Metronome app versus a mentally hummed song to improve the quality of chest compressions

Eva González Martínez, José Ríos Guillermo, Ricard Valero Castell, Carmen Gomar Sancho, Isabel Belda Tortosa, Enrique Jesus Carrero Cardenal

Resumen


Aim: To compare the usefulness of two strategies for improving chest compression performance: following a mobile phone metronome app versus ‘mentally humming’ a familiar popular song, ‘La Macarena’.

Methods: Controlled study of three clusters of medical student volunteers performing uninterrupted chest compressions for 2 minutes on a manikin. The clusters were assigned to receive no aid for compression timing (controls), to follow a metronome app set to 103 beats per minute, or to time compressions to the silent humming of ‘La Macarena’, a song with the same beat. We recorded demographic variables, delay in starting compressions, and performance quality variables using Resusci Anne Wireless SkillReporter software. The students also answered a satisfaction questionnaire. Data were analysed by intention-to-treat and per-protocol.

Results: We included 164 students. The median (interquartile range) percentage of compressions at the recommended rate of 100–120 cpm was nearly four-fold higher in the app group (91% [87%–94%]) and three-fold higher in the music group (74% [8%–98%]) than in the control group (24% [1%–92%]) (p<0.001). Although the app group had better overall performance scores, they started their compressions later. No group achieved the targeted depth of 5 cm. The guidance method was rated higher in the app group than the music group.

Conclusion: Mentally humming a familiar song with an appropriate beat, such as ‘La Macarena’, facilitates rapid initiation of cardiopulmonary resuscitation and improves the quality of compressions almost as much as following a metronome app.


Palabras Clave


Cardiopulmonary resuscitation; Chest compressions; Mobile applications; Music