Surgeons are being urged to cut their use of blood transfusions, with experts saying the life-saving but risky procedure is being used unnecessarily.
Rates of blood transfusion use differ noticeably between surgeons, and research indicates some are not careful enough to ensure patients don't bleed unnecessarily during surgery.
A University of Sydney medical school professor, James Isbister, said some doctors were using blood transfusions too freely because they believed them to be benign.
''If [blood transfusion] is not used appropriately it's got more possible complications than other therapies because you are basically doing a transplant,'' he said.
''We have talked about alternatives to transplants for years but … a lot of alternatives shouldn't be alternatives, stopping a patient bleeding is not an alternative.''
Hospital patients who are Jehovah's Witnesses - who refuse blood transfusions on religious grounds - actually do better than other patients.
Studies comparing surgeons have found some used blood transfusions in only 10 per cent of patients, while others used them in 80 per cent of cases.
Blood transfusions put stress on lungs and can cause lung injury and organ failure, as well as potentially having long-term consequences, although the reason is unknown.
On Sunday, Professor Isbister addressed the scientific congress of the Australian Society of Anaesthetists about the issue. He said it was important that patients consulted their GPs before surgery to ensure that they had a healthy blood count.
In 2012-13 governments will spend more than $1 billion on blood and blood-related products, according to the National Blood Authority. Its general manager, Leigh McJames, said that while transfusions can be life-saving, evidence showed up to 20 per cent could be unnecessary in some patient groups.