Atlas of Procedures in Neonatology, 4th Edition

Blood Sampling



Dawn M. Walton

Billie Lou Short

  1. Indications
  2. Blood sampling
  3. Routine, particularly if a large volume of blood is needed
  4. Blood culture
  5. Central hematocrit
  6. Preferred (over capillary sample) for certain studies (1,2 and 3)
  7. Ammonia (arterial optimal)
  8. Drug levels
  9. Cross-matching blood
  10. Hemoglobin/hematocrit
  11. Karyotype
  12. Lactate and pyruvate levels (arterial optimal)
  13. Administration of drugs
  14. Contraindications
  15. Use of deep vein in presence of coagulation defect
  16. Local infection at puncture site
  17. Femoral or internal jugular vein (see G)
  18. External jugular vein in infants with respiratory distress, intracranial hemorrhage, or raised intracranial pressure
  19. Precautions
  20. Observe universal precautions. Wear gloves.
  21. When sampling from neck veins, place infant in head-down position to avoid cranial air embolus. Do not use neck veins in infants with intracranial bleeding or increased intracranial pressure, except as a last resort.
  22. Remove tourniquet before removing needle, to minimize hematoma formation.
  23. Apply local pressure with dry gauze to produce hemostasis (usually 2 to 3 minutes).
  24. Avoid using alcohol swab to apply local pressure (painful, impairs hemostasis).
  25. Special Considerations for Neonates
  26. Conserve sites to preserve limited venous access by using distal sites first whenever possible.
  27. Use small needle or scalp vein butterfly. A 23-gauge needle is best. Hemolysis or clotting may occur with a 25 gauge or smaller.
  28. Choice of veins (Fig. 13.1) in order of preference:
  29. Antecubital fossa
  30. Dorsum of hands
  31. Dorsum of feet
  32. Greater saphenous vein at the ankle
  33. Vein in center of the volar aspect of the wrist
  34. Scalp
  35. Proximal greater saphenous vein
  36. Neck
  37. Recent studies show that adequate pain control can be achieved during venipuncture with EMLA (Astra Pharmaceuticals, L.P., Wayne, PA, USA) cream applied 1 hour prior to procedure, if time allows (4,5).
  38. Oral sucrose solution (24% to 25%) provides quick and effective pain control for venipuncture (6,7).
  39. Heel lancing can be more painful and require more punctures than venipuncture in infants (4,8).
  40. Equipment
  41. Gloves
  42. A 23- to 25-gauge venipuncture needle (a safety-engineered needle should be used) (Fig. 13.2).
  43. Syringe with volume just larger than sample to be drawn
  44. Prepared alcohol swabs
  45. Gauze pads
  46. Appropriate containers for specimens
  47. For blood culture:
  48. Povidone-iodine solution preparation (three swabs)
  49. Sterile gloves
  50. Blood culture bottle(s)
  51. Transfer needle
  52. Tourniquet or sphygmomanometer cuff



FIG. 13.1. The superficial venous system in the neonate.




FIG. 13.2. Safety-engineered needles for venipuncture.

  1. Technique (See Procedures DVD for Video)

General Venipuncture

  1. Locate the appropriate vessel. Use transillumination if necessary (see Chapter 12). Warm extremity with heel warmer or warm washcloth if circulation is poor.
  2. Apply anesthetic cream if time permits, and/or administer sucrose solution if possible.
  3. Restrain infant appropriately.
  4. Prepare area with antiseptic (see Chapter 4).
  5. Occlude vein proximally using either:
  6. Tourniquet or cuff inflated to level between systolic and diastolic pressure (Fig. 13.3)
  7. Direct pressure over vessel
  8. Rubber band (loop two bands together, tied as in Fig. 13.3)

FIG. 13.3. Correct application of a tourniquet for quick release.

  1. P.87

FIG. 13.4. Anterior wall of vein removed. Needle penetrating skin a short distance from site of venipuncture.

  1. Remove occlusion device and replace to promote optimal vein distension.
  2. Check syringe function and attach to needle. Alternative method is to use Microlance needle (0.9 x 40 mm) (Becton Dickinson, Franklin Lakes, NJ, USA) without a syringe to collect samples by drip method. Drip method cannot be used for blood culture or coagulation studies (8).
  3. Penetrate skin first and position for entry of vein (Fig. 13.4).
  4. Angle of entry 25 to 45 degrees
  5. Bevel up preferred for optimal blood flow (less chance of needle occlusion by vein wall)
  6. Direction of entry with or against direction of blood flow
  7. If possible, insert needle at area where vessel bifurcates to avoid “rolling” of veins.
  8. Collect sample by gentle suction
  9. To prevent occlusion by vein wall
  10. To avoid hemolysis
  11. If Microlance needle is used, collect sample by drip directly into specimen container.
  12. Release tourniquet.
  13. Remove needle and apply local pressure with dry gauze for 3 minutes or until complete hemostasis.

