Laboratory Dianostics Flashcards
Bx, bi
Biopsy
CBC
Complete blood count
C&S
Culture and sensitivity
DNA
Deoxyribonucleic acid
EEG
Electroencephalogram
FBS
Fasting blood sugar
H&H, H/H
Hemoglobin and hematocrit
HCG
Human chorionic gonadotropin
POCT
Point of care testing
Pap
Papanicolaou test
PH
Potential hydrogen
QRS
Ventricular deplorazation
STAT
Immediately
STD
Sexual transmitted disease
TC
Throat culture
UA
Urinalysis
UC
Urine culture
U
Unit
MU
Milliunit
Standard universal precautions
- treat all blood and body fluid as infection
- use personal protective equipment: sterile/non sterile gloves, lab coat, shoes cover, gown
- protect patient from you, yourself from patients
- use special care to avoid injury from sharp instrument/equipment
- never use needles, other sharps unnecessarily
- dispose of sharp in puncture/leak proof containers
- report all accidental contaminated sharp injuries to supervisor
Environmental safety
- employee training in workplace hazard is supplied
- employer accidental exposure plan must be in place
- each hazardous substance must be identified with hazardous label: display name of contained material, list effects of chemical
- material safety data sheet used for hazardous agents
- all puncture proof sharp container, biohazard bag, eyewash station must be correctly labeled
Quality control
- specimen collected for pathological testing in formalin preservative
- microbiological culture, treat sterilely, do not expose to formalin
- give pt verbal/written procedure performance instruction, confirm pt understands
- employee get lab procedure training every year
Quality maintenance
- check expiration date: collection container, tube, swab, reagents
- calibrate lab instruments, each recorded in quality control log, perform on set of standards alone, verify every 6 months
- standard is specimen like one you would normally process
- perform/document control test each day
- control sample used 1st every time pt sample is processed
- positive/negative control samples used with test yield a quantitative test response
- other control sample show results fall within normal range, sample use to test that give quantitative test results
- when testing, adhere to procedure design to identify problems with equip calibration, errors in test procedure, defective test supplies
- perform/ document equip maintenance: clean, adjust, part replacement
Microscope
Essential component of lab illuminates/magnifies specimens, to view/analyzed. Shouldn’t be moved around unless necessary. If must move, grasp arm, support weight with base
Light source
Microscope
-built in light bulb located under center of stage
Ocular lens/biocular
Eye piece of microscope
- located at top
- magnifies field of view 10 times
Objective
Contains magnifying lens
- located center of microscope just above stage, mounted on swivel base
- the two are dry
- dry lens magnification are 10x (lower), 40x (high)
- one is oil immersed, 100x
Stage
- Prepared slide placed here, held in place with metal clips
- opening allows light passage to prepared slide
Condenser
- on sub stage, it directs, focus light through slide
- can be raised or lowered
Iris
Diaphragm
- located within condenser
- can be opened/closed to regulate intensity of light passing through condenser
Microscope objective maginification
- low power: 10x used for-urine sediment for cast/epithelial cells, scan blood smears
- high power: 40x used-wet preparation: urine sediment for RBC, WBC, bacteria, yeast, parasite
- oil immersion: 100x used-microorganism, blood films: blood cell morphology, count, WBC differential
Microbiology
Study of minute unicellular, multicellular, acellular organism
- includes area of bacteriology, virology, mycology, parasitology
- most microorganism live on body: normal flora
- small number are pathogenic in body falls in category of infectious disease
Microorganism
5 major groups: bacteria, fungi, algae, Protozoa, virus
-normally found everywhere: in food, water, air, soil, skin, within body
Morphology
Study of form/structure of organism, the special features specific to it
Normal flora
Microorganism found on skin/within body, normally do not cause disease
-some beneficial to body, they destroy potentially harmful microorganism within intestinal tract
Pathogens
Microorganism cause disease
-infectious agent capable of transmitted from 1 living being to another, which they grow and multiply, cause infection without sign of disease
Virulence
Capacity of microorganisms cause illness
For example: HIV
Bacteria
Single-cell organism: prokaryote, consider vegetable matter
-antibiotic affective lay fight/control bacterial infection
Aerobes
- 1 way bacteria is identified
- condition which thrive
- Require oxygen to survive
Anaerobes
2 way bacteria identified
Bacteria thrive without oxygen, some die if exposed too oxygen
