Total compressions | No feedback period (N = 27,295) | Feedback period (N = 27,965) | P-value |
---|---|---|---|
Adequate depth and rate | 4,584 (16.8) | 3,300 (11.8) | < 0.01 |
Mean compression depth (cm) | 6.1 (1.8) | 6.7 (1.9) | < 0.01 |
Compression depth |  |  | < 0.01 |
 < 5.0 cm | 7,238 (26.5%) | 5,285 (18.9%) | |
 5.0–6.0 cm | 6,035 (22.1%) | 4,732 (16.9%) |  |
 > 6.0 cm | 14,022 (51.4%) | 17,948 (64.2%) |  |
 Mean compression rate (/min) | 111.9 (11.2) | 112.0 (13.0) | 0.25 |
Compression rate |  |  | < 0.01 |
 < 100 /min | 2,338 (8.6%) | 3,330 (11.9%) | |
 100–120 /min | 20,621 (75.5%) | 18,816 (67.3%) |  |
 > 120 /min | 4,336 (15.9%) | 5,819 (20.8%) |  |
 Mean chest compression release velocity (mm/sec) | 371 (125) | 426 (130) | < 0.01 |
Chest compression release velocity |  |  | < 0.01 |
 ≥ 400 mm/sec | 10,546 (38.6%) | 15,853 (56.7%) | |
 300–399 mm/sec | 8,716 (31.9%) | 8,246 (29.5%) |  |
 < 300 mm/sec | 8,033 (29.4%) | 3,866 (13.8%) |  |
 Return of spontaneous circulation | 16 (53.3%) | 14 (46.7%) | 0.61 |
 ECMO insertion after arrest | 2 (6.7%) | 6 (20.0%) | 0.13 |
 Survival to discharge | 1 (3.3%) | 0 (0.0%) | 0.31 |