Urinalysis and Body Fluids Exam 1

what is quality assessment

is a program of checks and balances to ensure the quality of a labs services

what does a quality assessment must involve

a mechanism for error detection and provide an opportunity to improve services

what does quality assessment encompasses

preanalytical, analytical and postanalytical;

What are the preanalytical components

ensuring appropriate test ordering processes, specimen collection transport storage and handling, patient education / prep and instructions, procedures for handling inappropriate or unacceptable specimens, documentation of any problems or unusual situations, accurate up to date available procedure manuals, and adequate personnel training and supervision

what are the analytical components

equipment / instrumentation, reagents and supplies, procedure manuals with standardized procedures, analytical methods, monitoring of analytical method/quality control, and laboratory personel tech skills training monitoring technical competence and continuing education

what is equipment/instumentation

requires calibration, preventive maintenance and monitoring and documentation of these actions

what is reagents

use of reagent-grade or analytical-grade reagents. distilled or deionized water and quality monitoring. and verification of newly prepared reagents before use

what is procedure manuals

should be current complete readily available comprehensive, and comply with clinical and laboratory standards institue standards

what is external quality control

measures to monitor and evaluate a labs performance compared with that of other facilities

what are the postanalytical components

procedures that affect results reporting and interpretation

What are biological hazards

transmission - based precautions apply to specific patients w known or suspected infections

what are 3 categories of transmission-based precautions

contact precautions,droplet precautions, airborne precautions

what are 3 routes of infection or disease transmission

inhalation, ingestion, direct inoculation or skin contact

what are chemical hazards

requires each facility to have a chemical hygiene plan defining safety policies and procedures for all hazardous chemicals

what are the purposes of routine urine analysis

aid in disease diagnosis, screen for asymptomatic congenital or hereditary dieases, monitor disease progression, and monitor therapy effectiveness or complications

why study urine

urine is a fluid biopsy of kidney, noninvasive means to evaluate kidney, specimens readily available, urine is ultrafiltrate of plasma

what is first morning specimen

empty bladder at night before going to bed, collect specimen first thing in the morning, most concentrated;often preferred specimen

what is random specimen

for routine screening, can be affected by excess fluid intake or exercise

what is timed specimen

collections for predetermined length of time, collections at a specified time of day

what is routine void

requires no patient preparation, collected by having patient void into appropriate container, patient normally needs no assistance other than clear directions, can be random or first morning specimen

what is mid-stream “clean catch”

for bacterial cultures or to prevent vaginal contamination, requires cleaning supplies, additional instructions to patient and sterile container, requires thorough cleaning and rinsing of glans penis or urethral meatus before collection, begin urination into toliet and collect midstream portion in container

what is catheterized specimen

requires collection by medical personnel, sterile catheter inserted through urethra into bladder, urine flows directly into collection bag, specimen obtained anytime from collection bag

what suprapubic aspiration

requires collection by medical personnel, involved puncturing of abdominal wall and distended bladder by using needle and syringe, sample aspirated directly from bladder, bladder urine normally is sterile

pediatric collections

often commercially available plastic urine collection bags that attach with a hypoallergenic skin adhesive, patients perineal area cleaned prior to bag attachment, specimen removed ASAPre

what are some reasons for speciment rejection

unlabeled or mislabeled specimen, mismatch of specimen name or ID number, inappropriate collection technique for test ordered, not properly preserved or time delay in receipt of specimen, visibly contaminated sample, insufficient volume for tests ordered

what is necessary for containers and labels

clean, dry and made of clear or translucent material with lid to prevent spillage, sterile containers required for cultures, extra-large commercial containers are available for large timed collections, label placed on container not on lid

what changes in unpreserved urine

Decreased urine clarity and increase in oder, possible color changed from solute alteration, false-neg glucose, false-neg ketones, increase in nitrite and pH, disintegration of formed elements

what is needed for preservation of timed collections

require addition of a chemical preservative to maintain integrity of analyte to be tested, kept on ice or refrigerated during collection period, check collection manual to identify necessary preservative, and deliver specimen to lab immediately

what organ is the principal organ for regulating body fluid composition

the kidneys

what is the primary elimination route of soluble metabolic wastes

renal exretion

what is osmolality affected by

affected by solute number, not size or weight

what is final osmolality determined by

determined in distal and collecting tubules when antidiuretic hormone (ADH) is present

what is specific gravity

comparison of density of urine to that of water, depends on number of particles and mass

what is polyuria

greater than 3L/day, ADH secretion inadequate or receptors ineffective

what is oliguria

less than 400mL/day, urinary obstruction, tubular dysfunction, fluid loss

what is anuria

absence or cessation of urine excretion, progressive renal disease or renal failure

what is testing renal concentrating ability

assess tubular re-absorptive function by demonstrating tubules can produce concentrated urine specimen