Morphology
Form and shape of organism
Cocci
Form/shape of organism:
Round
Singular: coccus
Disease: pneumonia, streptococcal throat, gonorrhea
Bacilli
Shape/form of organism: rod-shaped
Singular: bacillus
-disease: tuberculosis, tetanus, urinary tract infection, whooping cough
Spirilla
Shape/form: spiral
Singular: spirillum
-disease: syphillis, Lyme disease
Staphylo
- form/shape: grapelike clusters
- methicillin-resistant staphylococcus aureus (MRSA), resistant to antibiotic, most often occur in people who are hospitalized, health care setting
- if acquired in hospital: nosocomial infection
Form of bacteria
- May have spores:hard-shelled formation, resistant to heat, disinfectants, making difficult to kill
- some have flagellae: projection enable movement
- bacteria arrangement: chain=strepto-, pairs=diplo-, clusters=staphylo-
- pattern of reproduction: colony appearance/patterns as grown on culture medium
Staining for bacteria smear
- use to identify bacteria, most often with gram stain
- gram-positive: purple-botulism, diphtheria, pneumonia, rheumatic fever, staphylococcal infection, tetanus, streptococcal throat
- gram negative: pink-gonorrhea, meningitis, UTI, cholera, pertussis, plague, thyroid fever, dysentery
- acid fast stain: may be use if gram staining does not stain specimen sufficiently
Fungi
- fungus
- single cell organism, larger than bacteria
- fungal infection may produce in heart, lung, skin, hair, nails, other organs
- resistant to antibiotic
Mold
Multicellular fungi produces spores
- important species of mold: penicillium
- first penicillin developed this mold
Tinea
Fungal skin infection
- athlete’s foot
- ringworm
- thrush (oral
Tinea pedis
Athlete’s foot
Parasites
- live on or in another organism
- use organism for nourishment, growth, reproduction
- host is harmed as parasite thrives
- infection caused by parasite: infestation
- most parasites identified in microscopic exam of urine, feces, tissue fluids, biopsies
Type of parasites
- helminths (worm): roundworm, whipworms, tapeworm, pinworm
- insect: spread viral, bacteria, Protozoa disease
- mosquitoes, ticks, lice, mites
- single cell Protozoa: cause malaria, dysentery
Viruses
- smallest living organism, can only be seen in a microscope
- simpler life form than cell
- can live only within living cell
- relies on host cell to grow, produce, then invade more host cells
- most virus treated only for symptoms
- antibiotic is ineffective treatment, host must endure until it runs it course
Blood borne viral infection
- disease live in host blood.
- transmitted from host to host by contact with infected body fluid, blood, blood products, mucous membranes
- others if have trace of blood in them: vomitus, urine, sputum, feces, perspiration, tears, saliva, nasal secretion
Hepatitis A (HAV)
Acute infective
-transmitted by fecal or oral contamination
Hepatitis B (HBV)
Most common
Infection transmitted by contaminated serum, plasma, needle, entry through all entry portals
Hepatitis C (HCV)
Transmitted by blood transfusion, needle sharing
Hepatitis D (HDV)
Delta hepatitis
- occur in patient with hep B
- transmitted by mucosal contact, needle sharing, sexual contact
Hepatitis E (HEV)
- acute
- occur mostly outside of U.S.
- transmitted by fecally, contaminated water or food
Human immunodeficiency virus (HIV)
- Transmitted acutely: blood to blood, sexual contact modes of transmission
- may be present in all body fluids
- of those infected, 70% will progress into acquired immunodeficiency syndrome (AIDS)
Stages of HIV
- stage 1: acute HIV infection, patient becomes a carrier
- stage 2: asymptomatic latency (may be years)
- stage 3: AIDS related complex (ARC)
- final stage: AIDS- may have kaposi’s sarcoma (cancerous skin lesion), pneumocystis carinii (severe pneumonia), patient has no immunity
Before collection
- verify patient identity (name, DOB)
- review requisition slip, confirm patient proper test preparation
- assemble needed collection equipment, supplies
- wash hands before/after
- wear gloves
- site cleansed with alcohol, spiral technique inside to out, allow to air dry or with sterile gauze
- use sterile collection containers/equipment
After collection
- label container with patient name, date, time, specimen source, your initials
- use biohazard label bag or puncture proof container to dispose all hazardous waste
- incubate culture plates with agar side up, so moister droplets will not fall on growing surface
Handling collection
- Store specimen according to instruction: refrigerate, separate blood components
- avoid contaminating specimen or oneself
- transport disease causing microorganism use agar as a medium to ensure nutrition for microorganism
Urinalysis
- Provide more information about general condition of body than any other tests.
