Urinalysis and Body Fluid Analysis Exam 2

what is commercial urinalysis systems

standardizing urine microscopes by controlling techniques used to prepare and view sediment

what is the recommended volume to centrifuge

400 to 450 g for 5 minutes to obtain sediment is 12 mL

what are the aspects of viewing and reporting formats

laboratory procedure needs to be followed exactly

same microscope should be used for all microscopic and if not possible then diameters of field of view must be identical on all

urine components assessed using at least 10 low power fields or 10 high power fields depending on specific component

what are the staining techniques

supravital stains to enhance visualization

acetic acids bring out nuclear detail of WBCs and lyses RBCs

fat stains such as sudan 3 or oil red 0 identify fats inside cells or free floating

supravital stains to enhance visualization

what has to be done to cholesterol since it does not stain

must be confirmed with polarizing microscopy

characteristics of supravital stains

most common in crystal-violet and safranin

what is toludine

stains various cell components differently to help id the cell

what does acetic acids bring out

nuclear detail of WBC and lyses RBC

what is gram stain

used to identify bacteria and yeast

rarely used in urinalysis

what is prussian blue

stains iron in hemosiderin granules blue

can be free floating or inside cells

what is hansel stain

methylene blue and eosin-Y

for id of eosinophils

what is brightfiled microscope technique

most commonly used

what is phase contrast

ideal for urine sediments

allows more detailed visualization of translucent or low-refractile components and living cells

what is polarizing

confirms presence of cholesterol, which forms a Maltese cross pattern with polarized light

also used on crystals

what is interference contrast

gives 3-d images but high cost prevents use by most labs

what are formed elements

originate throughout urinary tract or contamination

not all formed elements indicate an abnormal or pathologic process

presence of large numbers of abnormal formed elements is diagnostically significant

technologist must be familiar with normal ranges of each component

characteristics or red blood cells

small biconcave disks (aprox 8 um in diameters and 3 um deep)

can also be crenated distorted or ghost cells

viewed and enumerated on high power

normally RBCs in healthy adults are less than or equal to 3 per hpf

what does increased RBCs mean

along with RBC casts-renal bleeding

no casts or protein-bleeding below the kidney or caused by contamination

what does a positive strip test for blood mean

no RBCs seen

RBCs lysed: released hemoglobin tests positive

false-positive tests-detects myoglobin per oxidases

what does a negative strip test for blood mean

RBCs seen

ascorbic acid interference causes false-neg result

RBC look-alikes present such as yeast or crystals

Characteristics of white blood cells

any type of WBC from blood can be found in urine

viewed and enumerated on at least 10 hpf

WBCs in healthy adults usually less than or equal to 8 WBC/hpf

since WBCs are motile they can enter urinary tract at any point

characteristics of WBCs

WBCs casts are evidence of an upper urinary tract infection as are cellular casts and coarsely granular casts

increased WBCs but no cellular casts and no cellular casts and no or low level of protein are evidence of lower urinary tract infection

what are the discrepancies between WBCs and leukocyte esterase test

WBCs tend to lyse but would still be positive for leukocyte esterase

lymphocytes do not contain LE

may not be WBCs but look-alikes such as renal tubular epithelial cells and at times even RBCs

what is the clinical significance of white blood cells

increased WBCs in urine termed leukocyturia

inflammatory urinary tract conditions and almost all renal diseases show increased WBCs particularly neutrophils

eosinophiluria is a good predictor of acute interstitial nephritis due to drug sensitivity, usually for penicillian and its derivatives

lymphocyturia seen in kidney transplant rejection

characteristics of epithelial cells

some epithelial in urine result from normal cell turnover of again cells; others represent damage and sloughing from inflammation or disease

large numbers of some epithelial can indicate improperly collected urine and other indicate a severe pathologic process

characteristics of squamous cells

most common and largest, use low power

live entire urethra in female; distal portion in males

rarely significant; usually from contamination

characteristics of transitional cells

live renal calyces, pelvis, ureters and bladder

vary in size due to separate layers

seen in urinary tract infection, urinary procedures carcinoma

characteristics of renal tubular cells

each portion of tubule lined with different types of cell

convoluted tubular and collecting duct cells enurmerated

seen in acute ischemic or toxic renal tubular disease from heavy metals or drug toxicity

characteristics of casts

formed in distal and collecting tubules with a core matrix of uromodulin secreted by renal tubular cells

