How can autologous blood transfusions help our patients?

In modern day clinical nursing practice, respecting and encouraging patient autonomy, together with acting as advocate for the patient, is an integral part of holistic patient care. We have a 'duty of care' to our patients. So why, in the early days of the 21st century, are we still transfusing our patients with homologous blood products when there is a safer alternative which has been recognised for almost 200 years?