Related Experiment Video
Updated: May 20, 2026
Ultrasonographic Assessment During Cardiopulmonary Resuscitation
Published on: October 24, 2020
Induction of a shorter compression phase is correlated with a deeper chest compression during metronome-guided
Tae Nyoung Chung1, Jinkun Bae, Eui Chung Kim
1Department of Emergency Medicine, CHA University School of Medicine, Seongnam-Si, Gyeonggi-Do, Republic of Korea. hendrix74@gmail.com
Objectives:
Recent studies have shown that there may be an interaction between duty cycle and other factors related to the quality of chest compression. Duty cycle represents the fraction of compression phase. We aimed to investigate the effect of shorter compression phase on average chest compression depth during metronome-guided cardiopulmonary resuscitation.
Methods:
Senior medical students performed 12 sets of chest compressions following the guiding sounds, with three down-stroke patterns (normal, fast and very fast) and four rates (80, 100, 120 and 140 compressions/min) in random sequence. Repeated-measures analysis of variance was used to compare the average chest compression depth and duty cycle among the trials.
Results:
The average chest compression depth increased and the duty cycle decreased in a linear fashion as the down-stroke pattern shifted from normal to very fast (p<0.001 for both). Linear increase of average chest compression depth following the increase of the rate of chest compression was observed only with normal down-stroke pattern (p=0.004).
Conclusions:
Induction of a shorter compression phase is correlated with a deeper chest compression during metronome-guided cardiopulmonary resuscitation.
Related Concept Videos
01:21Cardiopulmonary Resuscitation I: Adult
01:22Cardiopulmonary Resuscitation II: ACLS Airway Management
01:29Assessment of Ventilation II: Respiratory Depth and Rhythm
Respiratory depth measures the volume of air inhaled or exhaled during a breath. It can vary from shallow to deep and typically remains consistent when a person is at rest or asleep. Occasionally, individuals will automatically inhale deeply, known as sighing, which inflates the lungs with more air than normal breathing.
To assess respiratory depth, observe the degree of chest excursion or movement: