Temporal and Weight-Related Variations in Chest Compression Quality during CPR: A 30-Second Interval Manikin Study

Background High-quality chest compressions are essential for effective cardiopulmonary resuscitation (CPR). This study aimed to evaluate the influence of rescuer sex and body weight on chest compression quality during the first two minutes, with emphasis on temporal changes within 30-second intervals. Methods In this cross-sectional simulation study, 103 healthcare providers performed three 2-minute cycles of continuous chest compressions on a manikin. Data from all cycles were analyzed; however, only first-cycle results are reported due to performance consistency across cycles. Compression quality was assessed in 30-second intervals, and weight was analyzed both continuously and using a 60-kg cutoff. The ILCOR benchmark of 200–240 compressions per 2 minutes was used for comparison. Results Female participants demonstrated a significant decline in the number of effective compressions (5–6 cm depth) after the first minute (p < 0.001), particularly in the last two intervals, whereas male participants maintained relatively stable performance (p = 0.342). Participants weighing ≥60 kg delivered significantly more effective compressions than those <60 kg (mean: 114.16 vs. 27.34 compressions; p < 0.001). Although total compression counts were higher in heavier participants, this difference was not statistically significant (p = 0.126). Notably, the mean number of effective compressions in all subgroups remained below the ILCOR-recommended range. Conclusion Rescuer sex and body weight significantly influence chest compression quality, especially depth, with females and lighter-weight individuals showing a marked decline after one minute. These findings highlight the need for careful consideration of rotation intervals and suggest that individualized CPR training strategies—accounting for physical characteristics—may improve adherence to guidelines. However, potential trade-offs, such as increased hands-off time from more frequent rescuer changes, should be carefully weighed in clinical practice. Trial registration: Not applicable Trial sponsor: Shahrekord University of Medical Science Funding: This research is financially supported by Shahrekord University of Medical Sciences. Study status: This study has been completed. Related article: No related articles for this study have been submitted to any journal. The study's sponsor and funders had no involvement in the data's design, analysis, or interpretation. The content is entirely the authors' responsibility and does not necessarily reflect the official views of the National Institutes of Health.