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Capillary Blood Sampling Procedure in Pediatric Population American Journal of Biomedical Science & Research


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Capillary blood sampling is an essential method of blood collection performed by nurses of all skill levels to obtain samples for routine laboratory tests in neonates. Newborn screening tests require small, but adequate amounts of blood. Accuracy of their results depends, however, on proper sample collection technique. Heel sticks are the most commonly performed invasive procedures in neonatal intensive care units. Clinical guidelines recommend drawing blood from an infant’s heel from a very precise site to avoid trauma, pain and tissue damage in infants.
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Capillary Blood Sampling Procedure in Pediatric
Copy Right@ Malinowski M
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American Journal of
Biomedical Science & Research
ISSN: 2642-1747
Mini Review
Capillary blood collection has been known around for decades.
When it began, the procedure was used to obtain blood from infants
for genetic screening tests. Newborn screening is nowadays the
routine practice of testing every newborn for certain harmful or
potentially fatal disorders that are not otherwise apparent at birth.
Some examples are: phenolketonuria, congenital hypothyroidism,
      
      
acidaemia, glutaric aciduria type 1 and homocystinuria (pyridoxine
unresponsive) [1,2].
Early detection allows treatment that may prevent development
of serious health problems. Newborn screening tests help to identify
potentially treatable or manageable congenital disorders within
and serious lifelong disabilities can be avoided or minimized
         
critically ill neonates also frequently require repeated analysis of
blood chemistry, hematology and blood gas values in addition to
mandated metabolic screening.
In pediatrics it is especially important to obtain small but
adequate amounts of blood. Drawing blood by venipuncture from
       
too large quantities of blood may result in anaemia. Additionally
infants have a limited number of sites that can be used for arterial or
venous sampling. That is why blood sampling for infants vary from
         
with a blade safety lancet version. Due to this fact different blood
drawing technique needs to be used and several conditions must
Choice of Site
According WHO guidelines on drawing blood: best practices
in phlebotomy, the heel is usually the preferred site for capillary
testing in pediatric and neonatal patients [3]. It is crucial to choose
an adequate part of the heel. When puncturing an infant’s heel,
the site must be on the plantar surface medial posteriorly from
  
the heel bone (calcaneus) is not located beneath these areas, so
there is no risk of bone violation. Safest sites for heel stick are outer
edges of heel (Figure1). Area between outer edges may be used as
site selection is important for minimizing pain and avoiding contact
Malinowski M*
HTL-Strefa S.A., Regulatory Affairs Department, Poland
*Corresponding author:
To Cite This Article: Malinowski M. Capillary Blood Sampling Procedure in Pediatric Population. 2020 - 9(4). AJBSR.MS.ID.001406. DOI: 
Received: March 13, 2020; Published: July 08, 2020
Capillary blood sampling is an essential method of blood collection performed by nurses of all skill levels to obtain samples for routine laboratory
tests in neonates. Newborn screening tests require small, but adequate amounts of blood. Accuracy of their results depends, however, on proper
sample collection technique. Heel sticks are the most commonly performed invasive procedures in neonatal intensive care units. Clinical guidelines
recommend drawing blood from an infant’s heel from a very precise site to avoid trauma, pain and tissue damage in infants.
Abbreviations: AWHONN: Association for Women’s Health, Obstetric and Neonatal Nurses; NANN: National Association of Neonatal Nurses;
WHO: World Health Organization
American Journal of Biomedical Science & Research
Am J Biomed Sci & Res Copy@ Malinowski M
with the calcaneus. The posterior pole of the heel should not be
used for a heel stick, because this site is where the calcaneus is in
a) The posterior curvature of the heel;
b) The central area of the infant foot (area of the arch).
and cartilage. The arch area offers no advantage over puncturing
the heel and must not be used;
           
distance from skin surface to bone in the thickest portion of the
   
        
contaminate the blood specimen;
 
f) Earlobes [4].
Figure 1: Procedure of capillary blood sampling from the infant’s heel. a) Recommended test sites. Infants have a limited number of sites that can
be used for blood sampling. That is why blood is usually drawn from an infant’s heel; b) Unlock the device by pressing the safety lock; c) Place
the device on the previously cleaned test site and press the trigger to activate the device; d) Collect blood sample and discard the used device in
sharps container.
Incision Length
Apart from choosing an adequate site on the infants heel,
incision depth is equally important, as the heel callus is still
forming and it is crucial not to interfere into bone formation. The
recommended incision length depends on the age of the patients
and its weight (Table 1). Various publications for the newborn
    
a 3 kg baby from outer skin surface to bone for medial and lateral
heel is 3.32 mm. The posterior heel site should be avoided, to reduce
the risk of calcaneal puncture and subsequent osteochondritis. A
lancet slightly shorter than the estimated depth needed should be
used because the pressure compresses the skin; thus, the puncture
depth will be slightly deeper than the lancet length. In general, heel
           
at any other site [6].
Table 1: Recommended depth and applications for use for skin puncture to collect blood from an infant’s foot.
Applications for use Incision depth (mm) Incision width (mm)
  1.4
  
