hema - veni and anticoagulant Flashcards
first step in skin preparation
cleanse the skin with alcohol swab
what should be maintained in skin preparation?
asepsis
2 sources of microbial contamination
- hand of the phlebotomists
- skin of the patient
what are the blood collection method in skin puncture
capillary blood/peripheral blood
site of the capillary blood
finger, earlobe and medial/lateral portion of the plantar surface of the foot
skin puncture order of draw
lavender-plasma additive-serum tubes
puncture site for infants under 12 mos
lateral/medial plantar heel surface
puncture site for infants below 12 mos, children and adult
palmar surface of last digit of 2nd, 3rd, 4th finger
two methods of venipuncture
syringe and evacuated tube method
needle length range
1 inch for routine venipuncture and 1.5 inches for patients with deep veins
angle of the syringe
15 degrees
suitable needle gauge for adults
19-21 g
suitable needle gauge for childreen
23g
needle used when blood is to be collected from a very small vein
butterfly needles (21, 23, 25 g)
site for venipuncture?
antecubital fossa
veins in the antecubital fossa
median cubital, median cephalic, and basilic
alternate sites
ventral forearm, wrist area, back of the hand and ankle/foot
order of draw
yellow - blue - red - green - lavender - gray
specimen rejections
clotted specimen, severely hemolyzed specimen, improperly labeled specimen, specimen too old, failure to meet volume criteria, improperly dilluted capillary specimen, leaking tube, delay in transport and collection of specimens in wrong tube.
immediate local complications
haemoconcentration, collapse of the vein, failure of blood to enter the syringe.
immediate general complications
syncope
late local complications
thrombosis of the vein, thrombophlebitis, hematoma
errors in s.c
misidentification of patient, mislabeling of specimen, short draws, mixing problem, wrong anticoagulant, hemolysis/lipemia, hemoconcentration of prolonged torniquet, extreme temperature, delayed delivery, processing errors
peaks at 4-6 am, lowet at 8 pm to 12 am
cortisol
lower at night, increased with stress
adrenocorticotropic hormone
lower at night, increased with supine>standing
plasma renin activity
lower at night
insulin, aldosterone
higher in the afternoon and evening
growth hormone, acid phosphate
increase with exercise
thyroxine
higher with stress and 4-8 am and 8-10 pm
prolactin
peaks early in the morning, decreases up to 30%
iron
4% decrease supine
calcium
commonly used anticoagulants
edta, double oxxalate, sodium citrate, sodium flouride, heparin, acd, cpd and cpda.
chelates ca (calcium)
EDTA
uses of edta
cell count, blood smear, platelet count and for routine hematology
EDTA salts
sodium, potassium and lithium
____ more soluble than _____
dipotassium, disodium
equally effective, sample of blood can be used for chemical investigations
dilithium
liquid form edta salt
tripottassium
disadvantage of tripotassium edta salt
dilution, shrinkage of rbc, decrease in 2-3% PCV in 4 hours and gradual increase in MCV
EDTA salt that is not recommended because of high pH
trisodium edta
coding of vial of EDTA
lavender cap
recommended EDTA concentration
1.5-2.0 mg/ml
binds ca in soluble complex
Na citrate
used for coagulation studies
na citrate
vial coding of na citrate
blue
acts as chelating calcium in blood used as 3.2% and 3.8%
trisodium citrate
gets rid of the calcium but not strongly as edta
na citrate
binds ca to form insoluble Ca oxalate
oxalate
disdvantages of oxalate
- Calcium in the blood combines with oxalate to form insoluble calcium oxalate which precipitates.
- They are phagocyted by neutrophils-distort WBC morphology-good for smears
- Never used In blood to be transfused- as it is toxic and calcium oxalate precipitate may harm.
prevents glycolysis
flouride
double action of sodium flouride
- prevents clotting by chelating calcium
- prevents all phosphatase action
- prevents glycolysis for 3 days
flouride is used for ___
determination of sugar
in bacterial septicemia, fluoride inhibition of glycolysis is neither
adequate nor effective
common disadvantages with calcium chelators
- Amylase activity inhibited by oxalate and citrate
- LDH and Acid Phosphatase inhibited by oxalate.
- Fluoride, heparin OR EDTA interfere with accurate determination of electrolytes.
concentration of lithium or sodium salt
10-20 ml
recommended add in heparin
lithium
heparin is produced by
basophils and mast cells
heparin accelerates
antithrombin III
heparin neutralizes ____ and prevents formation of ____
thrombin ; fibrin
heparin prevents formation of
clots and extension of existing clots
heparin don’t ___
break down clots already formed
blood storage for heparin
5-10 ml
sample collection for heparin
0.5-2.0ml
uses of heparin
ammonia, carboxyhemoglobin, blood gases, electrolytes, esr, methamoglobin, osmotic fragility and hla typing
disadvantages of heparin
costly, Not suitable for blood counts as it often induces platelet and leucocyte clumping, Should not be used in study of PCR with restriction enzymes because it inhibits enzyme activity.
used for routine hematology
edta (lavender)
used for coagulation studies
sodium citrate (blue)
fused for glucose determination
k-oxalate/sodium fluoride (grey)
used for collection of serum
no additive, red
used for preservation of RBC for blood banking and HLA typing
ACD (yellow)
used for inhibition of thrombin activation
Heparin (green)
required volume for preservation of blood
15mL of ACD and 14mL of CPD and CPDA-1 is required for preservation of blood
initial pH of acd, cpd and cpda
Initial pH of ACD 5.0 and of CPD & CPDA-1 is 5.6
storage time at 2-6 degree celcius for ACD, CPD AND CPDA-1
storage time at 2-6 degree celsius for ACD and CPD is 21 days and for CPDA-1 is 35 days.
causes chelation of calcium
citrate
prevents fall in pH
sodium diphosphate
addition of glucose prolongs survival of stored RBC as it is required for metabolism. Glucose passes from plasma to RBC and is utilized for energy production.
dextrose
2 pathways for energy production
90% embedem mayeroff and 10% pentose phosphate
there is breakdown of glucose into lactate though anaerobic glycolysis.
90% embedem mayeroff pathway
added in modified CPD as it improves viability of RBC because of enhanced ATP production.
adenine
pathway through aerobic glycolysis
10% pentode phosphate
fairly weak tribasic hydroxy acid.
citric acid
storage environment of RBC is altered by adding certain nutrients after removal of plasma.
additive system
adjust osmotic pressure
sodium chloride
maintains high level of ATP in RBC
adenine
prevents disintegration of RBC
mannitol