Table 2 Intraoperative ventilatory setting by group
All patients (N = 2034) | Closed abdominal surgery (N = 906) | Open abdominal surgery (N = 1128) | P–value | Absolute Difference | |
|---|---|---|---|---|---|
Ventilation mode, % (n/N) | 0.013 | Pressure–controlled 4% [1 to 8%] | |||
Volume–controlled | 77% (1571/2034) | 79% (895/906) | 75% (676/1128) | ||
Pressure–controlled | 23% (463/2034) | 21% (233/906) | 25% (230/1128) | ||
Tidal Volume | |||||
Absolute (ml) | 505 [465 to 570] | 504 [462 to 570] | 505 [465 to 572] | 0.567 | 1 [24 to 25] |
Per PBW (ml∙kg− 1) | 8.0 [7.0 to 9.0] | 8.5 [7.6 to 9.5] | 8.2 [7.4 to 9.2] | 0.001 | 0.2 [0.07 to 0.5] |
Per ABW (ml∙kg− 1) | 7.0 [6.0 to 8.0] | 6.8 [5.8 to 7.7] | 7.0 [6.1 to 7.9] | < 0.001 | 0.2 [0.1 to 0.4] |
Minute ventilation (L∙kg− 1) | 6.0 [6.0 to 7.0] | 6.5 [5.8 to 7.2] | 6.3 [5.5 to 7.0] | < 0.001 | 0.2 [0.1 to 0.4] |
Respiratory system compliance | |||||
Dynamic, ml∙cm∙H2O−1 | 26 [21 to 32] | 25 [20 to 32] | 27 [21 to 33] | < 0.001 | 2 [0 to 4] |
Static, ml∙cm∙H2O−1 | 42 [35 to 50] | 41 [33 to 50] | 43 [36 to 51] | < 0.001 | 1 [0.4 to 2] |
Routine recruitment maneuvers, % (n/N) | 12% (238/2.029) | 13% (119/905) | 11% (119/1.124) | 0.087 | 2% [1 to 5%] |
FiO2, % | 50 [45 to 56] | 54 [48 to 70] | 50 [45 to 63] | < 0.001 | 4 [4 to 10] |
SpO2, % | 99 [98 to 100] | 99 [98 to 100] | 99 [98 to 100] | < 0.001 | 0 [0 to 0]a |
EtCO2, kPa | 4.0 [4.0 to 5.0] | 4.6 [4.2 to 4.9] | 4.3 [4.0 to 4.7] | < 0.001 | 0.2 [0.2 to 0.6] |
Airway pressures | |||||
Driving pressure | |||||
Time–weighted average (cmH2O∙hour−1) | 8 [6 to 11] | 8 [6 to 11] | 8 [6 to 10] | 0.091 | 0.2 [0.09 to 1.2] |
Maximum value (cmH2O) | 14 [11 to 18] | 16 [12 to 20] | 14 [11 to 17] | < 0.001 | 2 [2 to 7] |
Minimum value (cmH2O) | 11 [9 to 14] | 11 [9 to 15] | 11 [9 to 14] | 0.008 | 0 [0 to 17] |
Coefficient of variation (%) | 10 [5 to 20] | 15 [6 to 26] | 9 [4 to 15] | < 0.001 | 5 [4 to 8] |
Peak pressure | |||||
Time–weighted average (cmH2O∙hour−1) | 12 [9 to 15] | 11 [9 to 15] | 12 [9 to 15] | 0.414 | 0.2 [0.1 to 1.1] |
Highest value (cmH2O) | 20 [17 to 24] | 21 [18 to 26] | 19 [16 to 23] | < 0.001 | 2 [2 to 10] |
Lowest value (cmH2O) | 16 [14 to 20] | 17 [14. to 20] | 16 [14 to 20] | 0.011 | 1 [1 to 3] |
Coefficient of variation (%) | 8 [4 to 15] | 11 [5 to 19] | 7 [3 to 12] | < 0.001 | 5 [3 to 6] |
PEEP | |||||
Time–weighted average (cmH2O∙hour−1) | 2 [1 to 3] | 2 [1 to 4] | 2 [1 to 3] | 0.019 | 0 [0 to 0] |
Highest value (cmH2O) | 5 [2 to 5] | 5 [2 to 5] | 5 [2 to 5] | 0.255 | 0 [0 to 0] |
Lowest value (cmH2O) | 4 [0 to 5] | 4 [0 to 5] | 3 [0 to 5] | 0.186 | 1 [1 to 5] |
Coefficient of variation (%) | 0 [0 to 22] | 0 [0 to 22] | 0 [0 to 22] | 0.579 | 0 [0 to 0] |