 1
 2 3
Disinfection of the Site
The skin puncture site must be properly cleansed using sterile
cotton or gauze and disinfected with an appropriate disinfected
agent. For adults an alcohol is preferably to clean the site. However,
some discrepancies appear when it come for pediatric population.
Although many antiseptics have been used in neonates for several
decades, there is no clear guidance regarding the best antiseptic
for use in neonatal intensive care unit. Current evidence based on
      
antiseptic agent over another.
       
[3] rather than povidone iodine because blood contaminated
with povidone iodine may falsely increase levels of potassium,
phosphorus or uric acid in laboratory test results. According
to the Association for Women’s Health, Obstetric and Neonatal
Nurses (AWHONN) and the National Association of Neonatal
Am J Biomed Sci & Res
American Journal of Biomedical Science & Research
Copy@ Malinowski M
      
      
should be use as disinfected agents and isopropyl alcohol usage
is discouraged because less effective, drying to skin. Both of them
must be completely removed with sterile water or sterile saline to
an evidence based review was published concluded some evidence
including avoiding of alcohol and povidone iodine. In the extreme
preterm neonates topical antiseptics should be used with special
   
alcohol wipes should not be used for skin preparation in neonates
and premature infants because it can cause burns and blisters.
Tepid plain water is preferable [10].
Type of Devices
Historically, skin puncture has been performed with either
a sterile disposable surgical blade or lancet. The surgical blade
presents hazards to both the infant and the blood drawer. Since
the depth of puncture cannot be precisely controlled, the infant
 
devices have different tip lengths and thus make a shallower or a
deeper puncture. Some of these devices puncture the skin, while
others provide an incision, depending upon the design features.
These products are designed to control the length and depth of the
       
yield single drops for capillary blood in older children and adults.
    
for capillary heel sampling in infants. The devices use a surgical
steel blade that slices, rather than stabs. The depth and length of
incision are then better controlled by this kind of device [8]. The
       
         
  
a plastic holder and, upon release, sweeps down to make a small
incision and then automatically retracts upward back into the
     
incision devices based on less damage to the heel, less collection
time, fewer punctures required, less haemolysis in samples, less
pain, and better wound healing. Devices with an arched shaped
incision provide better quality blood samples, require fewer heel
       
is effective in providing a quality sample, reducing: the number
of heel puncture sites per test, the time taken to complete the
test, the need for squeezing the heel, bruising, the time the baby
cried, and the need to repeat the test [11]. The selection of the
most appropriate heel stick device in this fragile population, who
undergo numerous capillary blood collections procedures, may
related to prolonged distress and repeated pain exposure in the
neonatal period [12].
Heel stick is a minimally invasive and easily accessible way
of obtaining capillary blood samples for various laboratory
     
 
sampling had obvious applications in this area. To get a sample of
capillary blood, some practical skills and knowledge how to avoid
     
The development of newer, more effective, and less painful lancing
devices may increase the relative utility of heel stick.
1.    
2. 
        
3. 
4.            
          
 
of newborn heel skin punctures based on anatomical measurements and
6.        
    
       
clinical practice guideline. Association of Women’s Health, Obstetric
and Neonatal Nurses and the National Association of Neonatal Nurses. J
8.      
    