- kidney filters 1,000 L of blood a day, average adult produce 1,250 mL/day
- composed 95% water, 5% waste product
- usually sterile, does not contain bacteria or infection-causing organism
Urine collection
- must be tested as soon as possible
- if unrefrigerated: test well mixed specimen within 1 hour
- if refrigerated: wait until specimen at room temp, no more than 2 hours
Random urine collection
Most common sample type, use for routine screening, collection of 3 oz or more
First morning urine collection
Highest solute concentration, used in pregnancy test for human chorionic gonadotropin, has highest specific gravity
Fasting urine collection
Second morning collection, must for diabetic monitoring
Clean-catch midstream urine collection
Best for bacterial cultures/cultural & sensitivity test
- analyze for type of bacteria/identifies best antibiotic to use
- inside container kept sterile, free as possible of bacteria surrounding urethra
24 hour urine collection
- for quantities analysis
- study of calcium, potassium, creatinine, urea nitrogen, protein, lead levels
- begun after first morning void
Cauterization urine collection
- collected if patient cannot urinate normally
- performed if specimen must be completely sterile
Physical exam urine analysis
- color: pale straw - dark amber
- clarity: rate from transparent - turbid
- specific gravity: density measurement compared to distilled water: normal range: 1.005-1.030, measure by urinometer, refractometer, on Reagan strip
- odor: fruity-diabetes, foul odor- infection, ammonia scent-high concentration of bacteria from sitting in room temperature
Urinalysis color indicator
- colorless: drink excessive amount of water
- red: blackberry, cranberry, beet consumption, blood
- neon yellow: b complex vitamin, excess riboflavin
- orange: pyridium - drug to treat bladder infection
- dark yellow: dehydration, early sign of liver problem
- brown: bean, rhubarb comsumption, old disintegrated blood clots
- blue: methylene blue (drug ingredient for bladder spasm/discomfort
Reagent pads
- located on strips, dipped in urine
- pad react by changing colors
- measurement taken timed
PH scale reagent pad
measure follows:
- normal range: 4.5-8
- pH of 7 neutral
- pH above 7 alkaline
- pH below 7 acidic
Albumin reagent pad
Protein
-result indicate: UTI, kidney disease, vigorous exercise
Bilirubin reagent pad
Degenerated RBC
-results indicate: points of liver damage, obstructive jaundice, hepatitis
Blood reagent pad
Result indicate: kidney damage, UTI, severe burns, muscle injury, menstrual period
Ketone bodies reagent pad
- acetone
- result indicate: fat diet, severe diabetes mellitus, starvation, dehydration, exposure to cold, excessive exercise
Glucose reagent pad
Possible diabetes mellitus if above renal threshold
Nitrate reagent pad
Result indicate: pathogen pretense (UTI), false positive if specimen left out more than 2 hours
-bacteria creat nitrite in vivo
Urobilinogen reagent pad
Converted bilirubin
-result indicate: point of heart disease, liver disease, hemolytic anemia
Microscope exam
- not CLIA waived
- finding should correlate with physical and chemical analyses
- procedure: after centrifuging, pour off supernatant, set up wet mount to examine urine sediment, unstaffed sediments best viewed using high power, low light
Epithelial cells in urine
Come from genitourinary tract
-renal tubular cells
—morphology: round, large nucleus. High number indicate tubular damage or acute infection
-transitional cells:
—morphology: round to oval, may have tail. High number indicate bladder disease or renal pelvis disease
-squamous cell:
—morphology: large, flat, irregular cells. High number indicate vaginal contamination in women
RBC in urine
Normal: 0-2 cells seen using high power field
- morphology: may be round, colorless, from hemolysis
- increase number indicate bleeding somewhere along urinary tract
WBC in urine
Normal: 0-5 cells seen HPF
-increase number indicate inflammation of genitourinary tract
Crystals in urine
-common in all urine specimens, especially if allowed to cool
-type/number vary with pH of urine
-not usually clinically significant unless found in large numbers
-abnormal urine crystals: possible cause are disease state, inherited metabolic disorder, medication, treatment
—cystine (six sided) indicate calculi/congenital defect, can cause mental retardation
—uric acid indicate gout
—cholesterol indicate severe UTI
Mucus threads in urine
Normally present in small amounts
-long wavy threads/pointed ends
Spermatozoa in urine
Common both men and women
