Table 1. Baseline characteristics of the patients.
| Variable | I | II | III | IV | P |
|---|---|---|---|---|---|
| Age (years) | 55±10 | 56±12 | 52±13 | 53±9 | 0.778 |
| BMI (kg/m2) | 24.3±3.0 | 22.8±2.0 | 23.8±2.1 | 24.0±2.8 | 0.398 |
| Types of surgery | |||||
| LAP rectectomy (n) | 6 (40.0) | 8 (53.3) | 7 (46.7) | 7 (46.7) | 0.911 |
| LAP colectomy (n) | 9 (60.0) | 7 (46.7) | 8 (53.3) | 8 (53.3) | |
| Pneumoperitoneum duration (min) | 126±30 | 116±26 | 113±28 | 117±32 | 0.629 |
| Operative time (min) | 154±19 | 146±27 | 143±28 | 153±22 | 0.539 |
Group I: control group (no PEEP); Group II: received PEEP at 4 cmH2O; Group III: received PEEP at 8 cmH2O; Group IV: received PEEP at 12 cmH2O. n=15/group. Data shown as are mean ± SD or n (%). BMI: body mass index, weight (kg)/height2 (m); PEEP, positive end-expiratory pressure.