25 Aug 2009

Car seats limit kids oxygen supply

Kids should be put in car seats only when travelling, not while sleeping or "hanging out" at home, child health experts warn.

That's because sitting upright in a car seat -- the position that's recommended -- can compress the chest and lead to lower levels of oxygen, according to a new study published in Paediatrics.

"There are people who have no baby beds and have their kids sleep in the car seat all the time," noted one expert, Dr Iley Browning, an associate professor of paediatrics at the Texas A&M Health Science Centre College of Medicine. "That's not a good choice. And dropping oxygen levels are going to get worse when children have colds so you're making your child worse by putting them in a car seat when they're sick. And I guarantee that parents do this more when their child is sick."

But experts agree that the new warning by no means dilutes the message that car seats are critical for protecting children from injury in a collision, just like seat belt restraints protect adults.

"Your child should be restrained properly even for the shortest ride," said Dr Mike Gittelman, an associate professor of emergency medicine and co-director of the Comprehensive Children's Injury Centre at Cincinnati Children's Hospital Medical Center. "You're 88% more likely to be saved in a motor vehicle collision if you're restrained. Car seats save lives."

How the study was done
In addition, Gittelman said, the changes in oxygen saturation detected in the study were "minimal".

Earlier studies on the subject focused primarily on more fragile, preterm infants, he said. But the study's authors noted that airway obstruction in an infant, even if it's mild, has been linked with behavioural problems and lower IQ.

The researchers, from Slovenia and Boston, started looking at healthy newborns when they were two days old, measuring oxygen saturation and other indicators while the infants were in a hospital crib for 30 minutes, a car bed (also known as a "flat car seat") for 60 minutes and a car seat for 60 minutes.

For the 200 infants included in the study, the average oxygen saturation level was 97.9% in the crib, 96.3% in the car bed and 95.7% in the car seat.

Greater differences were seen in average minimal oxygen levels: 87.4% for the hospital crib, 83.7% for the car bed and 83.6% for the car seat.

Children in car seats and car beds spent more time with oxygen levels below 95% than did children in cribs, according to the study. And the longer the child was in the car seat, the worse the respiratory problem became.

Car beds may be safer in this respect than car seats, but even that is not ideal, the study noted. In addition to keeping children out of car seats for long and unnecessary periods of time, the authors suggested that manufacturers consider modifications to the design of the seats.

Many questions still unanswered
"It's important for people to realise that doing some of these things is not benign and has potential risks involved," said Browning, who is also a paediatric pulmonologist at Driscoll Children's Hospital in Corpus Christi, Texas. "Use the car seats when you need to, but otherwise children need to be in a different setting."

The study still leaves many questions unanswered, such as whether the oxygen effect is long-term, said Dr Judy Schaechter, associate professor of paediatrics at the University of Miami Miller School of Medicine and director of the Injury Free Coalition for Kids of Miami.

"Does this go away after a few days or does it last three months," she said. "Clearly, if it turns out to be real, we have to look at manufacturing of car seats."

The study was funded by the Japanese company Aprica, which makes child seats, strollers and other children's products. – (HealthDay News, August 2009)