Bacteria in urine
Should not normally exist in urinary tract
-more than a few indicate specimens contamination or UTI
Parasites in urine
-
Yeast in urine
indicate diabetic patient/vaginal contamination cause by candida albicans
Cast in urine
- cylindrical structure formed in lumen of nephrons tubules within kidney
- made up of hardened material within lumen are flushed out into urine, indicate disease condition
- counted under low power field, low light, identified under HPF
Hyaline cast in urine
Pale, colorless cylinder with round edges
-indicate kidney disease or normal for heavy exercise
Granular cast
Either coarse/finely granular in appearance
-indicate heavy proteinuria, acute/chronic renal disease, congestive heart failure
Cellular cast
Named for organized structures they contain
WBC casts
Indicate pyelonephritis (chronic renal disease)
RBC casts
Indicate pathological condition
-acute glomerulonephritis, lupus nephritis, severe nephritis
Renal tubular epithelial cast
Indicate ischemia
Waxy cast
Indicate severe renal disease
Hematology
Analysis of blood
- blood content examine/tested give general health information, to identify disease causing organism
- MA may perform blood cell morphology exam, cell counts, various chemical analyses
Serum
Sample blood collected in tube without additive
- once collected, left standing in upright position at room temp for 10-30 minutes allow clot to form
- watery portion of blood contains antibodies, does not contain any clotting factors
- mostly for blood chemistry test, pregnancy test, viral studies, HIV antibodies
Whole blood
Collected in tube with anticoagulant additive
-for hematology test: CBC, coagulation studies, blood glucose, other blood chemistry test
Plasma
Obtain from whole blood collected in tube with anticoagulant additive, then centrifuged
- centrifuged: top layer plasma, middle layer WBC, platelets Buffy layer, bottom layer RBC
- 90% water, 10%: proteins, carbs, fates, amino acids, mineral salt, hormones, enzymes, waste
Plasma
90% water
9% protein
1% fat, carb, gases, waste products, clotting factor, minerals
Formed elements
- erythrocytes: RBC
- leukocytes: WBC
- Thrombocytes: platelets
- cell formed mostly in red bone marrow
Reticulocytes
Newly released RBC from bone marrow, circulates in peripheral blood for 24-36 hours before becomes mature RBC
-normally make up 1% peripheral RBC
White blood cells
5 types, fight infection
- agranulocytes: formed in lymphatic system- lymphocytes, monocytes
- granulocytes: formed in red bone marrow-neutrophils (most numerous), basophils, eosinophils
Neutrophils
- Granulocytes
- 58%-68% of WBC
- Fight bacterial infection : phagocytosis
- primary defense against infection
- segmented nucleus, small granular cytoplasm
Basophils
Granulocytes
- 0%-1% of WBC
- fight allergies
- use phagocytosis
- secrete heparin, histamine, serotonin
- large nucleus, large granular cytoplasm
Eosinophils
- granulocytes
- 2%-4% of WBC
- fight allergies/parasitic infection
- use phagocytosis
- segmented nucleus, large granular cytoplasm
Lymphocytes
Nongranulocytes
- 21%-30% WBC
- produce antibodies to foreign antigens
- backbone of immune system
- large nucleus
Monocytes
Nongranulocytes
- largest WBC
- 4%-8% of WBC
- eliminate dead fragments, dead cells
- use phagocytosis
- produce interferon
- large kidney shaped nucleus
Micropuncture
Finger stick
- use great middle or ring finger of non dominant hand for
- on infants: underside, outer edge of heel
- cleanse with alcohol pad
- allow to dry or wipe with sterile gauze
- puncture should be no deeper than 2.4 mm
- wipe away first droplet of blood, contains more tissue fluid
Venipuncture
- most commonly performed hematological test
- common site: median cubical vein
- other sites: chephalic (thumb side on forearm), basilic vein, back of hand veins
Venipuncture site to avoid
- extensive scar from burns, surgery
- veins subject to numerous punctures
- upper extremity on side of previous mastectomy
- hematoma
- edematous extremities
- intravenous therapy, blood transfusion
- arm with fistula/cannula
Needles
- usual gauge is 19-23
- higher gauge number, higher risk of hemolysis
- butterfly technique: 21-25 gauge-for small veins, geriatric, pediatric, burned patient, patient with limited range of motion, receiving frequent needle sticks
Collection tubes for blood
- adults: 3-10 mL tubes
- children: 2-4 mL tubes
- tube color determined by tube content
Venipuncture steps
- apply tourniquet 3-4 inch above planned puncture site, have patient make fist, palpate for site
