Efficacy of the different cardiopulmonary resuscitation (CPR) positions for chest compression and ventilation during a 2-min CPR test
| Dual operator CPR | Over-the-head CPR | Lateral CPR | Alternating CPR | Significance | |
| Chest compressions | |||||
| Number of chest compressions | 180 (175–185) | 155 (150–161) | 152 (149–161) | 149 (139–153) | ‡, §, ¶, **, ††, ‡‡ |
| Rate of compressions (per min) | 106 (105–111) | 106 (105–110) | 106 (104–109) | 106 (105–111) | |
| Chest compressions correct | 148 (84–171) [82.2%]* | 119 (96–142) [76.8%]* | 122 (74–146) [80.3%]* | 109 (89–131) [73.2%]* | ‡, §, ¶ |
| Depth 40–50 mm | 163 (127–175) [90.6%]* | 139 (116–149) [89.7%]* | 141 (112–149) [92.8%]* | 127 (109–143) [85.2%]* | ‡, §, ¶ |
| Depth <40 mm | 7 (1–29) [3.9%]* | 3 (1–19) [1.9%]* | 4 (1–13) [2.6%]* | 5 (1–16) [3.4%]* | ¶ |
| Depth >50 mm | 1 (0–8) [0.6%]* | 1 (0–21) [0.6%]* | 3 (0–12) [2.0%]* | 1 (0–15) [0.7%]* | |
| Correct hand position | 179 (172–184) [99.4%]* | 150 (134–156) [96.8%]* | 150 (139–154) [98.7%]* | 143 (125–150) [96.0%]* | ‡, §, ¶, ††, ‡‡ |
| Complete recoiling | 177 (167–182) [98.3%]* | 150 (144–158) [96.8%]* | 150 (145–155) [98.7%]* | 142 (130–150) [95.3%]* | ‡, §, ¶, ††, ‡‡ |
| Depth of chest compressions (mm) | 43 (41–45) | 44 (42–48) | 44 (42–47) | 44 (42–46) | ‡, §, ¶ |
| Inflations | |||||
| Number of inflations | 10 (10–12) | 10 (8–10) | 10 (8–10) | 8 (8–10) | ‡, §, ¶, ††, ‡‡ |
| Tidal volume 400–600 ml | 4 (2–7) [40.0%]† | 5 (1–6) [50.0%]† | 3 (0–5) [30.0%]† | 4 (2–6) [50.0%]† | §, **, ‡‡ |
| Tidal volume <400 ml | 4 (1–8) [40.0%]† | 4 (1–7) [40.0%]† | 6 (3–8) [60.0%]† | 3 (1–7) [37.5%]† | §, **, ‡‡ |
| Tidal volume >600 ml | 0 (0–2) [0.0%]† | 0 (0–2) [0.0%]† | 0 (0–0) [0.0%]† | 0 (0–1) [0.0%]† | §, **, ‡‡ |
| Tidal volume (ml) | 424 (342–522) | 415 (279–507) | 345 (218–425) | 401 (293–493) | §, ¶, **, †† |
| Hands-off time | |||||
| Time required for 2 inflations (s) | 3.3 (2.7–3.8) | 6.8 (6.2–7.5) | 7.3 (6.2–7.8) | 8.8 (7.1–10.0) | ‡, §, ¶, **, ††, ‡‡ |
| Total hands-off time (s) | 18 (15–20) | 31 (28–34) | 31 (29–34) | 36 (32–41) | ‡, §, ¶, ††, ‡‡ |
| In proportion to total CPR time (%) | 14.6 (12.5–16.7) | 25.8 (23.3–28.3) | 25.8 (24.2–28.3) | 30.0 (26.9–34.0) | ‡, §, ¶, ††, ‡‡ |
The term ‘rate of compressions’ refers to the frequency and not to the number of chest compressions. Data are shown as median (first and third quartile). p<0.05 was considered significant.
↵* Percentage refers to total number of chest compressions.
↵† Percentage refers to total number of inflations.
↵‡ p<0.05 dual operator versus over-the-head position.
↵§ p<0.05 dual operator versus lateral position.
↵¶ p<0.05 dual operator versus alternating position.
↵** p<0.05 lateral versus over-the-head position.
↵†† p<0.05 alternating versus over-the-head position.
↵‡‡ p<0.05 lateral versus alternating position.