Table 1.
Characteristics of the clinical trials that included in the meta-analysis
| Study | Years | Comparator mode and tidal volume strategy | Sample size | Age (years) | PaO2/FiO2 at baseline (mmHg), mean (SD) | PaO2/FiO2 at day 3 (mmHg), mean (SD) |
|---|---|---|---|---|---|---|
| Putensen et al.[21] | 2001 | AC–PC with LVT (Vt=6 ml/kg) | AC–PC: 15 APRV: 15 | AC–PC: 42 (5) APRV: 40 (5) | AC–PC: 250 (14) APRV: 250 (14) | AC–PC: 175 (38) APRV: 320 (58) |
| Varpula et al.[22] | 2004 | SIMV + PS–PC (Vt=8–10 ml/kg) | SIMV–PC: 28 APRV:30 | SIMV–PC: 44 (4) APRV: 49 (5) | SIMV–PC: 164 (6) APRV: 150 (7) | SIMV–PC: 165 (60) APRV: 195 (76) |
| Maxwell et al.[23] | 2010 | SIMV + PS–VC with LVT (Vt=6 ml/kg) | SIMV–VC: 32 APRV:31 | SIMV–VC: 42.4 (16) APRV: 40 (14) | SIMV–VC: 363 (36) APRV: 320 (33) | SIMV-VC: 280 (32) APRV: 300 (45) |
| Li et al.[24] | 2016 | SIMV–VC (Vt=6–8 ml/kg) | SIMV–VC: 26 APRV: 26 | SIMV–VC: 53 (9) APRV: 54 (8) | SIMV–VC: 118 (36) APRV: 119 (35) | SIMV–VC: 212 (55) APRV: 220 (46) |
| Zhou et al.[25] | 2017 | AC–VC with LVT (Vt=6 ml/kg) | AC–VC: 67 APRV: 71 | AC–VC: 52 (15) APRV: 51 (15) | AC–VC: 138 (56) APRV: 121 (46) | AC–VC: 180 (68) APRV: 280 (83) |
| Hirshberg et al.[26] | 2018 | AC–VC with LVT (Vt=6 ml/kg) | AC–VC: 17 APRV: 17 | AC–VC: 51 (14) APRV: 57 (15) | AC–VC: 121 (50) APRV: 109 (67) | AC–VC: 162 (34) APRV: 168 (98) |
A/C=Assist control ventilation, AC-PC=Assisted control with pressure control ventilation, APRV=Airway pressure release ventilation, LTV=Low tidal volume, PC=Pressure control ventilation, SIMV=Synchronized intermittent mandatory ventilation