- release tourniquet, clean with alcohol pad, allow to dry
- reapply tourniquet
- tourniquet must be release within 1 minute
- anchor vein below site
- enter vein with bevel up 10-15 degrees angle
- release tourniquet when blood flow is established
- use correct order of draw
- gently invert tube 5-10 times to mix collected blood with additives in tube
Yellow or yellow/black
First order of draw
- additive: sodium polyanetholsulfonate
- blood cultures in microbiology, blood bank studies
Red
Second order of draw
- no additive
- serum chemistry study, immunology studies, blood clotting time, blood bank
Red/black: tiger top
Third order of draw
- additive: serum separator tube, clot activator
- serum chemistry studies
Light blue
Fourth order of draw
- additive: sodium citrate
- coagulation Studies
Green top
Fifth order of draw
- additive: sodium heparin, lithium, anticoagulant
- plasma chemistry studies, lithium, ammonia level, arterial blood gases
Lavender, pink
Sixth order of draw
- additive: EDTA, anticoagulant
- whole blood hematology (CBC, WBC), whole blood immunohematology test, lead studies, sedimentation rate
Pale yellow
Seventh order of draw
- additive: acid citrate, dextrose A and B
- HLA tissue typing, paternity test, DNA studies
Gray
Eight order of draw
- additive: potassium oxalate, sodium fluoride, anticoagulants
- glucose studies (GTT, FBS), lactic analysis, blood alcohol levels
Failed attempts
- if 1st attempt to fail to collect specimen, remove needle, try other arm
- if 2nd attempt fails, change needle position, try using another tube, loosen tourniquet
- after 2nd attempt fail, call another experienced phlebotomist for help
Loss of blood flow into tube
- cause by vein collapse
- resecure tourniquet to increase filling
- remove needle to redraw
- reposition needle, may be no longer in vein
Hemolysis
Rupturing of RBC cause release of hemoglobin into blood specimen
-following may be cause: needle gauge too small, shaking collection tube, draw blood begun before alcohol is dry
Hemostasis
Stoppage of bleeding in damage blood vessel
Flash
First appearance of blood drawn into vacuum tube, tube, syringe during venipuncture procedure, gives confidence to phlebotomist
Blood counts
Quantitative study look at total number of blood cells, percentage of each type of cell that makes in entire sample
-CBC, WBC, RBC, WBC differential, platelet count
Blood cell morphology
- Analyze shape, size, grouping of cells
- by creating blood smears
- from fresh blood specimen contain anticoagulant, prepared on glass slide
- spreader slide pull blood thinly on slide
- slide stained to complete preparation, examine under microscope
- perform wbc differential
Hemoglobin
Quantitative analysis of protein in RBC containing iron,
- iron attract, binds oxygens which transported body tissue
- hb main component in RBC
- normal range: men-14-18, women-12-16
Hematocrit
- measure of percentage by volume of RBC in whole blood
- normal: men 42% to 52%, women 37% to 47%
- duplicate hct result should not vary by more than 2% of each other
- layer in centrifuged: hct, plasma, platelet, RBC
- ratio: 3:1 multiply by hb value by 3. Round number to whole number
- formula: hb x 3 = hct +/- 3
Bleeding time
Evaluate blood ability to clot
Normal range 2-7 minutes
Blood typing and ABO antigens
Agglutination points to type of blood
O+
Antigens/antibodies: Rh+ is antigen D, anti-A, anti-B antibodies
- may donate to: O+, A, B, AB
- may receive: O
O-
- no antigens, no antibodies
- universal donor
- may receive from: O-
- rare
A
Most common
- A-antigens, anti-B antibodies
- may donate to: A, AB
- may receive from: A, O
B
B antigens, anti-A antibodies
- may donate to: B, AB
- may receive from: B, O
AB
Rarest blood type
- A, B antigens
- no antibodies
- may donate to: AB
- universal recipient
Rh factor
A, D antigen found on RBC surface
- if RBC contains Rh factor, then it is Rh+ without factor, called Rh-
- if Rh- blood given to Rh+ blood, becomes sensitize, develop anti-Rh antibodies, if same person given Rh+ blood again, anti-Rh antibodies will attack Rh+ blood
- 85% population is Rh+
RhoGAM
Given to Rh- women who just given birth to prevent possible Rh+ blood of newborn from triggering the development of anti-Rh antibodies
- done to ensure 2nd baby, future babies will not develop erythroblastosis fetalis
- can be life threatening to newborn
Erythrocytes sedimentation rate
Rate which RBC settle at bottom of blood specimen
- measure in millimeter per hour
- determine degree of inflammation in body
- wintrobe and westerners method used
Glucose
