Compression depth, coefficient of variation (COV), decay in compression depth comparing the initial versus the last 60 s and initial and last 25 s using a 3:1, 5:1 and 15: 2 ratio number of compressions and ventilator breaths/2 min with a 3:1, 5:1 and 15:2 ratio
| Compression: ventilation ratio | 3:1 | 5:1 | 15:2 |
|---|---|---|---|
| Depth (mm) | 27±5.3 | 26.7±5.4 | 26.2±6.1 |
| Coefficient of variation (%) | 6.6±3.4 | 6.8±2.6 | 7.1±3.8 |
| Compression depth decay | |||
| Comparison initial and second 60 s | 0.36±1.72 (p=0.11) | 0.58±1.51 (p=0.02) | 0.86±1.88 (p=0.009) |
| Comparison initial 25 and last 25 s | 0.54±1.64 (p=0.036) | 0.98±2.47 (p=0.01) | 1.29±2.71 mm (p=0.007) |
| Compression rates/2 min | 194±36 | 213±41* | 225±41** |
| Ventilation breaths/2 min | 64±12*** | 42±8 | 30±5.4 |