Table 3.
Intraoperative Procedures
| Variable | Open-lung Ventilation (n = 43) | Control Ventilation (n = 43) | P Value |
|---|---|---|---|
| Tidal volume, mean ± SD, ml/kg of predicted body weight | 6.5 ± 1.0 | 6.8 ± 1.0 | 0.231 |
| Intraoperative PEEP, median (interquartile range), cm H2O | |||
| Minimum level | 4 (0–5) | 2 (0–2) | < 0.001 |
| Maximum level | 8 (8–8) | 2 (2–2) | < 0.001 |
| Mode level* | 6 (6–8) | 2 (2–2) | < 0.001 |
| Recruitment maneuver, n (%)† | < 0.001 | ||
| At least 1 | 43 (100) | 7 (16.3) | |
| At least 2 | 35 (81.4) | 0 | |
| At least 3 | 34 (79.1) | 0 | |
| At least 4 | 29 (67.4) | 0 | |
| More than 4 | 27 (62.7) | 0 | |
| Inspired oxygen fraction | |||
| Anesthesia onset | 0.49 ± 0.07 | 0.53 ± 0.07 | 0.040 |
| End of surgery | 0.48 ± 0.09 | 0.54 ± 0.07 | 0.011 |
| CPB duration, mean ± SD, min | 93 ± 23 | 90 ± 33 | 0.663 |
| Aortic cross clamp duration, mean ± SD, min | 68 ± 21 | 67 ± 28 | 0.837 |
| Mammary artery harvesting, n (%) | 1.0 | ||
| None | 28 (65.1) | 28 (65.1) | |
| Unilateral | 7 (16.3) | 7 (16.3) | |
| Bilateral | 8 (18.6) | 8 (18.6) | |
| Volume of fluids administered, mean ± SD, ml | |||
| Crystalloid | 2000 ± 657 | 1843 ± 500 | 0.223 |
| Colloid | 788 ± 365 | 618 ± 321 | 0.030 |
| Blood products transfusion, n (%) | 3 (7.0) | 4 (9.3) | 0.693 |
Predicted body weight was calculated as 50 + 0.91 × (height in cm − 152.4) for men and 45.5 + 0.91 × (height in cm − 152.4) for women. Data come from n = 49 for inspired oxygen fraction. CPB, cardiopulmonary bypass; PEEP, positive end-expiratory pressure.
*
Mode PEEP level corresponds to intraoperative PEEP that was applied most of the time after review of ventilation settings trends of the dedicated ventilator screen.
†
Recruitment maneuver effectively performed: continuous airway pressure at 30 cm of water for 30 s.