Venipuncture: Using Syringe and Needle

Venipuncture using syringe and needle
The syringe is used in patients with difficult veins. Vacuum tube system preparation procedures are the same for syringe and needle. Blood is gently expelled into a collection tube after withdrawal, avoiding foaming or rupture of the cells by using gentle pressure.

Venipuncture using the infusion set
A syringe and needle or an infusion set (Butterfly) is often used for coagulation studies, for babies and small children with small veins, obese patients with hard to find veins, for scarred veins and for veins other than those in the antecubital fossa. The infusion is used for drawing blood from a patient with small, fragile, rolling veins or in wrist, back of the hand, ankle, foot, or scalp. A 25-gauge needle is recommended for smallest and most fragile veins. A syringe collection system is preferred over evacuated tube system when using 25-gauge infusion set. The infusion set is often used for collecting specimens from pediatric patients. An infusion set is either attached it sterile syringe and manually filling it or by attaching it to an adapter attached to an evacuated tube holder.

Venipuncture from existing intravascular devices or indwelling lines
Devices like indwelling lines or intravascular devices are used for vascular access for extended period of time for administration of therapeutic blood products, or for infusion of fluids, medications, or parenteral nutrition solutions. It is possible to collect venous or arterial blood samples from these devices, but this is only done by well trained experienced phlebotomists. Infection and septicemia are serious consequences in an immunosuppressed patient; strict asepsis control protocol is required for collection from intravascular devices. Each healthcare facility has its own policy and procedure for collection from indwelling lines or intravascular devices.

For collection of blood from intravascular devices, each healthcare facility has its own policy and procedure. Intravascular devices blood collection requires a special training program for phlebotomists. A silicon catheter, and a self healing silicon septum encased in a metal/plastic ports are the main parts of an intravascular device. Under local or general anesthesia, the device is implanted surgically in a patient and the portal is secured to the fascia under the skin and the catheter is tunneled through subcutaneous tissue to a major blood vessel. In the vein the venous port catheters are placed. Attending physicians make the decision to use an intravascular device for obtaining blood specimen.

Venipuncture from Heparin lock
An indwelling ringed butterfly needle is the main constituent of a heparin lock system. Heparin lock system can be used in a vein for 36-48 hours to administer medication intravenously or for collection of blood samples during that time interval. Heparin lock can eliminate multiple punctures, and thus save veins of the patients and decrease the trauma to the veins. Heparin solution of appropriate dilution is injected into the tubing and the solution is kept in place by a plug at the end of the butterfly line.

A needle is a foreign body placed directly into patient’s vein so antibiotic ointment and careful monitoring for inflammation is needed, which are required for adherence to infection control procedures. A waste specimen of 2-3 mL is withdrawn and discarded to remove heparin solution before analysis. Special training and learning to withdraw blood from heparin lock is required for a phlebotomist.

Blood collection for culture.
Blood collected for culture should be free from contamination, so the skin is cleaned three times with povidone iodine solution in a concentric outwardly moving circle. Then povidone iodine is removed with an alcohol pad and aseptic precaution is followed to touch the vein with phlebotomist’s gloved finger. Collection is done in culture bottles using evacuated system. The container tops should be sterilized and dry.

Phlebotomists need to work well with patients and donors (blood donation). Similar to doctors and nurses, a good bedside manner is an important trait for a phlebotomist. These health care professionals also need to be able to draw blood and other fluids from patients without being easily upset. Competencies for phlebotomists also include the ability to get minute samples of blood using finger sticks. Collecting blood from infants through a heel stick is also one of the core competencies for a phlebotomist. Phlebotomist certification ensures that phlebotomists are well trained in these competencies.

Written by Phlebotomy Training specialist Dr Shahbaz A. Cheema, Course Director for Maxis Healthcare who run NHS Accredited Phlebotomy Training courses for medical and non medical practitioners. Learn the 3 Steps To Become a Phlebotomist