Chemistry test
Normal range: 70-110 mg/dL
-fasting blood glucose: 12 hour fast, except water, above normal results, glucose tolerance test needed
Glucose tolerance test
Timed
Routine at 6 months of pregnancy
HbA1c
Used to monitor patient with diabetes
- measure amount of glucose lasted hb in blood
- reveals diabetic patient compliance with prescribed diabetes treatment
Carbohydrate metabolism
- to prepare: eats high carb diet for 3 days, fast 8-12 hours before
- may have little water
- first blood draw should be less than 150 mg/dL
- half an hour later, blood and urine drawn each hour as MD prescribes
Cholesterol
- white, waxy, fat like substance essential for normal function of body
- important component of cell membrane
- used in production of hormones and bile
- normal total cholesterol should be less than 200 mg/dL
Low density lipoprotein
Bad cholesterol (LDL)
- should be less than 130 mg/dL
- pick up, carries fat to blood vessels, cause plaque to build up on arterial wall, result atherosclerosis
High density lipoprotein
Good cholesterol (HDL) -remove excess cholesterol from cells, carry it to liver to be excreted
Triglycerides
Blood fat related to risk of heart disease
-should be less than 250 mg/dL
Serology
Immunology
- study of body defense against foreign substance
- study of fluid component of blood, especially measurement reaction between antigens, antibodies within blood serum
- may use urine, body fluids
Antigens
Substance considered foreign by body immune system
- cancer antigen, disease causing microorganism
- cause immune system create antibodies against it
Antibodies
Flow freely through blood, found in blood serum
- measure by titer
- titer measure presence, concentration of substance
Titer
- hormone detection
- used in ABO and Rh blood typing
- assist I’d diagnosis of bacterial, viral disease: duodenal ulcer (helicobacter pylori), infectious mononucleosis (Epstein-Barr virus), Lyme disease, streptococcal (streptococcus progenes), rheumatoid arthritis, human immunodeficiency virus, influenzas virus
Electrocardiogram
Record heart activity
Cardiac cycle
-complete in 0.8 seconds
-regulated by electrical impulse transmitted through heart wall tissues
-4 heart chambers
—contract: depolarization
—relax: repolarization
- atria contract first, follow by contraction of ventricle
-contraction of ventricle moves blood out of heart to body
-normal rate of rhythm is 60-100 beats per minute
Diastole
Rapid filling phase
Diastole 1st phase
- atria receive blood from superior and inferior vena cava/coronary sinus
- ventricle expelled all blood into aorta
- pressure cause atrioventricular valves to open (tricuspid/mitral valve)
Diastole 2nd phase
Pressure in atria, ventricle begin to equalize
Diastole 3rd phase
- atria contracts to push out last remainder of blood
- final phase of diastole seen as P wave on EKG
Systole
QRS waves
Systole 1st phase
Ventricle are full, begin to squeeze down on themselves to build pressure inside to force semilunar valves to open
Systole 2nd phase
Semilunar valves open
Systole 3rd phase
Ventricular contraction continues until last of blood exits
Systole 4th phase
Ventricles relax
Sinoatrial node
- pacemaker
- generate electrical impulse that activates cardiac cycle
- responsible for atrial contraction
- triggers AV node action
- controls rate of heart contraction
AV node
- gatekeeper
- briefly delays impulses from SA node
- this delay keeps ventricles from contracting too soon
- delay allows atria to contract completely, get all blood out and flowing into ventricles
- passes the impulse at 46-60 beats per minute
Bundle of His
- is triggered into action by AV node
- carry impulse to left/right bundle branches, eventually to purkinje fibers
- bundle branches and prukinje fibers responsible for ventricle contractions
- rate of ventricle cell contraction 20-40 beats per minute
Final phase
Heart relaxes (repolarization)
Holter monitor
- Used for patient experiencing intermittent chest pain or discomfort, who had normal results on resting ECG
- uses 5 leads, record cardiac activity for 24 hours
12 lead ECG
-use 3 bipolar leads, 3 unipolar leads, 6 chest leads (precordial) to record heart activity
Bipolar leads (12 lead ECG)
Limb leads
- 1st leads read on ECG
- lead I: measure current traveling between left arm, right arm
- lead II: measure current traveling between left leg, right arm
- lead III: measure current traveling between left leg, left arm
Unipolar limb leads
AV: augmented voltage
- aVR: right side-trace current traveling toward right arm from midway - left leg, left arm. RA- (LL + LA)
