Comparison of hands-off time during CPR with manual and semi-automatic defibrillation in a manikin model

SummaryBackgroundRhythm analysis with current semi-automatic external defibrillators (AEDs) requires mandatory interruptions of chest compressions that may compromise the outcome after cardiopulmonary resuscitation (CPR). We hypothesised that interruptions would be shorter when the defibrillator was operated in manual mode by trained and certified ambulance personnel.Materials and methodsSixteen pairs of ambulance personnel operated the defibrillator (Lifepak®12) in both semi-automatic (AED) and manual (MED) mode in a randomised, cross-over manikin CPR study, following the ERC 2000 Guidelines.ResultsMedian time from last chest compression to shock delivery (with interquartile range) was 17 s (13, 18) versus 11 s (6, 15) (mean difference (95% CI) 6 s (2, 10), p = 0.004). Similarly, median time from shock delivery to resumed chest compressions was 25 s (22, 26) versus 8 s (7, 12) (median difference 13 s, p = 0.001) in the AED and MED groups, respectively. While sensitivity for identifying ventricular fibrillation (VF) in both modes and specificity in the AED mode were 100%, specificity was 89% in manual mode. Thus, some unwarranted shocks resulting in hands-off time (time without chest compressions) were given in manual mode. However, mean hands-off-ratio (time without chest compressions divided by total resuscitation time) was still lower, 0.2 s (0.1, 0.3) versus 0.3 s (0.28, 0.32) in manual mode, mean difference 0.10 s (0.05, 0.15), p = 0.001.ConclusionParamedics performed CPR with less hands-off time before and after shocks on a manikin with manual compared to semi-automatic defibrillation following the 2000 Guidelines. However, 12% of the shocks given manually were inappropriate.