MONDAY, March 1, 2004 (HealthDayNews) -- Small children placed in booster seats with padded pop-down restraint bars risk being ejected from the seats or suffering a serious chest injury in a crash.
That's the conclusion of a new study in the March issue of Pediatrics.
Compared to standard booster seats that utilize a car's safety belt, the so-called shield-type models pose more than eight times the risk of severe injury to children during an accident, the study found.
"The risk of ejection from the [shield] seat is clear, and that's probably the biggest risk. They are also at increased risk of spinal cord injury and brain damage because of ejection or partial ejection," explains Dr. Marilyn Bull, past chairwoman of the American Academy of Pediatrics' (AAP) Committee on Injury, Violence and Prevention.
Current AAP guidelines mandate that children under 1 year of age and/or 20 pounds ride in infant-only or convertible car seats, positioned so they face toward the rear. Children over that age can be placed in the forward-facing position, but the AAP has for many years stipulated that children over 20 pounds ride in seats that utilize the vehicle's three-point safety straps.
The academy does not recommend the use of booster seats with designs that replace the protection of a safety belt with that of a "shield" -- a horizontal, padded bar roughly in line with the child's mid-torso.
Evidence that children over 40 pounds could too easily be flung out of shield-type booster seats during a crash caused changes several years ago to the U.S. Federal Motor Vehicle Safety Standards. Those new rules mandated that shield booster seats not be used for children over 40 pounds. According to Bull, this ruling "precipitated most manufacturers into removing them from production" during the last five years.
However, thousands of shield-model seats may still be circulating throughout the United States, passed from parent to parent or purchased secondhand.
In the new study, Dr. Elizabeth A. Edgerton and colleagues at Children's National Medical Center in Washington, D.C., compared rates of injury for 46 children weighing between 20 and 40 pounds, brought into emergency rooms after a car accident.
Thirty of the children had been strapped into standard safety-belt booster seats at the time of the crash, while the other 16 had been placed into shield-type models.
Much higher rates of serious injury were found among kids in the shield-type seats compared with those in strap-in models, the researchers report. Children in shield seats were more than eight times as likely to suffer serious injury -- such as brain damage or spinal cord injury -- compared with those belted into conventional child seats. They were also 4.5 times more likely to suffer head trauma and more than five times more likely to be admitted to intensive care, compared to children using strap-in models.
"Many parents are eager to put away the infant car seat and graduate to the relative ease of a booster seat," Edgerton says in a statement. However, she adds, "not all booster seats are equally safe."
Children were especially vulnerable to chest injury during accidents while in the shield booster seats, with risks 29 times those seen in children in belt-type seats. "That would be because of impact against the shield" during the crash, Bull explains.
She also believes too many parents are placing children under 20 pounds in these types of booster seats, adding to the risk. "Yes, the manufacturers recommend them for 20 to 40 pounds, but parents use them for children under 20 pounds," she says.
Bull, who works at Riley Hospital for Children in Indianapolis, has witnessed the tragic results of misused shield-type seats firsthand. "One child that I'm familiar with that came under our care recently was about an 18-month-old child -- too small for that seat." Rushed to the hospital after a crash, she arrived paralyzed and later "died as a complication of her paralysis," Bull says.
The bottom line, experts agree, is that parents should not purchase and use shield-type booster seats. However, if they are already using one, they don't necessarily have to go out and buy another model. Instead, Bull says, the AAP suggests that parents simply "take the shield off and use the seat as a belt-positioning booster."