Chapter 10 Capillary Puncture Equipment and Procedure Lancet Site Grip

OBJECTIVES Define the key terms and abbreviations listed at the beginning of this chapter. List and describe the various types of equipment needed to perform skin puncture. State the composition of skin puncture blood, identify which tests have different reference values when collected by skin puncture methods, and name tests that cannot be performed by skin puncture. State indications for performing skin puncture on adults, infants, and children.

OBJECTIVES Describe the proper procedure for selecting a skin puncture site and indicate precautions associated with site selection. Describe the proper procedure for collecting skin puncture specimens from adults, infants, and children. List the order of draw for collecting skin puncture specimens. Describe the procedure for making both routine and thick blood smears and reasons for making them at the collection site.

72. List 4 Capillary puncture equipment Lancets Finger-stick lancets laser lancet – Children > 5 yrs Heel-stick lancets—special depth to prevent injury

Skin Puncture Equipment (continued Collection Devices Micro-collection containers Micro-hematocrit tubes

Skin Puncture Equipment (continued) Plastic/Clay Sealant Capillary Blood Gas Collection Equipment Micropipet Dilution System Warming Devices

Skin Puncture Equipment (continued) Micro-hematocrit tubes Notice improper technique!!!!

73. A capillary specimen is a mixture of -arterial, venous and capillary blood Interstitial fluid ( fluid in the tissue spaces between cells. Intracellular fluid ( fluid within cells) from surrounding tissue.

74. Which test(s) is higher or lower due to this specimen type? Reference (normal) values for skin puncture blood higher in skin puncture blood glucose lower in skin puncture blood total protein calcium potassium

75. List 4 reasons for adults & older children to get a capillary puncture no accessible veins to save veins for chemotherapy clotting tendencies home-testing procedures

Indications for performing skin puncture (continued) Infants & Children venipuncture too difficult may damage veins chance of injury when restrained large quantities of blood removed may lead to anemia

Skin Puncture Site Selection Criteria General criteria Site should be warm, normal color, and free from scars, cuts, bruises, or rashes do not choose cold, cyanotic, or edematous Infants Older children and adults

Site Selection for Infants Heel Recommended site Plantar surface of the heel Medial or lateral High risk areas Calcaneus Osteomyelitis Osteochondritis Posterior curvature

76. When is a capillary puncture preferred? It Depends upon: - amount of blood required - test(s)

77. What is the “Order of Draw” for capillary puncture? EDTA tubes—minimize clotting and effects on cells for CBC Other additive specimens Serum specimens

78. List 7 “Do Not’s” for a capillary puncture, from adults or older children Side of a mastectomy Infant or child, under 1 yrs. (bone injury likely) Side or very tip – (bone vs skin) Index finger – (sensitive / calloused) Ring or little finger – (bone vs skin likely) Thumb – has pulse Parallel to grooves – won’t get a tear droplet

79. List 7 “Do Not’s for an infant capillary puncture Earlobes Deeper than 2.0mm (bone injury) Previous sites (painful, infection) Between imaginary borders Posterior curvature (bone close to surface) Arch, other foot area ( arteries, nerves, tendons, cartilage) Bruised ( painful, impaired circulation, by products can affect the specimen

Heel Puncture Precautions Do not puncture deeper than 2.0 mm Do not puncture through previous punctures Do not puncture the area between imaginary boundaries Do not puncture the posterior curvature of heel Do not puncture in the arch Do not puncture areas of the foot other than the heel

Skin Puncture Principles

80. What must be done for all “Heel” stick prior to the puncture? Warm the Site (dilates capillaries)

81. What does “PKU” indicate and explain the importance of this test Phenylketonuria - presence of certain genetic metabolic (chemical changes within living cells) either hormonal and functional disorders, which can lead to mental handicaps if not detected. PKU, hypothyroidism – required by law for all newborns

Newborn Screening PKU Hypothyroidism Neonatal Bilirubin Collection Result of defect in enzyme that converts phenylalanine to tyrosine Cannot be cured,but treated If untreated can lead to brain damage Hypothyroidism Inherited and noninherited forms Positive results are confirmed by TSH levels Treated with missing thyroid hormone Neonatal Bilirubin Collection To detect & monitor increased bilirubin levels associated with HDN Abnormal liver function

Special Skin Puncture Procedures (continued) Newborn Screening To test for the following genetic or inherited diseases (state specific)—usually will use blood droplet on specially designed filter paper PKU Hypothyroidism Galactosemia Homocystinuria Maple syrup urine disease Sickle cell

Example of a Newborn Screening Policy Here is some sample content from Newborn Screening (NBS):       POLICY: Newborns will have a screening for metabolic disorders prior to discharge. GENERAL INSTRUCTIONS: All newborns will have a screen drawn per the following criteria: Hours of age; recommend as close to 24 hours as possible Do not do a newborn screening on babies that are less than 12 hours old………………………………………

More congenital diseases Miscellaneous multisystem diseases Cystic fibrosis (CF) > 1 in 5,000 Congenital hypothyroidism (CH) > 1 in 5,000 Biotinidase deficiency (BIOT) > 1 in 75,000 Congenital adrenal hyperplasia (CAH) > 1 in 25,000 Classical galactosemia (GALT) > 1 in 50,000

Tests that cannot be performed by skin puncture Erythrocyte sedimentation rate (ESR) Coagulation studies that require plasma Blood cultures Tests that require increased volumes of serum or plasma