purple)
Clean catch midstream

Urinary bacteria

Positive nitrites indicate, also UTI

Hemoccult

Detects hidden blood in stool

Throat culture

Detect bacteria, fungi, or viruses in throat

Quality control

Ensure accuracy

Standard

Substance of known value

Proficiency testing systems

Agencies that check accuracy

Hematology lab

Lab that deals w Components of blood (wbc, rbc, platelets)
CBC most common, also reticulocyte count, sedimentation rate and red cell indices
Coagulation frequency

Chemistry lab

Electrophoresis: chemical components of blood based on charge
Toxicology: plasma levels of drugs and poisons
Immunochemistry: radio immunoassay (RIA) and enzyme immunoassay to analyze hormones, enzymes, and drugs
Profiles and panals

Profile

Group of tests ordered to asses status of organ or system

Panal

Set of tests commonly ordered together

Serology/immunology lab

Immune response through antibody production
Serum

Microbiology lab

Culture and sensitivity (C&S) to identify microorganisms

Blood bank lab

Collect, store, and prepare blood for transplant
Separated into packed cells, platelets, fresh frozen plasma, cryopecipitate

ABO inheritance pattern

Codominance