Types of punctures

1. Types of punctures By Dr Fatehia Awny Faculty of Health Sciences . BAU 2015

2. Skin puncture Earlobe puncture. Types of punctures : Finger puncture heel stick

3. for patients in whom venous access is difficult, when small quantities of blood are sufficient for testing. In newborns, heel sticks are the preferred collection method for small volumes of blood. Why Perform a Skin Puncture?

4. Capillary collections may be preferable over venipuncture : Severely burned patients Obese patients Patients with thrombotic tendencies Elderly patients or others in whom superficial veins are very fragile or inaccessible Patients performing self-testing Point-of-care testing Newborn testing Patients who have a paralyzing fear of needles Differences Between Skin Puncture Blood and Venipuncture Blood!!!!!!!!!!!!!!!!!!!!!!!

5. finger puncture: Preparation for finger stick Place all collection materials on top of disposable pad. Open the lancet, alcohol swabs, gauze, bandage, and other items. Have all items ready for blood collection.

6. finger puncture: Choose the finger carefully Best locations for a finger stick is the 3rd and 4th fingers of the non-dominant hand. Avoid the 2nd and 5th fingers if possible. Perform the stick off to side of the center of the finger. NEVER use the tip or center of the finger.

7. finger puncture: Massage or Warm the site Avoid fingers that are cold, cyanotic, swollen, scarred or covered with a rash. Massage to warm the finger and increase blood flow by gently squeezing from hand to fingertip 5-6 times.

8. finger puncture: Clean and DRY the site Cleanse fingertip with 70% isopropyl alcohol Wipe dry with clean gauze or allow to air dry. Caution: Alcohol can falsely elevate or lower blood glucose results.

9. finger puncture: Hold the finger in an upward position and lance the finger (across the fingerprint) between the side and the pad with the proper size lancet (adult/child). Press firmly on the finger when making the puncture. Doing so will help you to obtain the amount of blood you need.

10. finger puncture: Finger Stick location Using a sterile lancet, make a skin puncture just off the center of the finger pad. Wipe away the first drop of blood (which tends to contain excess tissue fluid).

11. Apply slight pressure to start blood flow. Blot the first drop of blood on a gauze pad and discard in appropriate biohazard container. finger puncture:

12. Keep the finger in a downward position and gently massage it (but do not “milk”) to maintain blood flow. finger puncture:

13. summary

14. If child is <12 months of age, the lancet must have a depth of 2 mm or less , and a fingerstick MAY NOT be performed – must do a heel stick instead

15. The heel is used for dermal punctures on infants less than 1 year of age because it contains more tissue than the finger, and has not yet become callused from walking. No nerves ,bones or tendons near by Why heel stick?

16. Hatched areas (arrows) indicate safe areas for puncture site. heel stick:

17. Warm site with soft cloth moistened with warm water (up to 41 o C) for 3 – 5 minutes. heel stick:

18. Cleanse site with alcohol prep. Wipe DRY with sterile gauze pad. heel stick:

19. Puncture heel. Wipe away first blood drop with sterile gauze pad. Allow another LARGE blood drop to form. heel stick:

20. Mainly used for bleeding time . Principle The bleeding time is the time it takes for a small standardized wound, introduced into the capillary bed of the finger or earlobe,to stop bleeding. It is dependent upon: 1- the elasticity of the skin and capillary vessels, 2-the efficiency of the tissue fluids 3-the mechanical and chemical action of the thrombocytes (blood platelets). Earlobe puncture:

21. Make a small wound 3 mm deep in the lateral aspect of a fingertip or the lower portion of the ear lobe, using a suitable lancet. The wound should be sufficiently deep to give a free flow of blood without squeezing. Start the stop watch immediately after the puncture is made. Though the stop watch is started a few seconds after puncturing the skin, very little error results in the bleeding time.3. At intervals of one-half minute gently blot the blood from the wound with a piece of filter paper, being careful not to touch the skin.4.   Earlobe puncture:

22. The interval of time between the puncture and the cessation of bleeding is the bleeding time. The blood should fail to appear on the filter paper in 1-3 minutes. All abnormal findings should be rechecked. NORMAL : 1-3 minutes Earlobe puncture:

23. Specimen Types Blood Proper collection vial Collection comprised of two bottles: Aerobic Anaerobic 25

24. Blood culture bottles. 26

25. Specimen Types 29

26. Phlebotomy Phlebotomy procedure Important to all laboratory testing Sample’s quality determines accuracy of its final result Anticoagulant Mixed with blood to prevent coagulation Three anticoagulants are used in the hematology laboratory 30

27. Phlebotomy Anticoagulant EDTA – prevents coagulation by chelating Ca 2+ Use for tests: CBC, Hct, Plt, Retic, peripheral blood smear examination, flow cytometry Sodium citrate – prevents coagulation by binding Ca 2+ Used for coagulation studies Lithium heparin – prevents coagulation by interacting with antithrombin Used for osmotic fragility: not appropriate for routine hematology testing 31

28. Equipment Sample collection tubes Evacuated sample collection tubes Sterile Color coded to indicate type of anticoagulant present or the lack of anticoagulant Only small amounts of sample for analysis necessary Interior of a sample collection tube is a vacuum Capillary punctures Microcollection tubes Do not contain a vacuum 32

29. Capillary Puncture Collection tubes Should be properly labeled with patient’s name, unique ID number, date, and time of collection 33

30. Specimen Collection Anticoagulant of choice Sodium citrate, 3.2% Ratio of anticoagulant : whole blood is 1:9 > 55% hematocrit Smaller volume of plasma relative to citrate Excess free citrate binds calcium in the test procedure Falsely prolonged clotting times Adjust citrate concentration Citrate tubes are available that draw 4.5 mL, 2.7 mL, 1.8 mL 34

31. Specimen Collection Anticoagulant to blood ratio 1:9 ratio critical for valid results If under-filled – ↑ citrate, bind calcium in test procedure Falsely prolonged test results If overfilled – insufficient calcium bound Clotting can occur in tube Falsely prolonged results Accurate labeling of tube Include pre-or postinfusion, time of draw 35

32. Specimen Collection Specimen draw time Check patient history of receiving blood products If testing done within the half-life of administered clotting factor then test may measure transfused component as well as the patient's component Fibrinolytic factors – diurnal variability Platelet studies – medication history 36

33. Specimen Processing Plasma for coagulation testing Citrated whole blood is centrifuged Platelet-poor plasma (PPP) Platelet-rich plasma (PRP) 37

34. Specimen Processing Platelet-poor plasma Citrated specimen centrifuged for 15 minutes at 2500xg < 10 x 10 9 /L platelets Depending on coagulation instrumentation Leave plasma on top of packed cells or Remove plasma with plastic pipette – plastic tube with cap Leave small amount of plasma on top 38

35. Specimen Processing Use platelet-poor plasma because Platelets contain PF4 Neutralizes heparin Platelets contain phospholipids Affect LA testing and factor assay testing Platelets contain proteases Alter results for von Willebrand testing Any clot in specimen Specimen unacceptable After removing PPP, twirl applicator stick in packed cells to detect clots 39

36. Specimen Processing Platelet-poor plasma Separated plasma Stored at 18-24°C or 2-8°C for up to 4 hours If testing is delayed > 4 hours Stored at -20°C for up to 1 week Stored at -70°C for up to 6 months 40

37. Specimen Processing Platelet-poor plasma Frozen specimens Thawed rapidly at 37°C Excessive heating can destroy Factor V and VIII Never store in self-defrost freezers Special testing may require special collection and storage procedures 41