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. 2021 Aug 6;38(10):1042–1051. doi: 10.1097/EJA.0000000000001580

Table 2.

Intra-operative characteristics

Non-OLS (n = 130) OLS (n = 130) P value
Immediately before surgery
 PEEP (cmH2O) 0 [0 to 0] 8 [8 to 8] <0.001
 Fraction of inspired oxygen (%) 45 [44 to 45] 45 [44 to 45] 0.679
 Tidal volume (ml kg−1 PBW) 7.6 ± 0.7 7.5 ± 0.6 0.343
 Respiratory rate (breaths min−1) 12 [12 to 12] 12 [12 to 12] 0.346
 Peak pressure (cmH2O) 14 ± 3 17 ± 2 <0.001
 Plateau pressure (cmH2O) 11 ± 2 14 ± 2 <0.001
 Driving pressure (cmH2O) 11 ± 2 6 ± 2 <0.001
 Respiratory compliance (ml cmH2O−1) 34 ± 8 50 ± 13 <0.001
1.5 h after pneumoperitoneum
 PEEP (cmH2O) 0 [0 to 0] 8 [8 to 8] <0.001
 Fraction of inspired oxygen (%) 45 [44 to 45] 45 [45 to 45] 0.279
 Tidal volume (ml kg−1 PBW) 7.1 ± 0.8 7.0 ± 0.7 0.179
 Respiratory rate (breaths min−1) 16 [15 to 18] 16 [15 to 18] 0.283
 Peak pressure (cmH2O) 21 ± 4 24 ± 3 <0.001
 Plateau pressure (cmH2O) 17 ± 4 20 ± 3 <0.001
 Driving pressure (cmH2O) 17 ± 4 12 ± 3 <0.001
 Respiratory compliance (ml cmH2O−1) 21 ± 6 27 ± 8 <0.001
PaO2/FiO2 (kPa) 49.7 ± 14.7 58.8 ± 12.1 <0.001
Lung recruitment manoeuvres (times) 0 [0 to 0] 7 [6 to 8] <0.001
Duration of surgery (min) 214 ± 80 212 ± 81 0.817
Duration of mechanical ventilation (min) 230 ± 82 229 ± 81 0.951
Trendelenburg position 109 (83.8) 98 (75.4) 0.123
Pneumoperitoneum pressure (mmHg) 12 [11 to 12] 12 [11 to 12] 0.105
Duration of pneumoperitoneum (min) 164 ± 73 158 ± 74 0.512
Muscle relaxant antagonist 121 (96.0) 122 (94.6) 0.769
Epidural analgesia 129 (99.2) 129 (99.2) 1.000
Urine output (ml) 500 [300 to 712] 500 [300 to 700] 0.334
Blood loss (ml) 50 [50 to 100] 50 [50 to 100] 0.290
Volume of fluids administered (ml) 3161 ± 695 3227 ± 663 0.436
 Crystalloid (ml) 2039 ± 488 2025 ± 505 0.831
 Red blood cell infusion 5 (3.8) 6 (4.6) 1.000

Data are number (%), mean ± SD or median [IQR]. Ten patients in each group were excluded from the study. OLS, open-lung strategy; PBW, predicted body weight; PEEP, positive end-expiratory pressure. Respiratory compliance = tidal volume/(peak pressure − PEEP); driving pressure = plateau pressure − PEEP.