Superior-head automated external defibrillator placement during single-rescuer cardiopulmonary resuscitation: a randomized crossover simulation study and retrospective multicenter cohort.
Xu D, Zhang J, et al. • Frontiers in public health • 2026
Superior-head AED placement (position D) improved the efficiency, compression continuity, and workload of simulated single-rescuer CPR, with retrospective clinical findings that were directionally consistent but statistically inconclusive and should be regarded as hypothesis-generating rather than confirmatory.
Key Findings
Results
Superior-head AED placement (position D) shortened compression-to-first-shock time by 14.8–26.3 seconds relative to the other three AED positions in simulation.
Study used a randomized four-sequence crossover manikin simulation with 32 healthcare providers and 128 evaluable trials.
Four prespecified AED positions were compared: superior-head placement (position D) versus alternative placements (positions A–C).
All pairwise comparisons were statistically significant after Holm adjustment (all Holm-adjusted p < 0.001).
The primary simulation outcome was compression-to-first-shock time.
Results
Superior-head AED placement increased chest compression fraction compared to other positions in simulation.
Chest compression fraction was 83% with position D versus 78–80% with positions A–C.
The difference was statistically significant (p < 0.001).
Higher chest compression fraction reflects reduced interruptions to chest compressions during AED use.
Results
Superior-head AED placement reduced AED-related hands-off time in simulation.
AED-related hands-off time was a prespecified secondary simulation outcome.
Reduction was statistically significant (p < 0.001) compared to alternative positions.
Over-body actions (reaching across the patient) were least frequent with position D.
Results
Superior-head AED placement lowered perceived rescuer workload as measured by the NASA Task Load Index.
NASA Task Load Index (TLX) was used to assess subjective workload across the four AED positions.
Position D yielded lower perceived workload compared to all other positions (all p < 0.001).
This finding was a prespecified secondary simulation outcome.
Results
Superior-head AED placement did not increase the rate of critical procedural errors in simulation.
Procedural safety was a prespecified secondary simulation outcome.
No increase in critical errors was observed with position D relative to positions A–C.
This supports the safety profile of the superior-head placement approach.
Results
In the retrospective multicenter cohort, superior-head AED placement was associated with a directionally favorable but statistically inconclusive reduction in collapse-to-first-shock interval.
The cohort included 213 AED-treated adult cardiac-arrest cases from six centers: 57 with position D and 156 with other positions.
The adjusted median difference in collapse-to-first-shock interval was -0.42 min (approximately 25 seconds; 95% CI, -0.91 to 0.07; p = 0.092).
Estimates consistently favored position D across sensitivity, restricted-cohort, weighted, and leave-one-center-out analyses.
Every confidence interval crossed the null, meaning results did not reach statistical significance.
The primary clinical outcome was the collapse-to-first-shock interval.
Results
Patient outcomes did not differ by AED position in the retrospective cohort.
Clinical patient outcomes were assessed as part of the retrospective cohort analysis.
No statistically significant differences in patient outcomes were detected between position D and other AED positions.
The retrospective cohort comprised 213 adult cardiac-arrest cases from six centers.
Conclusions
The authors conclude that prospective validation is required before clinical implementation of superior-head AED placement.
Retrospective clinical findings were characterized as 'hypothesis-generating rather than confirmatory.'
The simulation study provides mechanistic support, while the clinical data are directionally consistent but underpowered or confounded.
The study design combined a randomized crossover simulation with a retrospective cohort, each with distinct limitations.
What This Means
This research suggests that where a lone rescuer places an automated external defibrillator (AED) relative to a cardiac arrest victim matters for the efficiency of the resuscitation effort. When a single rescuer must both perform chest compressions and operate an AED, placing the AED above the patient's head (the 'superior-head' position) allowed trained healthcare providers in a simulation study to deliver the first shock about 15–26 seconds faster than when the device was placed in other locations. The superior-head position also meant fewer interruptions to chest compressions (83% compression fraction versus 78–80% with other placements) and less physical effort reported by rescuers, without causing more procedural mistakes.
The researchers also reviewed real-world cardiac arrest cases from six hospitals involving 213 patients. Among those treated by rescuers using the superior-head AED position, the time from collapse to first shock tended to be about 25 seconds shorter, but this difference was not statistically conclusive — the data could not rule out chance as an explanation. Patient survival and other clinical outcomes were similar regardless of where the AED was placed, though the study was not designed or large enough to detect differences in survival.
This research suggests that positioning an AED above a cardiac arrest victim's head may make it easier and faster for a single rescuer to use the device while maintaining continuous chest compressions. However, because the real-world clinical data were inconclusive and the simulation involved trained healthcare providers rather than lay bystanders, the authors caution that a prospective clinical study is needed before recommending this placement as standard practice.
Xu D, Zhang J, Lin H, Cai Q, Zhang S, Yan J. (2026). Superior-head automated external defibrillator placement during single-rescuer cardiopulmonary resuscitation: a randomized crossover simulation study and retrospective multicenter cohort.. Frontiers in public health. https://doi.org/10.3389/fpubh.2026.1927906