What are the 3 most prevalent solutes in urine

urea, chloride, sodium

what are fluid deprivation tests

used to differentiate causes of polyuria due to water diuresis, water consumption restricted, if urine is concentrated, test is ended

what happens in “neurogenic” diabetes insipidus

ADH decreased

what happens with “nephrogenic” diabetes insipidus

lack of renal response to ADH

what is glomerular filtration rate

volume of plasma in mL that is completely cleared of a substance per unit of time, C=(UxV)/P

what are clearance tests

tests for GFR use substances removed solely by glomerular filtration (inulin), tests for tubular secretion use substances removed solely by tubular secretion

what is creatinine clearance

creatinine is a waste product of creatine in muscles, produced at a relatively constant rate and excreted by kidneys C= (UxV/p) x (1.73/SA)

What is estimated glomerular filtration rate

effective tool that helps to detect chronic kidney disease, calculation based on serum creatinine level and patients age gender and ethnicity

what is Beta2- Microgobulin

a low-molecular-weight protein found on surface of nucleated cells and sled into plasma, readily passes through glomeruli

what is Beta2-microglobulin used for

indentify early kidney transplant rejection, differentiate tubular and glomerular diseases

what is cystatin C

low-molecular-weight protein that has potential as a marker for long term monitoring of renal function, produced by nucleated cells and filtrered by glomerulus and is catabolized by tubular cells

what does screening for albuminuria do

early detection of low levels of albumin in urine and signals need for additional testing and aggressive intervention

what is p-amino-hippurate clearance test

exogenous nontoxic weak acid secreted almost exclusively by proximal tubules, used as indicator of renal tubular secretory function

what is the measurement of titratable acid vs urinary ammonia test

assess tubular function for removind acids

what is oral ammonia chloride test

give ammonium chloride and measure series of urine pH and plasma bicarbonate, used to diagnose renal tubular acidosis

what is most commonly used tests for evaluating renal function

creatinine clearance for assessment of GFR, urine osmolality for tubular concentrating ability, urine protein electrophoresis to evaluate glomerular permeability to plasma proteins, plasma creatinine, eGFR calculation

where is the glomeruli located

in the outer cortex and is the exclusive site of plamsa filtration

what does the medulla consist of

pyramid shaped tissue, each tissue has a duct that enters a calyx

what do calyxes funnel

funnel urine from collecting tubules to renal pelve

what is the flow of urine

urine from each renal pelvis enters a ureter, urine passes from ureter to bladder (holding area), a nerve reflex signals and urge to urinate at 150mL, contraction of bladder and relaxation of urinary sphincter push urine into urethra leading to outside of the body

what is the glomerulus

an afferent arteriole that supplies blood individually to the glomerulus of each nephron

branches into a capillary tuft on entering

capillaries come back together to form efferent arteriole on exiting

efferent arteriole branches a second time into a capillary plexus

high hydrostatic pressure of afferent arteriole is driving force behind glomerular filtration

what is renin

large amounts of secretory granule containing enzyme renin are present in afferent arteriole of juxtaglomerular apparatus

renin is released in response to decreased arteriole blood pressure or volume, decreased sodium or increased potassium, vascular hemorrhage

renin causes angiotensin formation and aldosterone secretion

aldosterone causes kidneys to retain sodium and water

what is urine formation

180,000 mL of plasma is filtered each day producing a final urine volume of 600 mL to 1800 mL

what does urine formation cosist of

plasma filtration at glomeruli

what roles do the kidneys play an important role in

removal of metabolic wastes

regulation of water and electrolytes

maintenance of body’s acid-base equilibrium

what is glomerular filtration barriers

capillary endothelium with its large open pores

tri-layer basement membrane

filtration diaphragms located between podocutes of bowman’s space

what is glomerular filtration

selectivity of barrier based on molecular size and charge allowing water and small molecules to pass rapidly

