Venous blood is obtained from a vein by venipuncture. Venous blood can also be obtained from central access devices. Institutional policy determines the sampling procedure from central access devices. The site selected is dependent on the sample volume needed for analysis. Finger or heel sticks can collect approximately 0.2-0.5 mls of blood.
Venipuncture is used when multiple tubes with different anticoagulants are needed.
Blood Collection Devices Finger or heel stick devices - a number of devices are available including retractable lancets, straight lancets and needle tip devices. The retractable lancet is used most often for safety reasons. The retractable lancet is spring loaded, the lancet retracts into the body of the device after skin puncture. All lancets are sterile and for one time use only. Needles for venipuncture- Needles are available in many gauges and lengths.