types of punctures

TYPES OF

PUNCTURESBy Dr Fatehia Awny

Faculty of Health Sciences .

BAU 2015

Skin puncture Earlobe puncture.

Types of punctures:

Finger puncture heel stick

1. for patients in whom venous access is difficult,

2. when small quantities of blood are sufficient for

testing.

In newborns, heel sticks are the preferred

collection method for small volumes of

blood.

Why Perform a Skin Puncture?

CAPILLARY COLLECTIONS MAY BE

PREFERABLE OVER VENIPUNCTURE:

Severely burned patients

Obese patients

Patients with thrombotic tendencies

Elderly patients or others in whom superficial veins

are very fragile or inaccessible

Patients performing self-testing

Point-of-care testing

Newborn testing

Patients who have a paralyzing fear of needles

Differences Between Skin Puncture Blood and

Venipuncture Blood!!!!!!!!!!!!!!!!!!!!!!!

FINGER PUNCTURE:

Preparation for finger stick

1. Place all collection materials

on top of disposable pad.

Open the lancet, alcohol

swabs, gauze, bandage, and

other items. Have all items

ready for blood collection.

FINGER PUNCTURE:

CHOOSE THE FINGER CAREFULLY

Best locations for a finger stick is the 3rd and 4th fingers of the non-dominant hand.

Avoid the 2nd and 5th fingers if possible.

Perform the stick off to side of the center of the finger.

NEVER use the tip or center of the finger.

FINGER PUNCTURE:

Massage or Warm the site• Avoid fingers that are cold,

cyanotic, swollen, scarred

or covered with a rash.

• Massage to warm the

finger and increase blood

flow by gently squeezing

from hand to fingertip 5-6

times.

FINGER PUNCTURE:

Clean and DRY the site

Cleanse fingertip

with 70% isopropyl

alcohol

Wipe dry with clean

gauze or allow to air

dry.

Caution: Alcohol can

falsely elevate or lower

blood glucose results.

FINGER PUNCTURE:Hold the finger in an upward

position and lance the

finger (across the

fingerprint) between the

side and the pad with the

proper size lancet

(adult/child). Press firmly

on the finger when making

the puncture. Doing so

will help you to obtain the

amount of blood you need.

FINGER PUNCTURE:

Finger Stick location

• Using a sterile lancet, make a skin puncture just off the center of the finger pad.

• Wipe away the first drop of blood (which tends to contain excess tissue fluid).

5. Apply slight pressure

to start blood flow.

Blot the first drop of

blood on a gauze pad

and discard in

appropriate biohazard

container.

FINGER PUNCTURE:

Keep the finger in a downward

position and gently massage it

(but do not “milk”) to maintain

blood flow.

FINGER PUNCTURE:

SUMMARY

If child is <12 months of age, the lancet

must have a depth of 2 mm or less, and a

fingerstick MAY NOT be performed – must

do a heel stick instead

The heel is used for dermal punctures on infants

less than 1 year of age because it

contains more tissue than the finger, and has not

yet become callused from walking.

No nerves ,bones or tendons near by

WHY HEEL STICK?

Hatched areas (arrows)

indicate safe areas for

puncture site.

heel stick:

Warm site with soft cloth moistened with warm water (up to 41

oC) for 3 – 5

minutes.

HEEL STICK:

Cleanse site with

alcohol prep.

Wipe DRY with sterile

gauze pad.

HEEL STICK:

Puncture heel.

Wipe away first

blood drop with

sterile gauze pad.

Allow another

LARGE blood drop

to form.

HEEL STICK:

Mainly used for bleeding time .

Principle

The bleeding time is the time it takes for a small

standardized wound, introduced into the capillary bed

of the finger or earlobe,to stop bleeding. It is

dependent upon:

1- the elasticity of the skin and capillary vessels,

2-the efficiency of the tissue fluids

3-the mechanical and chemical action of the

thrombocytes (blood platelets).

EARLOBE PUNCTURE:

Make a small wound 3 mm deep in the lateral aspect of a fingertip or the lower portion of the ear lobe, using a suitable lancet. The wound should be sufficiently deep to give a free flow of blood without squeezing.

