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Three Part Question

In [patient receiving cardiopulmonary resuscitation] is [metronome] better at [improving the quality of chest compression]?

Clinical Scenario

Paramedics often perform cardiopulmonary resuscitation in out-of-hospital setting. Dynamic yet stressful environment may hinder them to perform quality cardiopulmonary resuscitation.

Search Strategy

Pubmed 2013-2023
[(Metronome) AND (cardiopulmonary resuscitation)] OR [(Metronome) AND (chest compression)] AND (simulation OR manikin) AND [English(Filter)] AND [freefulltext(Filter)]

Search Outcome

12 papers were found, of which 8 are irrelevant. Relevant papers are summarized in the following table.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Caliskan et al. 2021 Turkey	102 resident physicians	Prospective simulation study (II)	Compression depth, rate, and full chest recoil	Optimal chest compression rate, depth and complete recoil was better with metronome use	No randomization mentioned in the study. CPR duration limited to 2 min, effect of the metronome on the development of fatigue in prolonged CPR was not investigated. Simulation so may not extrapolate to clinical care. Different chest compliance of manikin to human.
Takano et al. 2022 Japan	48 lay rescuers with no CPR training before	Prospective simulation study (II)	Compression rate, depth and chest compression fraction	Chest compression fraction was higher in the Coaching Group; the depth increased over time in the Coaching Group	Lay people were recruited. Continuous verbal encouragement to provide deeper compressions was also given. Short CPR simulation (2 mins). Simulation so may not extrapolate to clinical care. Different chest compliance of manikin to human.
Bae J et al. 2015 Korea	42 senior medical and paramedic students	Prospective crossover trial simulation study (II)	Average compression rate and depth, duty cycle (%), and fractions of chest compressions with incomplete release and incorrect hand position (%)	Average compression depths were significantly different according to the rate used in training (p<0.001).	Simulation of chest compression only CPR, which may not represent all aspects of a real clinical setting. Different chest compliance of manikin to human.
Tanaka et al. 2019 Japan	642 laypeople as CPR trainees	Randomized control trial, simulation study (I)	Compression rate and depth, percentage of adequate depth and recoil	The QCPR Classroom group with metronome sound and real-time visual feedback had significantly better adequate depth and recoil than control group	Laypeople were included. Only 1 min of chest compression was conducted for measurement. Simulation may not extrapolate to clinical care. Different chest compliance of manikin to human.

Comment(s)

High quality of CPR, including proper external chest compression (ECC), is crucial for favorable cardiac resuscitation outcomes. High-quality CPR involves minimizing interruptions, providing compressions at the recommended rate, depth and preventing excessive ventilation. The American Heart Association (AHA) recommends a compression rate of 100-120 per minute, as rates below or above this range are associated with lower survival rates. Real-time CPR feedback tools like metronomes can help maintaining consistent compression rates close to the target range. Metronomes produce regular audible beats per minute, serving as a cost-effective and practical guidance method during manual CPR. According to Caliskan et al. (2021), the use of a metronome during CPR improved compression depth and chest recoil in a simulation-based study with resident physicians. Takano et al. (2022) found that continuous coaching with metronome sound and verbal encouragements led to higher compression depth and fraction over time in layperson CPR training. Bae et al. (2015) conducted a crossover trial with medical and paramedic students, revealing that different chest compression rates in previous training significantly affected compression depth in metronome-guided CPR. Besides, Tanaka et al. (2019) reported that the QCPR Classroom group, which received real-time visual feedback and a metronome sound, demonstrated significantly better compression depth and recoil compared to the control group in laypeople undergoing CPR training.

Editor Comment

Update to https://bestbets.org/bets/bet.php?id=2550

Clinical Bottom Line

The use of a metronome can improve the quality of CPR performance, including compression rate, depth and chest recoil.

References

1. Caliskan et al. Effects of metronome use on cardiopulmonary resuscitation quality Turk J Emerg Med 2021 Feb 12 ; 21(2):51-55
2. Takano et al. Effect of Coaching with Repetitive Verbal Encouragements on Dispatch-Assisted Cardiopulmonary Resuscitation: A Randomized Simulation Study J Emerg Med 2022 Aug ; 63(2):240-246.
3. Bae J et al. Effect of the rate of chest compression familiarised in previous training on the depth of chest compression during metronome-guided cardiopulmonary resuscitation: a randomised crossover trial BMJ Open 2016 Feb 12 ; 6(2):e010873.
4. Tanaka et al. Effect of real-time visual feedback device 'Quality Cardiopulmonary Resuscitation (QCPR) Classroom' with a metronome sound on layperson CPR training in Japan: a cluster randomized control trial BMJ Open 2019 Jun 11 ; 9(6):e026140.