- aVL: left side-trace current traveling toward left arm from midway -right arm, left leg. LA-(RA+LL)
- aVF: foot-trace current travel toward left leg midway - right arm, left arm. LL-(RA+LA)
V1 lead placement
4th inter coastal space, right of sternum
V2 lead placement
4th intercostal space, left off sternum
V4 lead placement
5th intercostal space, midclavicular
V3 lead placement
5th intercostal space, midpoint between V2 and V4
V6 lead placement
5th intercostal space, left mad axillary line
V5 lead placement
5th intercostal space, midpoint between V4, V6
Common source of ECG errors
- poor skin preparation
- loose connection
- touching an electrode, any metal during recording
Electrodes
- Chest leads: 6, placed on upper torso, one electrode placed on each limb
- Right leg: Used as ground electrode to minimize any possible electric shock to patient, to stabilize ECG
- placed on fleshy part of upper arm, lower leg to decrease possibility of muscle voltage (artifacts)
Somatic tremor
Artifact
-body muscle movement
Electrical interference
Artifact
-machine not well grounded, close to other electrical device
Baseline interruption
Artifact
-broken or dislodge lead
Wandering baseline
artifact
Poor skin connection, loose electrode
P waves
- represent depolarization of atria
- measure atrial activity
- seen as small, rounded, upright
PR segment
- part of atrial contraction
- between P wave, QRS wave complex
- no electrical activity
PR intervals
- time takes electrical impulse to be conducted through atria, AV node to beginning of ventricular contraction
- from beginning of P wave to begin of QRS complex
- measure heart efficiency at transmitting impulse down pathway
QRS complex
- represent depolarization of ventricle
- atrial repolarization, usually not seen, occur same time as QRS complex
ST segment
- part of ventricular contraction
- between QRS complex and T waves
- no electrical activity
T waves
- represent heart repolarization (relaxing)
- round, usually higher/broader than P waves
U waves
- Late repolarization
- Not normally seen
- Should be shallow, rounded, upright
ECG paper
- standard mark is 10 mm high
- if baseline off centered, stylus position needs to be adjusted
- lines on paper grid 1 mm apart
- each small box: represent 0.04 seconds
- each large box: represent 0.20 seconds
- cardiac cycle represent by 4 large box
- RL is not displayed, it is ground electrode
Pulmonary function test
Measure:
-air taken into lungs
-air expelled from lungs
-how fast air pushed out of lungs
Includes:
-spirometers, pulse oximetry, diffusion capacity, lung volume, arterial blood gases, cardiopulmonary exercise test
-assist: monitor effectiveness of treatment, classify/detect pulmonary problems-chronic obstructive pulmonary disease, asthma, various allergies, chronic bronchitis, cystic fibrosis
Forced spirometry
- Simple, noninvasive screening test use spirometer measure breathing capacity
- most frequently performed PFT
Forced vital capacity
Measure lung capacity
- inhales deeply as possible, expels rapid/forced expiration. Greatest possible volume of air
- must continue to expel air for total of 6 seconds
- must be repeated 3 times for accuracy
- age, sex, age, weight, height are calculated factors affecting normal results
- result below 80% is abnormal
Contradiction for pulmonary function test
Recent myocardial infarction
- angina
- other serious medical condition
- smoking/eating meal within 6 hours of test
- viral infection
- illness past 2 weeks
- use of some medication may affect test results
Radiology
- Use of radiographic imaging to visualize, diagnose disease within body
- use of radioactive substance to treat disease
- X-ray tube generates beam of xray, aimed at patient
- pass through patient, strike undeveloped film, developed an image appears on film
Computed tomography
- procedure cross-sectional image of body area,
- series of xray transferred to computer, puts together cross-sectional view
- provides rapid, thin, detailed tissue planes
Intravenous pyelogram (IVP)
- visualize urinary structure, colon
- use iodine injection as contrast medium
- pt prepare: clear liquid day before, nothing by mouth 8 hours before
KUB
Flat plate
- frontal supine xray of kidney, ureters, bladder
- use to diagnose abdominal complaints
Cholecystography
- visualize gallbladder
- use contrast medium
- pt prepare: no food/drink 12-14 hours before
Barium enema
Lower GI series
- visualize lower portion of gastrointestinal system
- use barium as contrast medium
- prepare: clear liquids day before