cylindrical thick in middle parallel sides

sizes and shapes vary

acid pH, increased solutes, urine stasis, and increased albumin enhance cast formation

a few hyaline or finally granular casts normal; increased numbers and other types seen in renal disease, extreme exercise and diuretics

types of casts

hyaline, waxy, WBC, RBC, renal tubular cell, mixed cell, granular, fatty, bacterial, others

characteristics of crystals

can form in urine on standing

significant in freshly voided urine

identified by microscopic appearance and pH

some indicate a pathologic process

what are the factors influencing crystal formation

concentration of urine solute

urine pH

slow flow of urine through tubules

types of crystals

amorphous urates, acid urates, monosodium urate, drugs, uric acid, calcium oxalate, bilirubin, cystine, cholesterol

what are the four types of renal diseases

glomerular-most often immure mediated

tubular-result from toxic or infectious substances

interstitial-result from toxic or infectious substances

vascular-caused by a reduction in renal perfusion that induces morphologic and functional changes in kidney

characteristics of glomerular diseases

diseases that damage glomeruli include immunologic, metabolic and hereditary

characteristics of secondary glomerular diseases

systemic diseases that initially and principally involve other organs but also affect kidneys

characteristics of primary glomerular diseases

specifically affect kindeys often only organ involved

primary diseases consist of several different types of glomerulonephritis

what is cellular proliferation

increased numbers of capillary endothelial, nesangial, and epithelial cells in glomerular tuft

what is leukocyte infiltration

neutrophils and macrophages attracted by a local chemotactic response

what is glomerular basement thickening

any process that results in enlargement of basement membrane (immune complexes and diabetes)

what is hyalinization with sclerosis

accumulation of homogenous eosinophilic extracellular material

what are the clinical features of glomerular diseases

hematuria (blood in urine)

proteinuria (protein in urine)

oliguria (limited output)

azotemia (elevated levels of urea and other nitrogen compounds in blood)

edema

hypertension

what is nephrotic syndrome

group of clinical features that occur simultaneously

heavy proteinuria

hypoproteinemia

hyperlipidemia

lipiduria

edema

urine microscopic

what is systemic lupus erythematosus

autoimmune disorder with immume complex deposits and complement activation

what is diabetes mellitus

carbohydrate metabolism disorder leads to glomerular syndrome, hypertension, susceptibility to pyelonephritis

what is amyloidosis

systemic disease involving many organs; characterized by deposits of amyloid, a pathologic protein substance

leading to proteinuria and nephrotic syndrome

what is acute tubular necrosis

ischemic ATN - seen in sepsis, shock, trauma

toxic ATN - from exogenous or endogenous nephrotoxins

what are the types of tubular dysfunction

fanconi’s syndrome

cystinosis and cystinuria

renal glucosuria

renal phosphaturia

renal tubular acidosis

what are tubulointerstitial disease/infections

urinary tract infections

acute pyelonephritis

chronic pyelonephritis

acute interstitial nephritis

yeast infections

what is acute renal failure

sudden decrease in glomerular filtration rate, azotemia, and oliguria

functional abnormality but no cellular changes

classified as prerenal, renal and postrenal

what is chronic renal failure

progressive loss of renal function

due to hypertrophy or remaining healthy nephrons, not clinically recognizable until 80% function lost

azotemia, acid-base imbalance, abnormal calcium and phosphate metabolism

what is renal calculi

aggregates of mineral salts in a matrix of proteins and lipids

75% of renal calculi contain calcium

found primarily in renal calyces, renal pelvis, ureters, or bladder

absence of natural inhibitors postulated cause

what are the 4 factors that influence calculi formation

Supersaturation of clerical salts in urine

optimal urinary pH

urinary stasis

nucleation or original crystal formation

what are amino acid metabolism disorders

cystinosis and cystinuria

maple syrup urine disease

phenylketonuria

alkaptonuria

tyrosinuria

melanuria

what is diabetes mellitus

problems with glucose metabolism

one long-term side effect is glomerular damage and chronic renal failure

what is diabetes insipidus

decreased antidiuretic hormone or nephrons are resistant to ADH

results in polyuria

what is prophyrias

herditary defects of heme synthesis pathway

increased porphyrins and porphyrin precursors in blood and urine

what are heel stick blood samples are used

neonates are used to screen for inherited metabolic disorders

what is tandem mass spectrometry

the analytical detection method used to scree for the substances produced in the many metabolic disorders