Children as young as 9 can learn and retain the basics of cardiopulmonary resuscitation, even though their physical strength may pose limits on their effectiveness, researchers found.
Fully 86 percent of children ages 9 to 18 performed CPR correctly, although the chest compressions and ventilation volumes those with lower BMI delivered were of limited effectiveness, Dr. Fritz Sterz, of the Medical University of Vienna, and colleagues reported online in Critical Care.
"Young age does not limit the learning of CPR cognitive skills," the researchers said. "But lack of physical strength may."
Whether kids have the physical and cognitive skills necessary to correctly perform the complex tasks involved in CPR has not been well studied.
So the researchers looked at data on 147 youths ages 9 to 18 in 11 schools in Austria who received six hours of CPR training from their teachers in 2006. Instruction was given using the old CPR recommendation of 30 chest compressions followed by two breaths.
The researchers found that although nearly nine out of 10 students performed CPR correctly, only 69 percent tilted the mannequin's head sufficiently for mouth-to-mouth resuscitation.
Also, the median depth of chest compressions was 35 mm -- just shy of the bottom limit of 38 mm suggested for adults -- and the median number of compressions per minute was 129 bpm.
The researchers said that there was a significant relationship between the depth of chest compressions and BMI, weight, and height.
BMI of 15 or greater was associated with satisfactory chest compression.
Also, boys performed significantly deeper chest compressions than girls.
The median air volume delivered was 540 mL, and weight and BMI were significant factors in determining tidal volume delivered during mouth-to-mouth resuscitation.
"Age did not influence the depth of chest compressions or tidal volume of mouth-to-mouth resuscitation, suggesting that children as young as 9 years old could effectively learn such critical skills," the researchers said.
They said the retention and performance of the students is "compelling" in that it is "remarkably similar, if not better, than that reported in adults."
"The data support the concept that CPR training can be taught and learned by school children, and that CPR education can be implemented effectively in primary schools at all levels," they said.
Even if a child administering CPR would not prove effective for an adult patient, the researchers added, kids could help others of their age by knowing vital skills that improve the chances of survival, including early alerting of emergency medical services.
Dr. Benjamin Abella, of the Center for Resuscitation Science at the University of Pennsylvania, said that schools "represent an important and largely untapped opportunity to broadly educate our communities about CPR and saving lives."
"We always tend to give kids too little credit regarding how much they can understand and process about serious adult issues," Abella said. "Choosing the age for training is important, but teenagers are certainly eager and willing students for practical and important life training such as CPR."
Dr. Douglas Zipes, of Indiana University School of Medicine, said that CPR "should be taught in high school along with typing and drivers' ed."
"I suppose there may be some emotional problems if the person dies despite the youngster's help," Dr. Zipes said. "But the overall benefits exceed any drawbacks."
But not all physicians agree. Dr. Arthur L. Kellermann, of Emory School of Medicine in Atlanta, said the emphasis on who should learn CPR is misplaced.
"The people most likely to suffer cardiac arrest are between 65 and 75," Dr. Kellermann said. "The people who need to know CPR are the spouses of those victims."
"I don't think [teaching kids CPR] is going to transform the unacceptably low rates of CPR around the country," he added.
The researchers noted that their study had no control group, although most CPR studies don't include one. They also acknowledged that they didn't examine data on children under 9 years of age.