Usefulness of a metronome to improve quality of chest compressions during cardiopulmonary resuscitation.

The objective of this study was to improve the quality of chest compressions after the introduction of a metronome during cardiopulmonary resuscitation (CPR). A retrospective analysis of Zoll® compression data of 219 in-hospital adult participants who received CPR from January 2017 to December 2018 was done. A metronome was introduced during chest compressions in January 2018, and the 2017 data served as the control. The main outcome measure compared the overall quality of chest compressions measured by the rate (100 to 120 compressions per minute), depth (2.0 to 2.4 inches), and mean release velocity (≥400 mm/sec) on chest recoil. Compared to control, the metronome group had a statistically significant improvement of the mean percent compression rate within 100 to 120 beats per minute: 28.16% vs. 71.14% (P < 0.001) and a statistically significant improvement of the mean percent compression depth within 2.0 to 2.4 inches: 29.35% vs. 34.84% (P = 0.03). However, there was no statistically significant improvement of mean percent release velocity ≥400 mm/second: 47.41% vs. 51.09% (P = 0.38). Our data suggest that an inexpensive and widely available intervention may improve the quality of CPR. We suggest that further research be conducted to measure patient clinical outcomes.