Schedules of routine shipments of blood components are agreed upon by hospital blood banks and suppliers, depending on the inventory needs of a given hospital. These shipments are usually set up on a weekly basis, but for larger hospital centers may be daily. Product shipments are also affected by the proximity of the hospital to the supplier as well as by the blood component's shelf life; plasma may require fewer shipments because it can be stored frozen for up to 12 months while platelets, stored at room temperature, typically must be used within a one- to three-day time period and require more frequent shipments. RBCs (red blood cells), though able to be stored refrigerated for a few weeks, usually also require frequent deliveries due to their heavier use. Non-scheduled, supplemental shipments are ordered by hospital blood banks when additional components are urgently needed.
Ever since the beginning of the AIDS epidemic 20 years ago, there has much more focus on appropriate use of blood in addition to the safety of the blood supply. National medical organizations and some regulatory agencies have set forth clinical guidelines for appropriate indications for transfusion of blood components. Escalating costs and blood shortages have also prompted greater scrutiny of blood usage by hospitals.
At the federal level, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) requires hospitals to monitor and review blood usage by its physicians. The JCAHO has also mandated informed consent prior to blood transfusion (excluding emergency situations).
Use of blood, though, is still predominantly left up to the discretion of the physicians who are treating the patients, but physicians' transfusion practices can vary widely depending on their level of knowledge and interest (many physicians receive little academic training in blood component therapy), area of specialty (e.g., a hematologist vs. other specialist), and, possibly, the setting in which they practice (e.g., an academic institution vs. a community hospital).
That there is a range of transfusion practices is not unexpected since the guidelines for blood transfusion are not yet that clear-cut, there are few published randomized-controlled studies, and laboratory tests used to estimate the need for blood replacement are imprecise. Nevertheless, most physicians are recognizing the shift to more conservative transfusion practices, partly based on case studies of Jehovah's Witness patients whose religious beliefs preclude use of blood components.
Advances in medical therapy including improved surgical and anesthetic techniques that reduce blood loss, use of cell savers that salvage lost blood during surgery, and development of medications that stimulate bone marrow to regenerate blood cells have also helped to curtail blood use.