Thousands of patients facing routine surgery could have their operations cancelled under a national plan to protect the blood supply during shortages.
Hospitals have been told to draw up lists of procedures that might be delayed in an attempt to ensure transfusions could continue for those whose life was threatened by accidents, heart disease and organ failure.
Officials at the Department of Health and National Blood Service have warned that uniform arrangements are needed across England and north Wales to ensure that blood remains available to those who most need it.
Emergencies could be sparked either by bad weather or flu epidemics reducing donations or by terrorist attacks. Any of these incidents could cause an urgent demand for more blood to help people injured and spark such chaos that regular collection of blood was disrupted.
Longer-term problems might also arise if the NHS is forced to further reduce its pool of donors to limit the risk of them accidentally infecting others. Fears of human BSE infection have already forced big changes in transfu sion practice. Most hospitals keep about three days' supply of blood and call in more from the blood service as needed. But that might be reduced to as little as one and a half days under staged responses to the emergency plan.
Blood is only usable for five weeks after donation, so even short interruptions to donations could badly affect the supplies required.
The plan, sent in outline to hospital managers last week, is the most vigorous attempt to shame hospitals into using less blood, even before emergencies arise.
More than 2m units - a unit is around a pint - are donated by 1.65 million people each year. But experts believe nearly a fifth of that total is used inappropriately.
The pool of donors is falling and reaction to previous attempts to use blood more wisely has been patchy. Some hospitals have successfully reduced usage and persuade more people facing routine operations to donate their own blood in advance.
Some also use a process called cell salvage in which blood lost by a patient during an operation is "scrubbed" clean of impurities and transfused back while surgery continues.
Hospitals that have not done as well introducing such measures would have to contribute most to reducing blood use during less serious shortages.
Even when the required reduction in blood usage was quite small, however, some might have to consider cancelling any routine surgery where there was a 20% chance of patients needing more than two units of blood. This would inevitably immediately in crease hospital waiting lists. As shortages got more serious, other surgery would be hit, including that bringing pain re lief to cancer sufferers, along with transfusions for people who had serious, but not life-threatening, anaemia.
In crises where more than 50% of blood supply was cut, only emergency operations and cancer treatments where a cure was probable would continue. Even planned stem cell transplants or chemotherapy should be delayed.