Barium swallow
Upper GI series
- use barium as contrast medium
- prepare: NPO 8 hours before
Angiogram
- visualize heart/ circulation
- use iodine dye, inject into vessel using catheter
- prepare: NPO 4-5 hours before
Arteriogram
- visualize interior of artery
- use iodine dye, injected into artery with catheter
- NPO 4-5 hours before
Positron emission tomography
Produce color image to assess metabolic/chemical activity
-use radioisotope injection
Radiation therapy
Treat disease, shrink cancer tumors
Magnetic resonance imaging
- produce view of internal structure without use of radiation for soft and hard tissues
- no patient preparedness needed
- no metal objects worn, or imbedded
Ultrasound
-High-frequency sound waves produce imagines of deep body structures
-to prepare: depends on type of study
—no eating for several hours before test: pancreas, liver, gallbladder, spleen exam
—drink specific amount of water, not voiding for obstetrical exam
—no eating for several hours before, additionally taking prescribed laxative, water with no voiding within hour before for abdominal exam
-scan of heart: echocardiogram
-image produced by computer: sonogram, hard copy may be produced
Anteroposterior
AP
Pt standing up or supine, beam guided from front to back
Posteroanterior
PA
Pt standing up or supine, bean guided back to front
Right lateral
RL
-pt lying on right side, beam guided right side to left side
Left lateral
LL
-pt lying on left side, beam guided from right side to left side
Oblique
Pt lying at angle
-beam guided through body: left posterior /left anterior oblique; right posterior/right anterior oblique
Monitored dosimeter
Radiation exposure badge worn by staff present during xray, monitors cumulative exposure to radiation
- worn outside of clothing, around chest/torso
- monitors dose received to unprotected parts
Lead shield
Shield used to cover organs that do not need to be x-rayed
Pregnancy
As precautionary measure, female pt must be asked if they could possibly be pregnant
-if so, radiologists must be notified before proceeding
Xray equipment
Maintenance of equipment should be scheduled regularly to ensure it is proper working order
Lead aprons/gloves
Used by all participating staff members, not behind protective barrier
-all participant staff should preferably be standing behind barrier lined with lead when xray being obtained
Proper disposal
All staff must follow occupational safety and health administration approved steps use to properly dispose of photo and xray processing waste
-hazardous waste, extremely hazardous waste
Creatinine
- normal: 0.4 to 1.5 mg/dL
- above normal: impaired renal function, chronic nephritis, urinary tract obstruction
- below normal: muscular dystrophy
Blood urea nitrogen
- normal 8-25 mg/dL
- above normal: Kidney disease, urinary tract obstruction,
- borderline high: congestive heart failure, internal bleeding
- below normal: liver failure, negative nitrogen balance, impaired absorption, over hydration, low protein diet
Uric acid
- normal: male-3.5-7.2 mg/dL, female-2.6-6 mg/dL
- above normal: gout, chronic kidney failure, kidney stones, radiation poisoning, toxemia of pregnancy, starvation, diet rich in purines
- below: not significant
Total protein
- normal: 6-8 g/dL
- above normal: dehydration, lupus erythematosus, rheumatoid arthritis, chronic infection, acute liver disease
- below: severe liver disease, malabsorption, nephrotic syndrome, diarrhea, exfoliating dermatitis, severe burns
Total bilirubin
- normal: 0.3-1.2 mg/dL
- above: liver disease, bile duct obstruction, hypothyroidism, jaundice
- below: drug addiction (barbiturates)
Alkaline phosphatase
Normal: 30-115 mU/mL
- above: gallstone, liver lesion, hepatitis, cirrhosis of liver, Paget’s disease, metastatic bone disease, osteitis deformans
- below: osteomalacia, malnutrition, hypothyroidism, pernicious anemia, scurvy, placental insufficiency
Serum aspartame aminotransferase
- normal: adult-5-40, children-10-50, infants-20-60 u/l
- above: myocardial infarction, severe arrhythmias, angina, cirrhosis liver, acute hepatitis, infectious mononucleosis, hepatic necrosis, acute pancreatitis, acute hemolytic anemia, acute renal disease, severe burns, muscular dystrophy
- below: beriberi, uncontrolled diabetes mellitus with acidosis
Serum alanine aminotransferase
- normal: adults-7-56, children 10-35
- above: hepatocellular disease, obstructive jaundice, active cirrhosis, metastatic liver tumor, mild pancreatitis, liver congestion, hepatic injury in myocardial infarction
- below: not significant
