7- Capillary- Puncture PDF

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CAPILLARY PUNCTURE PMLS 2 LECTURE 6 FINALS LEARNING OBJECTIVES: 1. List and describe the various types of equipment needed for capillary specimen collection. 2. State why it is important to across the fingerprint line. 3. Explain the order of draw for micro collection. 4. List some of the limitations of collecting sites and when each site should be used. 5. Describe the step-by-step procedure of drawing blood by fingerstick and heel stick. TOPIC OUTLINE: a. Equipment I. Micro collection tubes II. Order of draw b. Components of Capillary Blood Test and Reference Values c. Skin Puncture Procedures I. Blood smear II. Filling micro collection tubes III. Filling capillary tubes WHAT IS CAPILLARY PUNCTURE? CAPILLARY PUNCTURE • ______________ or ______________ puncture • method of obtaining one to several drops of blood by puncturing or making an incision in the capillary bed in the dermal layer of the skin with a lancet, other sharp device, or laser • Preferred method for young patients • Infants • Very small children • May also be used for other patients • Obese • Elderly • Severely burned • Point of Care Testing (POCT) in healthcare facility CAPILLARY PUNCTURE EQUIPMENT A. LANCET INCISION DEVICES • Lancet is a sterile, disposable, sharp-pointed or bladed instrument that either punctures or makes an incision in the skin to obtain capillary blood specimens for testing • available in a range of lengths and depths • ______________ use surgical blade

B. LASER LANCET • Vaporizes ____________ in the skin to produce a small hole in the capillary bed without cauterizing delicate capillaries • No sharp instrument is involved • No risk of accidental sharps injury • No need for sharps disposal • Use on the Fingers of adults and children ______________ of age and older C. MICROCOLLECTION EQUIPMENT • also called ______________ and often referred to as “______________” • special small plastic tubes used to collect tiny amounts of blood obtained from capillary punctures • fitted with narrow plastic capillary tubes • have color-coded bodies or stoppers that correspond to color-coding of ETS blood collection tubes • markings for minimum and maximum fill levels that are typically measured in microliters D. MICROHEMATOCRIT TUBES • microhematocrit tubes are disposable • narrow-bore plastic or plastic-clad glass capillary tubes that Fill by capillary action and typically hold ______________ of blood • Used primarily for manual hematocrit (Hct) determination • tubes come coated with ammonium heparin for collecting Hct tubes directly from a capillary puncture or plain when an Hct tube is Filled with blood from a lavender-top tube o Heparin tubes - ______________ band on one end o Non additive tubes - ______________ band E. SEALANTS • Plastic or clay sealants o come in small trays are used to seal one end of microhematocrit tubes • Dry end of the tube was inserted into the clay to plug it (traditional way) F.

CAPILLARY BLOOD GAS (CBG) EQUIPMENT CBG collection tubes • are long thin narrow bore capillary tubes • are normally ______________ for safety • available in a number of different sizes to accommodate volume requirements of various testing instruments • color-coded band identifies the type of anticoagulant that coats the inside of the tube • it is normally ______________, indicating sodium heparin Stirrers • are small metal filings (often referred to as “______________”) or small metal bars that are inserted into the tube after collection of a CBG specimen to aid in mixing the anticoagulant Magnet

has an opening in the center or side so that it can be slipped over the capillary tube and moved back and forth along the tube length, pulling the metal stirrer with it and mixing the anticoagulant into the blood specimen Plastic caps • plastic end caps or closures are used to seal CBG tubes and maintain anaerobic conditions in the specimen •

G. MICROSCOPE SLIDES • occasionally used to make blood films for hematology determinations H. WARMING DEVICE • Important when performing heel sticks on newborns • Increases blood flow as much as seven times • Does not exceed ______________ • Ex: towel or diaper dampened with warm tap water CAPILLARY PUNCTURE PRINCIPLES A. COMPOSITION OF CAPILLARY SPECIMENS • a mixture of arterial, venous, and capillary blood, along with interstitial fluid and intracellular fluid from the surrounding tissues • contains a higher proportion of ______________ than venous blood B. REFERENCE VALUES • Reference (normal) values may differ • ex. the concentration of glucose is normally ______________ in capillary blood specimens, whereas total protein (TP), calcium (Ca2+), and potassium (K+), concentrations are ______________ C. INDICATIONS FOR CAPILLARY PUNCTURE Appropriate choice for adults and older children under the following circumstances: • Available veins are fragile or must be saved for other procedures such as chemotherapy • Several unsuccessful venipunctures have been performed and the requested test can be collected by capillary puncture • The patient has thrombotic or clot-forming tendencies • The patient is apprehensive or has an intense fear of needles • There are no accessible veins • To obtain blood for POCT procedures such as glucose monitoring • Patients who are obese and whose veins are too deep to locate • Patients who are cold and severely dehydrated cannot produce adequate capillary puncture blood sample

Capillary puncture is the preferred method of obtaining blood from infants and very young children for the following reasons: • Infants have a small blood volume • Large quantities removed rapidly can cause cardiac arrest • Obtaining blood from infants and children by venipuncture is difficult and may damage veins and surrounding tissues • Puncturing deep veins can result in hemorrhage, venous thrombosis, infection, and gangrene • An infant or child can be injured by the restraining method used while performing a venipuncture • used for newborn screening tests D. TESTS THAT CANNOT BE COLLECTED BY CAPILLARY PUNCTURE • erythrocyte sedimentation rate methods • coagulation studies that require plasma specimens • blood cultures • tests that require large volumes of serum or plasma E. ORDER OF DRAW The CLSI order of draw for capillary specimens is as follows: • Blood gas specimens (CBGs) • EDTA specimens • Other additive specimens • Serum specimens CAPILLARY PUNCTURE PROCEDURE CAPILLARY PUNCTURE STEPS Step 1: Review and Accession Test Request Step 2: Approach, Identify, and Prepare Patient Step 3: Verify Diet Restrictions and Latex Sensitivity Step 4: Sanitize Hands and Put on Gloves Step 5: Position the patient • Young child is typically held in the lap by a parent or guardian • An infant should be supine (lying face up) with the foot lower than the torso Step 6: Select the puncture/Incision site General site selection criteria: • one that is warm, pink or normal color, and free of scars, cuts, bruises, or rashes • it should not be cyanotic (bluish in color), edematous (swollen), or infected • swollen or previously punctured sites should be avoided A. Adults and Older Children: • palmar surface of the distal or end segment of the middle or ring finger of the nondominant hand • should be in the central, fleshy portion of the finger, slightly to the side of center and perpendicular to the grooves in the whorls (spiral pattern) of the fingerprint B. Infants: • heel for less than ______________ • perform in an area of the heel with little risk of puncturing the bone • Complications: osteomyelitis, osteochondritis, and infection...