FIG. 13.5. A: Anatomy of the femoral triangle as defined in the text. (Adapted from 

Plaxico DT, Bucciarella RL. Greater saphenous vein venipuncture in the neonate. J Pediatr. 1978;93:1025

, with permission.) B: Position of the femoral triangle on the abducted thigh.

Scalp Vein

  1. Shave adequate area of frontal or parietal scalp.
  2. Use scalp vein needle set or 23-gauge butterfly.
  3. Occlude vein proximally with finger, or place a rubber band around head circumference, avoiding eye area.
  4. Feel for a pulse to avoid tapping an artery.
  5. Use a shallow angle (15 to 20 degrees).
  6. See technique for general venipuncture.

Proximal Greater Saphenous Vein (9)

  1. Have assistant hold infant's thighs abducted with knees and hips slightly flexed.
  2. Locate femoral triangle (Fig. 13.5A).



  1. Proximal boundary: inguinal ligament
  2. Lateral boundary: medial border of sartorius muscle
  3. Medial boundary: lateral border of adductor longus muscle
  4. Enter skin and then vein at point approximately two-thirds along line from inguinal ligament to apex of triangle (Fig. 13.5B).
  5. Use relatively steep angle (60 to 90 degrees).
  6. After entering skin, advance while applying gentle suction 1 to 4 mm until blood return is achieved.
  7. See F, “General Venipuncture.”

External Jugular Vein

  1. Position infant in head-down position with head extended and rotated away from selected vessel (Fig. 13.6).
  2. Prepare skin over sternocleidomastoid muscle with antiseptic.
  3. Flick infant's heel to induce crying and optimize vein distension.
  4. Visualize external jugular vein running from angle of jaw to posterior border of sternocleidomastoid in its lower third.
  5. Puncture vessel where it runs across the anterior border of the sternocleidomastoid muscle.
  6. See F, “General Venipuncture.”

FIG. 13.6. Infant positioned for puncture of external jugular vein.

  1. Complications (10,11,12 and 13)
  2. Hemorrhage with
  3. Coagulation defect
  4. Puncture of deep vein
  5. Venous thrombosis or embolus, with puncture of large, deep vein (11)
  6. Laceration of adjacent artery
  7. During femoral vein puncture:
  8. Reflex arteriospasm of femoral artery with gangrene of extremity (12)
  9. Penetration of peritoneal cavity
  10. Septic arthritis of hip (13)
  11. During internal jugular puncture:
  12. Laceration of carotid artery
  13. Pneumothorax/subcutaneous emphysema
  14. Interference with ventilation owing to positioning for jugular vein puncture
  15. Raised intracranial pressure owing to head-down position aggravating intraventricular hemorrhage
  16. During scalp vein puncture:
  17. Laceration of artery
  18. Corneal abrasion or other eye damage if rubber band used improperly


  1. Baral J.Use of a simple technique for the collection of blood from premature and full-term babies. Med J Aust. 1968;1:97.
  2. Shohat M.Preterm blood counts vary with sampling site [Letter]. Arch Dis Child. 1987;62:1193.
  3. Thurlbeck SM, McIntosh N.Preterm blood counts vary with sampling site. Arch Dis Child. 1987;62:72.
  4. Shah VS, Taddio A, Bennett S, et al. Neonatal pain response to heel stick vs venipuncture for routine blood sampling. Arch Dis Child Fetal Neonat Ed.1997;77:F143.
  5. Larsson BA, Tannfeldt G, Lagercrantz H, et al. Alleviation of the pain of venipuncture in neonates. Acta Paediatr.1998;87:774.
  6. Archarya AB, Annamali S, Taub NA, Field D.Oral sucrose analgesia for preterm infant venipuncture. Arch Dis Child Fetal Neonat Ed. 2004;89:F17.
  7. Stevens B, Yamada J, Ohlsson A.Sucrose for analgesia in newborn infants undergoing painful procedures. Cochrane Database Syst Rev. 2004;(3):CD001069.
  8. Larsson BA, Tannfeldt G, Lagercrantz H, et al. Venipuncture is more effective and less painful than heel lancing for blood tests in neonates. Pediatrics.1998;101:882
  9. Plaxico DT, Bucciarelli RL.Greater saphenous vein venipuncture in the neonate. J Pediatr. 1978;93:1025.
  10. McKay RJ Jr.Diagnosis and treatment: risk of obtaining samples of venous blood in infants. Pediatrics. 1966;38:906.
  11. Nabseth DC, Jones JE.Gangrene of the lower extremities of infants after femoral venipuncture. N Engl J Med. 1963;268:1003.
  12. Kantr RK, Gorton JM, Palmieri K, et al. Anatomy of femoral vessels in infants and guidelines for venous catheterizations.Pediatrics.1989;33:1020.
  13. Asnes RS, Arendar GM.Septic arthritis of the hip: a complication of venipuncture. Pediatrics. 1966;38:837.