10.         
11. Vertanen H, Fellman V, Brommels M, Viinikka L. (2001) An automatic
incision device for obtaining blood samples from the heels of preterm
infants causes less damage than a conventional manual lancet. Arch Dis
12. Hammermeister M, Baskin L, Lemaire C, Naugler C. (2013) Comparison
of two infant lancet devices on ease of use and post lance bleeding times.
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Full-text available
Infants in the neonatal intensive care unit are highly susceptible to healthcare associated infections (HAI), with a substantial impact on mortality, morbidity and healthcare costs. Effective skin disinfection with topical antiseptic agents is an important intervention in the prevention or reduction of HAI. A wide array of antiseptic preparations in varying concentrations and combinations has been used in neonatal units worldwide. In this article we have reviewed the current evidence of a preferred antiseptic of choice over other agents for topical skin disinfection in neonates. Chlorhexidine (CHG) appears to be a promising antiseptic agent; however there exists a significant concern regarding the safety of all agents used including CHG especially in preterm and very low birth weight infants. There is substantial evidence to support the use of CHG for umbilical cord cleansing and some evidence to support the use of topical emollients in reducing the mortality in infants born in developing countries. Well-designed large multicentre randomized clinical trials are urgently needed to guide us on the most appropriate and safe antiseptic to use in neonates undergoing intensive care, especially preterm infants.
Full-text available
To test the effectiveness of an evidence-based clinical practice guideline for neonatal skin care on selected clinical outcomes for newborns in neonatal intensive-care units (NICU), special-care units (SCU), and well-baby nurseries. Prospective evaluation of the collaborative neonatal skin care research-based practice project of the Association of Women's Health, Obstetric and Neonatal Nurses and the National Association of Neonatal Nurses. NICU and well-baby units in 51 hospitals located throughout the United States. Member site coordinators (N = 51) and the neonates (N= 2,820) observed during both the pre- and postimplementation phases of the project. Site coordinators received specialized education in neonatal skin care and implemented an evidence-based clinical practice guideline addressing 10 aspects of neonatal skin care. Baseline observations of skin condition, care practices, and environment of newly admitted neonates were collected by site coordinators. Postimplementation observations were then completed. Skin condition was assessed with the Neonatal Skin Condition Score (NSCS), which ranges from a score of three (best condition) to a score of nine (worst condition), based on dryness, erythema, and skin breakdown. Changes in frequency of selected skin care practices were used to assess the effectiveness and feasibility of using the practice guideline in everyday clinical practice. Aspects of the care environment with potential effect on skin integrity were monitored to determine risk factors. Fifty-one site coordinators made 11,468 systematic assessments of 2,464 NICU and SCU newborns and 356 well newborns. Baseline skin scores were better in well newborns compared with premature newborns. After implementation of the guideline, skin condition was improved, as reflected by less visible dryness, redness, and skin breakdown in both the NICU/SCU and well newborns. The guideline was integrated into care, as evidenced by increased use of emollients, particularly with premature infants, and decreased frequency of bathing. A relationship was shown between selected aspects of the environment and alterations in skin integrity. Use of the AWHONN/NANN Neonatal Skin Care Research-Based Clinical Practice Guideline was successfully implemented at 51 sites, and effectiveness was demonstrated by changed care practices and improved skin condition in premature and full-term newborns. The results of this project support a wider dissemination of the project's practice guideline for neonatal skin care.
Full-text available
Current recommendations for obtaining blood from neonates advise avoidance of the midline area of the heel and are based on postmortem studies. Because of the potential pain and tissue damage from repeated heel pricking in the same area, to investigate using ultrasonography whether the distance from skin to calcaneus is less at the midline than at the borders. One hundred consecutive healthy preterm and 105 consecutive healthy term neonates were studied 48-72 hours after delivery. The skin to perichondrium distance (SPD) was measured on two occasions by ultrasound at the external, midline, and internal areas of the heel. Mean SPD was 0.2 mm less at the midline than at the other sites. The proportion of measurements <3 mm at any of the three sites was the same. Depth was <3 mm in less than 3% of the term and approximately 20% of the preterm infants. The SPD correlated only with gestational age. Of children <33 weeks gestational age, 38% had an SPD <3 mm compared with 8% of older preterm infants. The proportions of preterm infants of > or = 33 weeks gestation and term infants with an SPD <3 mm were similar (8% v 3%). With the use of automated lancets of 2.2 mm length or less, the whole heel plantar surface is safe for obtaining blood in term and preterm infants of > or = 33 weeks gestation. This means that soft tissue damage and pain from repeated pricking in the same area can be reduced.
Safety lancets are used to collect capillary blood samples to test if neonates have rare but serious congenital conditions, such as sickle cell disease, cystic fibrosis, congenital hypothyroidism and inherited metabolic diseases. Blood samples are taken from the heel, but the procedure can cause the neonate pain or discomfort, as well as a risk of local trauma to the nerves and blood vessels, bleeding, infection and scarring. This article explores the need for blood sampling in neonates, discusses the procedure and outlines the types of lancets available. It describes the Neoheel Safety Lancet (Smiths Medical), whose features are designed to avoid pain and trauma during the procedure. Three case studies are included to describe its use in clinical practice.