endothelium has a negative charge that large molecules have to overcome to pass

what is tubular transport

reabsoprtion and secretion mechanisms are some, differing only in direction of movement

tubular transport mechanisms are active or passive

each solute has a specific transport system that may differ by area of tubule where it occurs

what is reabsorption and secretion

tubules selectively reabsorb substances necessary for body homeostasis and function

does not reabsorb waste products such as creative

why does secretion occur

eliminate wastes and substances not normally present in plasma

adhust acid-base status of body

what are the 3 body systems involved in maintenance of pH

blood bicarbonate buffer system

pulmonary system

renal system

how does the blood bicarbonate buffer system maintain pH

buffers prevent pH from changing

how does the pulmonary system maintain pH

lungs can exhale or retain carbon dioxide (an acid)

how does the renal system maintian pH

increase or decrease of excretion of hydrogen ions

increase or decrease of formation of ammonia

increase of decrease of reabsorption of bicarbonate

what is antidiuretic hormone

controls water reabsorption in collecting tubule

ADH is produced in hypothalamus but released into blood from posterior pituitary gland

causes a change in tubule epithelium and increase in water reabsorption occurs

release of ADH controlled by negative feedback with arterial blood pressure and positive feedback with plasma osmolality

what is the normal color of urine

yellow due to urochrome

how does urochrome make urine yellow

is a lipid-soluble pigment in plasma excreted in urine at a constant rate

what are the substances that change urine color

blood or myoglobin

bilirubin

porphyrins

melanin

indican

homogenetisic acid

ingested substances

foam in urine

not normally included on report forms

normal urine when shaken will produce white foam but dissolved

stable white foam indicates large amounts of albumin in urine

yellow foam caused by increased bilirubin

clarity characteristics of urine

describes cloudiness or urine caused by suspended particulate matter that scatters light

normal specimens are clear

what are the causes of cloudiness

contamination of dissolved solutes

red blood cells white blood cells epithelial cells clots bacterium and casts

characteristics of odor in urine

normal urine has an order

urine on standing becomes odorous due to bacterial conversion of urea to ammonia

ingestion of certain foods or drugs

what are some metabolic disorders that changes the odor of urine

ketone produce sweet or fruity smell

amino acid disorders often produce odd odors

what are characteristics of urine

concentration is the amount of solutes present in volume of water excreted

urine normally consists of 94% water

solute types vary with patients diet, physical activity, and health

dilute urine has fewer solute particles per volume of urine

what is specific gravity

an expression of concentration

ratio of urine density to density of an equal volume of pure water under standard conditions

SG= density of urine / density of equal volume of pure water

what is refractoretry

indirect method based on refractive index of light

when light passes from air into a solution at an angle it refracts and slows direction of beam

ratio of light refraction in 2 differing media called refractive index

as number of solutes increase light velocity decrease and light angle decreases

what are the 3 factors that affect the refractive index of a solution

wavelength of light used

temperature of solution

concentration of solution

what are the advantages of refracoretry

small sample size

automatic temp compensations

in viewing field distinct edge between light and dark areas making readin SG easy

what is the reagent strip method

indirect colorimetric estimation of urine density based on amount of ionic or charges solutes present

non-ionic solutes such as glucose, urea, protein or radiographic media are not measured

only method that eliminates effect of nonionic large-molecular-weight solutes on SG

what is osmolality

concentration of a solution expressed in terms of osmoles of solute particles per kg of water

what is the principal uses of osmolality

evaluate renal concentrating ability of kidneys

monitor renal disease

monitor fluid and electrolyte balance

differentially diagnose cause of polyuria

what is freezing point osmometry

able to detect presence of volatile solutes

accurate results even with lipemic samples

what is vapor pressure osmometry

small sample size but inability to measure volatile solutes

indirectly measures decreases in vapor pressure caused by solutes in a sample by measuring decrease in dew point temperature

what is isosthemuria

inability of kidneys to change specific gravity of plasma ultrafiltratew

what is polyuria

Excretion of greater than 3L/day

what is oliguria

Excretion of less than 400 mL/day

what is anuria

complete lack of urine excretion