If necessary, the donor should be asked to open and close his/her hand slowly every 10–12 seconds to encourage a free flow of blood.
The donor must never be left unattended during or immediately after donation and should be kept under observation throughout the phlebotomy.
The blood and anticoagulant should be mixed gently and periodically (at least every 60 seconds) during collection. Mixing should be achieved by manual inversion of the blood pack, or automatically by placing the blood pack on a mechanical agitator or by using a rocking device.
Blood flow should be constantly observed to ensure that the flow is uninterrupted.
The period of donation should not exceed 15 minutes.
The volume of blood withdrawn must be controlled to protect the donor from excessive loss of blood and to maintain the correct proportion of anticoagulant to blood.
The most efficient way of measuring the blood volume in plastic bags is by weight. The mean weight of 1 mL of blood is 1.06 g, and therefore, for example, a unit containing 470 mL of blood should weigh 470 × 1.06 g plus the weight of the pack(s) and the anticoagulant.
If it is not possible to adjust the weighing device in use for the tare weight of the container and anticoagulant solution it is advisable to record the minimum and maximum weight for the brand of pack in use as products from different manufacturers may vary considerably.
Several kinds of weighing equipment are available and such devices should be used according to the manufacturer’s instructions for weighing blood into its plastic pack and periodically calibrated by appropriate techniques.
If used, the pressure cuff must be deflated and the needle then removed from the arm. Immediate pressure must then be applied to the venepuncture site through a suitable clean dressing.
Local procedures must give clear instructions on sealing the pack and removal of the needle for all pack types used. The needle must be discarded into a special container designed to minimise risk to personnel.
The pack must be inverted gently several times to ensure the contents are thoroughly mixed.
The arm and general well-being of the donor should be checked before the donor leaves the session venue.