Background There is a need to choose neonatal heel lance phlebotomy devices with the least potential for pain and post-phlebotomy complications. The purpose of this study was to evaluate two lancet devices (BD's Quikheel and Hawaii Medical's NeatNick) in terms of ease of use and frequency of infant bleeding longer than 5 min.Materials and methodsBetween April 5 and July 15, 2010, phlebotomy staff alternated between using each lancet device on 1243 full term infants at three tertiary care hospitals in Calgary, Alberta.ResultsMore NeatNick than Quikheel subjects bled longer than 5 min post phlebotomy (p < 0.0001). Of eight variables concerning ease of use of the device, seven favoured the Quikheel device and the eighth was not statistically different.Conclusions The Quikheel lancet was preferred over the NeatNick lancet for blood collection in terms of ease of use by phlebotomists and fewer excess bleeding times in newborns.
The heels of 40 children (0.56--13.15 kg), 35 of whom were newborn infants and 28 of whom had 2--20 visible skin punctures, were examined at necropsy, and the thickness of the tissue layers was measured with a metric vernier caliper. Histological examination showed that uncomplicated skin-puncture wounds heal with minimum scarring and no neuroma formation. 1 infant had an infected puncture track extending into the calcaneus and resulting in cellulitis and focal calcaneal necrotising chondritis. The skin's primary blood-supply is located at the junction of the dermis and subcutaneous tissue, and the distance from the surface of the heel to this junction was quite constant (0.35--1.6 mm). However, the distance from the skin surface to the calcaneus increased with infant weight (in the smallest infant it was 2.4 mm), and at the posterior curvature of the heel it was half that from the plantar surface to the calcaneus. The calcaneus rarely extended lateral to a line drawn posteriorly from a point midway between the 4th and 5th toes and running parallel to the lateral aspect of the heel or medial to a line extending posteriorly from the middle of the great toe and running parallel to the medial surface of the heel. Therefore, in order to avoid calcaneal puncture and the risk of osteochondritis, heel puncture in the newborn should be done: (1) on the most medial or lateral portions of the plantar surface of the heel; (2) no deeper than 2.4 mm; (3) not on the posterior curvature of the heel; and (4) not through previous puncture sites that may be infected.
This is updated information on acceptable practice in skin puncture and blood collection in infants, as well as on the devices used, with the additional aim of emphasizing major problem areas and some tentative solutions. Consensus standards for skin puncture have little experimental support, and evade the hard fact that studies are needed to clarify optimum sites for puncture and depth and width of lancets, and to assess the effects of compression and skin resistance in the puncturing process. Preliminary data revealed that the puncturing depth of 2.4 mm recommended for the newborn is excessive. In four of 14 newborns at necropsy, the distance from posterior planar skin surface to underlying bone ranged between 2.0 and 2.2 mm. An experimental lancet, with a 1.8-mm tip length and a diameter of 0.79 mm yielded customary blood volumes from newborns in three of the four pediatric centers where it was tested. Lack of success with the lancet was attributed to inexperienced phlebotomists, not to the lancet's decreased size. Also reviewed are problems with common devices used, and the need for examining the "economy" of blood collection.
To evaluate in a randomised blind study the effect on puncture site lesions of two different incision devices used to obtain blood samples from preterm infants by repeated heel sticks. The neonatal intensive care unit at the Hospital for Children and Adolescents and Laboratory, Helsinki University Central Hospital. A total of 100 preterm infants (birth weight below 2500 g) not previously subjected to heel stick sampling. The infants were randomly allocated to blood sampling from the heel with either a conventional manual lancet or an automatic incision device. The same type of lancet was used for any given baby throughout the study (2-21 days). The damage caused by sampling was evaluated using four criteria: bruising of the heel, inflammation of the heel, bruising of either the ankle or the leg, and skin healing at the puncture site. The evaluation was based on photographs presenting typical categories of each outcome. To obtain a sufficient volume of blood, on average 2.6 times more punctures were needed when the conventional manual lancet was used than when the automatic incision device was used. Heels punctured with the lancet had more bruising (100% v 84%) and more signs of inflammation (79% v 53%), and there was more bruising of the ankle or leg (92% v 53%) than when the automatic incision device was used. Skin healed equally rapidly in the two groups. The use of an automatic incision device for collecting repeated skin puncture samples from preterm infants is less traumatic than the use of a conventional manual lancet.
Capillary blood sampling is an essential method of blood collection performed by nurses of all skill levels to obtain samples for routine laboratory tests in neonates. Accuracy of results depends on proper heelstick and sample collection technique. Recent advances including development of devices designed specifically for heelstick capillary blood sampling and research into expanded safe heel capillary sampling sites are discussed. A step-by-step guide to capillary blood sampling is outlined along with evidence-based practice incorporating neonatal-appropriate disinfection and nonpharmacological analgesia that contribute to improved infant safety and comfort during and after the procedure.
Newborn blood spot sampling
  • C Cavanagh
  • C Coppinger
Cavanagh C, Coppinger C (2009) Newborn blood spot sampling. Infant 5(3): 168-171.