Using a metronome during pediatric CPR may save lives, according to a new study published in the journal Pediatrics.

Each year, about 9,500 children experience an out of hospital, nontraumatic cardiac arrest in the United States, according to the Sudden Cardiac Arrest Foundation. Of these, 7,700 receive treatment from EMS. However, survival to hospital discharge after EMS treatment is only 5.4 percent — with approximately 7,000 fatalities in pediatric patients each year.

Previous research shows that using a metronome improves compression and ventilation rates on a standard adult-sized manikin. Current "hands only" CPR techniques focus on compressions over ventilation.

The authors of this study sought to determine whether using a metronome would improve chest compression rate and depth during CPR on a pediatric manikin. The researchers enrolled 155 pediatric residents, medical students, fellows and nurses into the simulation-based study. All were certified with a minimum of basic life support training.

The researchers asked the participants to perform two rounds of CPR on the pediatric manikin — one round with the metronome and one round without it. The investigators randomly assigned the participants to one of two groups — one group would use the metronome on the first round of CPR, and the other group would use the metronome on the second round of resuscitation. Each round of CPR lasted for two minutes with a 15-minute break between the two rounds.

During each round, the manikin measured the hand position, rate, depth, release time and the downstroke/upstroke ratio of delivered compressions. At 72 percent with the use of a metronome and 50 percent without it, the use of the metronome significantly improved the mean percentage of compressions delivered during CPR. Use of a metronome did not cause a significant difference in depth of the compressions.

Medical students and pediatric residents/fellows showed the most improvement in the percentage of adequate compression rate of within an acceptable rate of 90-100 compressions per minute when using a metronome.

Medical students achieved an adequate compression rate of 73 percent using a metronome and only 55 percent without one. Pediatric residents and fellows reached an adequate compression rate of 84 percent, compared with only 48 percent without the audible assist. Interestingly, nurses showed the least improvement at 48 percent adequate compression rate without the metronome and 46 percent with it.

The authors of the study concluded the use of a metronome could optimize the rate of chest compressions during pediatric CPR. The study is limited in that simulations can never replicate real code situations. Furthermore, the study parameters did not require the participants pause for ventilations nor did it assess fatigue or gather feedback.

In spite of these limitations, the results should encourage the investigation of the use of metronomes when administering CPR to the pediatric population.