Blood sample collection in children

Do’s and Don'ts

Dr Swati Bhave

Preparation of Pediatric Patients

• Find out –Is it the first time for the child?

Find out about past experience. How did the child react ? How did the parents react ?

• Explain – To parent and child about

procedure (if possible with dolls or puppets)

Explain need of second attempt if required

Parental co-operation

•Assess - Parental ability to participate or assist you

•Decide - Whether parent should be present or not

• If present - Decide how will they assist : physical restrain, distraction, emotional support , explanation

How to relieve Anxiety & Fear

• Collect blood away from other patients in a special room. Never in the hospital bed. This is a comfort zone

• Area should be child friendly. Uniforms should be colourful

• Keep equipment out of site • Ask child’s preference of hand • Allow child to select comfort object• Stop procedure if child combative • Try later or another person

Minimizing PAIN

• Topical anesthetic like AMETOP, EMLA • Cost, time ( 10-60min)• More than one site tried, allergy • Sucrose or pacifier

Selection of Site

• Very important to get adequate volume • Will be decided by

– Age of the child: heel or finger stick, IV – Whether arterial or venous blood required – Equipment available eg neonate capillary

tubes, vacutainers, routine needle & syringe etc

Infants and Neonates HEEL stick puncture

• Lateral plantar bottom surface • 3 - 5 min Pre-Warming > blood flow (arterializes)• Pediatric lancet New born 2.5mm L /1mm D,

Preterm o.75 mm L / 0 .85 mm D• Depth of major BV is 0.03 mm to 1.6 mm from

skin to calcaneous• > 2.4 mm depth injury: Osteomyelitis

Infants and Neonates HEEL stick puncture

• Do not use anteromedial area or posterior curve of C

• Do not use alcohol swabs to stop bleeding : stinging; Use sterile gauze for pressure

• Do not use adhesive tapes :maceration and bruising of skin

• Do not squeeze or milk excessively : hemolysis or dilutes blood with tissue and interstitial fluid : erroneous results

• Discard first drop • Complications cellulitis, abscess, scarring, tissue

loss, calcified nodules

Older child : > one yr age finger prick

• Damaged veins, arm in cast or bandaged • Do not use if edema, infection, <

circulation• Skin to BV depth 1.5 -2.4 mm• Should not go >2.4 mm deep• Pediatric lancet sizes 1.75/1.25/0.85 mm

Intravenous blood collection

• Site selection • Tourniquet not excessively tight

• Special precautions when– Heparin lock or – IV line collection

What is required from the sample

• Does the test require : whole blood , serum or plasma.

• How much is the volume required : 2, 4, 5, ml etc. Pre-term 10 ml may be 5 % of total volume

• What are the special bulbs or ready made tubes required : e.g. fluoride bulb for sugar, chemistry bulb for urea , EDTA for hematology etc

In What to collect blood ?

BULB FUNCTION USED FOR

EDTA Chelates Ca preserves cellular elements

CBC,Reticulocytes, ESR,G6PD, Hb electrophoresis

Trisodium citrate

Converts Ca into non-ionized form

PT, APTT, TT Fibrinogen etc

Flouride

Enzyme poison. Inhibits Glycolysis In RBC (Glucose destroyed at 5% / hr)

Glucose

ORDER of drawing

• This is important - so that additives in one tube will not contaminate specimen in subsequent tubes

• Blood culture • Non Additive tube • Coagulation tube • Non Additive tube

• If using syringes minimize clotting by filling additive tubes before non additive

When & How to get Serum & Plasma

• Serum sample – blood collected

without any anti-coagulant and centrifuged

– clear supernatant fluid devoid of any fibrin products

• Plain bulb– Most enzymes,– Biochemical LFT,KFT, – S Electro.– Serological :Widal,

VDRL

• Plasma sample – blood collected & mixed

with anticoagulant and centrifuged

– clear supernatant fluid with thrombosis inhibited. Most satisfactory sample. No changes occur in blood

• Heparinized bulb– PH, NH4, RBC levels,

Plasma cortisol, testosterone, globin,cholinesterase

For Special Testing

• PCR, Genetic, ammonia, blood gases, drug, antibiotic & hormone levels etc.

• Before collection of sample ascertain that you know everything about the sample collection

• Confirm from lab how much volume, what bulb, procedure, timing etc

• Recollection of blood is distressing for everyone: Child-parent- doctor & adds to cost

HEMOLYSIS OF SAMPLES

• Contact with water • Excessive heat or cold • Rigorous mechanical injury to RBS

( thin gauge ) • Prolonged storage • Hemolyzed samples will give

erroneous results

PREVENTION OF HEMOLYSIS

• Equipment used to collect : absolutely dry

• Minimum constriction of limb• Use correct gauge • Collect slowly and steadily • Remove needle and put

immediately into the bulb• Easier if collection in Vacutainer

Important steps before collection

• Identification of the patient • Labeling correctly: very very important • Re-checking which test is required• Keeping ready all the necessary equipment :

drawing of blood and bulbs for collection• Clean up the area before and after

collection

Following safety precautions

• Do no harm to your patient – Ensure use of safe and sterile equipment

• Do no harm to yourself – Follow universal precautions – Avoid needle stick injuries and splashing of

blood into your eyes, skin or mucous membrane

• Do no harm to the community – Ensure that you have safely and correctly

disposed all equipment so that no other person can get exposure

Transport & Storage of samples

• Ideally the sample should be collected in the laboratory and immediately into the processing

• If it cannot be sent immediately one should follow instructions carefully for

Storage • where should it be kept ? : room temp,

cold storage-what temp Transport • What are the precautions during

transport

Summary

• Blood collection in children is a traumatic and invasive procedure

• All efforts should be made to reduce the discomfort

• Care should be taken to avoid need for repeat puncture