Maximum Age for Drawing Blood From a Scalp Vein

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WHO Guidelines on Drawing Blood: Best Practices in Phlebotomy. Geneva: World Health Organization; 2010.

WHO Guidelines on Drawing Blood: Best Practices in Phlebotomy.

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6 Paediatric and neonatal blood sampling

The information given here supplements that given in Chapters 2 and 3. Users of these guidelines should read Chapters 2 and 3 before reading the information given below. This chapter covers background information (Section 6.1), practical guidance (Section 6.2) and illustrations (Section 6.3) relevant to paediatric and neonatal blood sampling.

6.1. Background information on paediatric and neonatal blood sampling

This chapter discusses aspects specific to paediatric and neonatal blood sampling (60, 61). Anyone taking blood from children and neonates must be well trained and practiced in venepuncture techniques. A uniform sampling technique is important to reduce pain and psychological trauma.

6.1.1. Choice of procedure and site

The choice of site and procedure (venous site, finger-prick or heel-prick – also referred to as "capillary sampling" or "skin puncture") will depend on the volume of blood needed for the procedure and the type of laboratory test to be done. Venepuncture is the method of choice for blood sampling in term neonates (62, 63); however, it requires an experienced and trained phlebotomist. If a trained phlebotomist is not available, the physician may need to draw the specimen. Section 7.1 provides information on when a capillary blood specimen from a finger-prick or a heel-prick is appropriate. The blood from a capillary specimen is similar to an arterial specimen in oxygen content, and is suitable for only a limited number of tests because of its higher likelihood of contamination with skin flora and smaller total volume.

Finger and heel-prick

Whether to select a finger-prick or a heel-prick will depend on the age and weight of the child. Section 7.1 explains which procedure to select, based on these two elements.

Patient immobilization is crucial to the safety of the paediatric and neonatal patient undergoing phlebotomy, and to the success of the procedure. A helper is essential for properly immobilizing the patient for venepuncture or finger-prick, as described in Section 6.2.

6.2. Practical guidance on paediatric and neonatal blood sampling

6.2.1. Patient identification

For paediatric and neonatal patients, use the methods described below to ensure that patients are correctly identified before taking blood.

• Use a wrist or foot band only if it is attached to the patient; DO NOT use the bed number or a wrist band that is attached to the bed or cot.

• If a parent or legal guardian is present, ask that person for the child's first and last names.

• Check that the name, date of birth and hospital or file number are written on the laboratory form, and match them to the identity of the patient.

6.2.2. Venepuncture

Venepuncture is the preferred method of blood sampling for term neonates, and causes less pain than heel-pricks (64).

Equipment and supplies for paediatric patients.

• Use a winged steel needle, preferably 23 or 23 gauge, with an extension tube (a butterfly):

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  avoid gauges of 25 or more because these may be associated with an increased risk of haemolysis;

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  use a butterfly with either a syringe or an evacuated tube with an adaptor; a butterfly can provide easier access and movement, but movement of the attached syringe may make it difficult to draw blood.

• Use a syringe with a barrel volume of 1–5 ml, depending on collection needs; the vacuum produced by drawing using a larger syringe will often collapse the vein.

• When using an evacuated tube, choose one that collects a small volume (1 ml or 5 ml) and has a low vacuum; this helps to avoid collapse of the vein and may decrease haemolysis.

• Where possible, use safety equipment with needle covers or features that minimize blood exposure. Auto-disable (AD) syringes are designed for injection, and are not appropriate for phlebotomy.

Preparation

Ask whether the parent would like to help by holding the child. If the parent wishes to help, provide full instructions on how and where to hold the child; if the parent prefers not to help, ask for assistance from another phlebotomist.

Immobilize the child as described below.

• Designate one phlebotomist as the technician, and another phlebotomist or a parent to immobilize the child.

• Ask the two adults to stand on opposite sides of an examination table.

• Ask the immobilizer to:

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  stretch an arm across the table and place the child on its back, with its head on top of the outstretched arm;

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  pull the child close, as if the person were cradling the child;

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  grasp the child's elbow in the outstretched hand;

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  use their other arm to reach across the child and grasp its wrist in a palm-up position (reaching across the child anchors the child's shoulder, and thus prevents twisting or rocking movements; also, a firm grasp on the wrist effectively provides the phlebotomist with a "tourniquet").

If necessary, take the following steps to improve the ease of venepuncture.

• Ask the parent to rhythmically tighten and release the child's wrist, to ensure that there is an adequate flow of blood.

• Keep the child warm, which may increase the rate of blood flow by as much as sevenfold (65), by removing as few of the child's clothes as possible and, in the case of an infant, by:

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  swaddling in a blanket; and

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  having the parent or caregiver hold the infant, leaving only the extremity of the site of venepuncture exposed.

• Warm the area of puncture with warm cloths to help dilate the blood vessels.

• Use a transilluminator or pocket pen light to display the dorsal hand veins and the veins of the antecubital fossa.

Drawing blood

• –

  hand hygiene;

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  advance preparation;

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  patient identification and positioning;

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  skin antisepsis (but DO NOT use chlorhexidine on children under 2 months of age).

• Once the infant or child is immobilized, puncture the skin 3–5 mm distal to (i.e. away from) the vein (66); this allows good access without pushing the vein away.

• If the needle enters alongside the vein rather than into it, withdraw the needle slightly without removing it completely, and angle it into the vessel.

• Draw blood slowly and steadily.

6.2.3. Finger and heel-prick

See Section 7.2, which describes the steps for both finger and heel-pricks, for paediatric and neonatal patients, and for adults.

Select the proper lancet length for the area of puncture, as described in Section 7.2.

6.3. Illustrations for paediatric and neonatal blood sampling

Copyright © 2010, World Health Organization.

All rights reserved. Publications of the World Health Organization can be obtained from WHO Press, World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland (tel.: +41 22 791 3264; fax: +41 22 791 4857; e-mail: tni.ohw@sredrokoob). Requests for permission to reproduce or translate WHO publications – whether for sale or for noncommercial distribution – should be addressed to WHO Press, at the above address (fax: +41 22 791 4806; e-mail: tni.ohw@snoissimrep).

Bookshelf ID: NBK138647

Maximum Age for Drawing Blood From a Scalp Vein

Source: https://www.ncbi.nlm.nih.gov/books/NBK138647/

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