Start the stop watch immediately after the puncture is made. Though the stop watch is started a few seconds after puncturing the skin, very little error results in the bleeding time.3.

At intervals of one-half minute gently blot the blood from the wound with a piece of filter paper, being careful not to touch the skin.4.

EARLOBE PUNCTURE:

The interval of time between the puncture and the

cessation of bleeding is the bleeding time. The

blood should fail to appear on the filter paper in 1-3

minutes. All abnormal findings should be

rechecked.

NORMAL : 1-3 minutes

EARLOBE PUNCTURE:

Specimen Types

Blood

–Proper collection vial

–Collection comprised of two bottles:

Aerobic

Anaerobic

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Blood culture bottles.

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SPECIMEN TYPES

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PHLEBOTOMY

Phlebotomy procedure

Important to all laboratory testing

Sample’s quality determines accuracy of its final result

Anticoagulant

Mixed with blood to prevent coagulation

Three anticoagulants are used in the hematology

laboratory

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PHLEBOTOMY

Anticoagulant EDTA – prevents coagulation by chelating Ca2+

Use for tests: CBC, Hct, Plt, Retic, peripheral blood smearexamination, flow cytometry

Sodium citrate – prevents coagulation by binding Ca2+

Used for coagulation studies

Lithium heparin – prevents coagulation by interactingwith antithrombin Used for osmotic fragility: not appropriate for routine

hematology testing

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EQUIPMENT

Sample collection tubes Evacuated sample collection tubes

Sterile

Color coded to indicate type of anticoagulant present or the

lack of anticoagulant

Only small amounts of sample for analysis necessary

Interior of a sample collection tube is a vacuum

Capillary punctures Microcollection tubes

Do not contain a vacuum

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CAPILLARY PUNCTURE

Collection tubes

Should be properly labeled with patient’s name, unique

ID number, date, and time of collection

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SPECIMEN COLLECTION

Anticoagulant of choice

Sodium citrate, 3.2%

Ratio of anticoagulant : whole blood is 1:9

> 55% hematocrit

Smaller volume of plasma relative to citrate

Excess free citrate binds calcium in the test procedure

Falsely prolonged clotting times

Adjust citrate concentration

Citrate tubes are available that draw 4.5 mL, 2.7 mL, 1.8 mL

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SPECIMEN COLLECTION

Anticoagulant to blood ratio

1:9 ratio critical for valid results

If under-filled – ↑ citrate, bind calcium in test procedure

Falsely prolonged test results

If overfilled – insufficient calcium bound

Clotting can occur in tube

Falsely prolonged results

Accurate labeling of tube

Include pre-or postinfusion, time of draw

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SPECIMEN COLLECTION

Specimen draw time

Check patient history of receiving blood products

If testing done within the half-life of administered clotting factor

then test may measure transfused component as well as the

patient's component

Fibrinolytic factors – diurnal variability

Platelet studies – medication history

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SPECIMEN PROCESSING

Plasma for coagulation testing

Citrated whole blood is centrifuged

Platelet-poor plasma (PPP)

Platelet-rich plasma (PRP)

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SPECIMEN PROCESSING

Platelet-poor plasma

Citrated specimen centrifuged for 15 minutes at 2500xg

< 10 x 109/L platelets

Depending on coagulation instrumentation

Leave plasma on top of packed cells or

Remove plasma with plastic pipette – plastic tube with cap

Leave small amount of plasma on top

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SPECIMEN PROCESSING

Use platelet-poor plasma because Platelets contain PF4

Neutralizes heparin

Platelets contain phospholipids Affect LA testing and factor assay testing

Platelets contain proteases Alter results for von Willebrand testing

Any clot in specimen Specimen unacceptable

After removing PPP, twirl applicator stick in packed cells to

detect clots

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SPECIMEN PROCESSING

Platelet-poor plasma

Separated plasma

Stored at 18-24°C or 2-8°C for up to 4 hours

If testing is delayed > 4 hours

Stored at -20°C for up to 1 week

Stored at -70°C for up to 6 months

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SPECIMEN PROCESSING

Platelet-poor plasma

Frozen specimens

Thawed rapidly at 37°C

Excessive heating can destroy Factor V and VIII

Never store in self-defrost freezers

Special testing may require special collection and

storage procedures

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