PREMATURE and sick babies can die from bacterial infections that doctors have missed. But a new way of analysing a baby's heartbeat may spot these infections early enough to save lives.
Bacteria that take advantage of a baby's immature immune system can trigger overwhelming infections called "sepsis". Very underweight babies are twice as likely to die if they have sepsis. Yet cases are often missed because the symptoms can be confusing. Neonatologist Pamela Griffin and cardiologist Randall Moorman from the University of Virginia in Charlottesville examined 89 infants at high risk of sepsis. They found two properties of a baby's heartbeat which could help identify those in distress: temporary, tiny decreases in heart rate, and a reduction of heart rate variability. It is known that very steady heart rates can be a sign of trouble. But no one had noticed these subtle changes in newborns-or linked them to infection. So Moorman and Griffin analysed the length of time between heartbeats. For newborns with sepsis, the chart showed a very regular heart rate between 12 and 24 hours before symptoms appeared.
Griffin suspects that the heartbeat analysis picks up cases of sepsis that blood tests could miss. Reliable, early detection could alert doctors to sick babies and let them start antibiotics earlier. "We're hopeful that we'll be able to save lives," says Griffin.
Author: Nicola Jones
New Scientist issue: 20 January 2001
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