Heart surgery preparation. Gloved hands using a syringe to draw blood out of a patient's neck and to flush a tube with blood prior to heart surgery. The clear tubes all lead to a line (upper right) going into a blood vessel in the patient's neck. They will be used to deliver anaesthetic and other drugs, to supply blood, or to take blood samples. This must not be done until the tubes are flushed with blood to remove the air inside them.