Urinalysis Module 1

Ch.1,3,4

osmolality

determined by using freezing point depression

PAH test

measures renal blood flow and tubular secretion

the normal serum osmolarity is

275 to 300 mOsm

Biological hazards

Infectious agents (bacterial,fungal,viral, parasitic infections)

Sharps hazard

needles, lancets, broken glass (cuts,punctures,exposure to blood borne pathogens)

Chemical hazards

toxic, carcinogenic, caustic agents

Radioactive hazards

Equipment, radioisotopes (exposure to radiation)

Electrical hazard

ungrounded, wet equipment, frayed cords (burns/shock)

Explosives/Fire hazards

Open flames, organic chemicals (burns, dismemberment)

Physical hazards

wet floors, heavy boxes, patients (falls, sprains, strains)

PASS

Pull, Aim, Squeeze, Sweep

Standard precautions

measures taken in healthcare setting to prevent spread of infection btwn yourself from patients

Universal precautions

steps taken to prevent the spread of disease through body fluids from everyone

Specimen rejection

unlabled containers, contaminated specimens, insufficient quantity, improperly transported, not correctly preserved

Pre-examination

specimen collection, handling, storage

examination

test performance, instrument maintenance, requirements personnel

Post examination

report results (electronically, telephoning) in timely manner & to appropriate healthcare provider.

Quality Management

Process to guarantee quality patient care (quality system)

Post-exposure prophylaxis (PEP)

medical treatment started after exposed to pathogen to prevent infection

Turn around time (TAT)

Total amount of the time required to obtain or collect a specimen, prepare the specimen, perform testing, and report the results.

Urinalysis

the examination of urine to determine the presence of abnormal elements

Formation fo urine (4 processes)

1.renal blood flow, 2.glomerular filtration, 3.tubular reabsorption, 4.tubular secretion

Renal Blood flow (nephron)

1. renal artery, 2. afferent arteriole, 3. glomerulus, 4. efferent arteriole, 5. peritubular capillaries (proximal tubule), 6. vasa recta, Peritubular capillaries (distal tubule), 7. Renal vein

urinary system functions

removes waste products, activates vitamin D, regulates blood pressure (RAAS), acid/base balance, secretes erythropoiten, regulates fluid/ electrolytes

Urine composition

95% water and 5% solutes

Organic solutes: urea, creatine, uric acid

Inorganic: chloride, sodium, potassium

Quality Assessment

continued monitoring of testing process

What is RAAS?

system that regulates blood flow to glomerulus and responds to changes in blood pressure

RAAS in order

Low BP/plasma sodium, Renin secretion, Angiotensin 1, Angiotensin 2, vasoconstriction, proximal convoluted tubule (sodium reabsorption), aldosterone, distal convoluted tubule (sodium reabsorption), ADH, collecting duct (H2O reabsorption)

Glomerular filtration

non selective filtration, hydrostatic and oncotic pressure & RAAS

Tubular secretion

Blood to Urine, Removes H+ ions (acid/base balance), proximal tubule

Tubular Reabsorption

Urine returning to Blood, proximal tubule, affected by CC mechanism and ADH

CC (countercurrent) mechanism

Reabsorption of H2O from tubular secretion. Descending Limb (permeable- H2O is out), Ascending limb (impermeable- H2O kept in)

diabetes mellitus

increased Specific gravity, increased glucose, decreases insulin

Diabetes Insipidus

decreased specific gravity, decreased ADH

juxtaglomerular apparatus

regulation of arteriole size, maintains constant glomerular BP

Low systemic BP

larger afferent, smaller efferent, prevents decreased glomerular blood flow

High systemic BP

smaller afferent arteriole, prevents over filtration and glomerular damage.

Normal blood PH

7.4

Normal Daily urine output

1200 mL

Oliguria

decrease in urine output

Nocturia

increased urine excretion at night

polyuria

increase in daily urine output

Specimen collection

wear gloves, leak proof containers, disposable, wide mouth, flat bottom, screw caps, 50 mL capacity

specimen labeling

patients name, ID #, date, time, age location, healthcare provider name, place on container;NOT lid

Specimen handling

test within 2 hrs of collection, refrigerate or chemically preserve if testing is late, most problems are caused by bacterial growth

specimen preservation

refrigerate at 2 to 8 celcius: decreases bacterial growth and metabolism. must be at room temp. for chemical preservation.

bactericidal chemical/ boric is most common

Random specimen

is most common/ frequently collected

first-morning specimen

most concentrated, used for orthostatic protein confirmation and urine pregnancy tests

glucose tolerance specimens

collected at the same intervals as blood samples, results correlated with renal threshold for glucose

24 hr specimen

carefully timed specimen, patient must be instructed when to collect, should be kept refrigerated or in ice,

catheterized specimen

collected from hollow tube, most common test is bacterial culture

mid-stream clean catch specimen

safe, less traumatic, less contaminated than routine specimen, provide with antiseptic towlettes, sterile container, and instructions

suprapubic aspirations

external introduction of needle for aspiration from the bladder; Most sterile specimen collected.

drug specimen collection requires what document?

Chain of custody: documentation from the time of specimen collection until time of receipt of lab results.

creatinine clearnace calculations

C=UV(ml/min)/P

eGFR clearance test

90-130 mL/min is the range

secretion of renin is stimulated by

mucula densa cells

bicarbonate ions combine with

combine with hydrogen ions to regulate pH

MDRD-IDSM variables

age, gender, race

asked for both routine urinalysis and a culture

culture is performed first

Sodium hypochlorite

a disinfectant for decontamination of blood and body fluids

Centrifuging an uncapped specimen may produce a

biological hazard in the form of

aerosols

system used by firefighters to assess the risk potential

RACE (rescue, alert, contain, evacuate)

what steps are taken when the results of reagent strip QC are outside the stated confidence limits?

check expiration date of reagent strip, run a new control, open a new reagent strips container