urinalysis - synovial fluid

synovial fluid

viscous liquid found in the joint cavities, has viscosity of an egg white

movable joints

synovial fluid is found in the cavities of _____

hyaluronic acid

synoviocytes in synovial membrane secrete_____ that makes the fluid viscous

noninflammatory arthritis

degenerative, osteoarthritis; wear and tear that happens with age

inflammatory arthritis

immune system damages healthy tissues of joints, things like lupus, RA, ankylosing spondylitis, lyme disease, etc

septic arthritis

bacteria or fungi invade joint space triggering inflammatory response

septic arthritis

children: usually from organism in blood spreading to joints or trauma, S. Aureus and streptococcus are common

septic arthritis

adults: most cases are associated with IV drug use or STIs, N. gonorrhea, MRSA, pseudomonas, and e. coli are common

hemorrhagic arthritis

an accumulation of blood in the joint can be caused by an injury to the joint, cancer, hemophilia, and other health conditions

arthrocentesis

needle aspiration to collect synovial fluid

3.5 mL

normal amount of synovial fluid in the knee

sterile heparinized or SPS

tube for microbiology collection

liquid EDTA

tube for hematology collection

sodium fluoride

tube for glucose collection

clear and pale yellow

normal color of synovial fluid

deeper yellow

color seen with noninflammatory and inflammatory effusions

green tinge

color seen with infection

red

color seen with hemorrhagic or traumatic tap

milky

clarity that is crystal induced

turbid

clarity that is from WBCs or cellular debris or fibrin

hyaluronic acid

polymerization of _____ makes fluid viscous

polymerization

arthritis decreases _____

mucin clot test

add 2-5% acetic acid to form a clot, and if it clots then it is not synovial fluid?

normal saline/methylene blue

what should be used to dilute the sample for WBC counting?

hyaluronidase

what does the sample need to be incubated with before doing a differential count?

neutrophils

<25% in synovial fluid, increase in sepsis

lymphocytes

<15% in synovial fluid, increase in noninflammatory

reiter cells/neutrophages

vacuolates macrophages with ingested neutrophils

ragocytes (RA cells)

neutrophils with small, dark granules containing RA factor

lipid droplets

seen in crush injuries

hemosiderin

pigmented vilonudular synovitis

monosodium urate (MSU)

crystals seen in gout

calcium pyrophosphate dihydrate (CPPD)

crystals seen in pseudogout

monosodium urate (MSU)

impaired purine metabolism, high purine foods, alcohol, fructose, leukemia, chemo, decreased renal excretion of uric acid

calcium pyrophosphate dihydrate (CPPD)

degenerative arthritis, disorders causing elevated calcium levels

compensated polarizing light microscope

what is the microscope used for crystal identification

polarizing light

a contrast enhancing technique that improves the quality of the image obtained with birefringent materials when compared to other techniques such as darkfield and brightfield microscopy

MSU crystals

these have a bright strong birefringence and the long axis will be yellow against the red background when parallel to the axis of slow vibration; needle shaped

CPPD crystal

usually will be less birefringent and is blue in the direction of the arrow; rod/needle shaped

glucose

decreased levels seen in inflammatory and infectious/septic arthritis, patient needs to fast for 8 hours before

total protein

increased in inflammatory and hemorrhagic arthritis

uric acid

elevation indicates gout, measured as a first evaluation

lactate

increased in septic arthritis caused by gram positive cocci and gram negative bacilli, >9 indicates bacterial arthritis

alkaline phosphatase, GGT, LDH, AST

enzymes in synovial fluid that are tested to monitor rheumatoid arthritis

chocolate agar

culture must be done on _____

RA and LE

the most common autoimmune causes of arthritis

lyme disease

arthritis is a frequent complication of this, test for burrelia burgdorferi antibodies