Current guidelines for heart and breathing rates in children are inaccurate and not based on evidence, researchers have claimed.

The study, based on data collected from more than 140,000 children, discovered that vital signs change as children develop, and are different to those that doctors would currently go by.

Researchers claimed that the current guidelines have been passed down from one generation of doctors to the next, but are not evidence-based. According to the study, it would mean more than half of 10-year-olds would be diagnosed with abnormal vital signs.

The study showed that, on average a one-month-old would have a heartbeat rate of 145 beats per minute - but a two-year-old  would have 113 beats per minute. The rate of breathing and heartbeat are important tools for diagnosing illnesses.

The authors of the report, which appeared in the Lancet, have instead published new charts showing healthy vital signs at different ages.

Dr Matthew Thompson, from the University of Oxford, said: "Children with fast heart rates are not being picked up and some are being diagnosed with a fast rate when they're normal.

"Our findings suggest that current consensus-based reference ranges should be updated with new thresholds on the basis of our proposed centile charts, especially for those age groups where there are large differences between current ranges and our centile charts, indicating that many children are likely to be misclassified."

Posted by Robert Mair on 15.3.11 Comment on this article by sending it to: penny.hosie@pavpub.com