For critically ill children, fresh blood transfusions may be no better than blood that has been stored for several weeks.

Transfusions in seriously ill children are usually given to improve oxygen delivery and prevent organ failure, and some studies have suggested that newer blood is better. Now a blinded, randomized trial has found it is not.

Researchers in 50 hospitals in the United States and five other countries randomized 1,538 children, average age 1.8 years, to receive either blood that was less than a week old, or the standard-issue blood. That blood was an average of 18 days old, and in a few instances as old as 35 to 41 days.

Over the next month, they found there was no difference between the two groups in new, progressive or multiple organ failure, blood infections, acute respiratory distress or mortality.

Cut blood pressure and dementia risk

The benefits of reducing blood pressure to lower the risk for cardiovascular disease are well known, but the role of blood pressure control in dementia has been less certain. Now pooled data from six large observational studies suggests that antihypertensive medicines may lower the risk for Alzheimer's disease and other forms of dementia. The review is in Lancet Neurology.

The studies involved more than 31,000 participants older than 55, with follow-ups ranging from seven to 22 years.

Among the 15,537 people with high blood pressure, those using antihypertensive medicine had a 12% reduced risk for dementia and a 16% reduced risk of developing Alzheimer's disease. The 15,553 people with normal blood pressure had the same risk for dementia as those who controlled their blood pressure with medicine. The type of medicine used made no difference.

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