Phlebotomy: Tourniquet Application

Preparing for Venipuncture

• When applying a tourniquet, it should be tight enough to assist in finding the vein but not so tight that it slows or stops blood flow, and it should be removed quickly and easily, within 1 minute after application.
• If a tourniquet is not available, a blood pressure cuff pumped to 40 mm/Hg can be used as an alternative.
• The tourniquet should be placed approximately 3 to 4 inches above the antecubital area for collections in that region, or above the wrist bone for dorsal hand collections.

Observing and Palpating

• When palpating, start from the middle of the antecubital region and move towards the outside of the arm, using light pressure and a single finger (preferably the index or second finger of the non-dominant hand).
• Veins feel spongy and bouncy, while tendons feel hard and should be avoided.
• Avoid veins that feel hard, as they may be sclerosed or scarred.
• Select a vein that is well-anchored, feels spongy and bouncy, is straight, and is easy to access with a needle.

Selecting and Preparing the Site

• Observe the patient's arm for any factors that can affect the blood collection, such as tattoos, scarring, or hematoma.
• Ask the patient which arm they prefer to use for the collection, and start palpation on that arm.
• Avoid using the arm on the affected side of a patient who has a history of a mastectomy, and avoid areas with tattoos or hematoma.
• Check the requisition to know what supplies are needed, and gather all necessary supplies before the blood collection.

Tourniquet Application and Removal

• Tourniquets can be for single or multiple use, and should be inspected for contamination, cracks, or excessive wear before each patient.
• Remove the tourniquet gently, as the needle will still be in the vessel.
• Discard or reuse tourniquets as the facility requires.

Equipment Selection

• The evacuated tube system (ETS) is the most commonly used equipment for venipuncture.
• Equipment used for ETS includes gloves, isopropyl alcohol swabs or pads, and gauze pads.
• Gloves should be new and well-fitting, and should be used for each patient venipuncture.
• Isopropyl alcohol swabs or pads should be used to cleanse the skin before inserting the needle, and should be discarded after each use.
• Gauze pads should be disposable and used to provide pressure to aid in clotting and to cover the venipuncture site.

Objectives

• Upon completion of this chapter, you should be able to determine the appropriate supplies and equipment needed for the requested collection, verify the quality of the supplies and equipment, select the appropriate collection site, apply and remove the tourniquet, prepare the collection site, and perform proper insertion and removal techniques for venipuncture.

Applying a Tourniquet

• Apply the tourniquet so that removal is quick and easy, and remove it once blood flow is established, no longer than 1 minute after application.
• A tourniquet that is too tight can slow or stop blood flow and cause patient discomfort.
• If a tourniquet is not available, a blood pressure cuff pumped to 40 mm/Hg can be used.

Palpation

• Start palpating from the middle of the antecubital region and move outward, using light pressure and the very tip of the index or second finger of the nondominant hand.
• Veins feel spongy and bouncy, while tendons feel hard and should be avoided.
• Avoid palpating with the thumb and do not select a vein that can be seen but not felt, as it may be a superficial vessel.

Choosing a Vein

• The ideal vein is well-anchored, feels spongy and bouncy, is straight, and is easy to access with a needle.
• The basilic vein is the last choice due to the proximity of the radial nerve and brachial artery.
• Never reposition the needle if an attempt to collect blood from the basilic vein is unsuccessful.

Special Considerations

• For infants, use the heel for blood collection up to 12 months of age, avoiding areas with hematomas, recent access, or cuts/scratches.
• For dermal puncture in children or adults, use the middle and ring fingers of the nondominant hand, avoiding areas with scarring, cuts, or calluses.

Tourniquet Maintenance

• Inspect multiple-use tourniquets for contamination, cracks, or excessive wear before each use.
• Dispose of single-use tourniquets after use and multiple-use tourniquets with defects or contamination.

Site Selection and Preparation

• Observe the patient's arm for factors that can affect blood collection, such as tattoos, scarring, or hematomas.
• Ask patients about their preferred arm for collection and avoid using the arm affected by a mastectomy or covered with a tattoo.
• Check individual packages of alcohol pads for rips or tears, and dispose of any defective or dry pads.